Be afraid... Be VERY Afraid

[DanielDTech]

http://wap2p.com/sdbeta_images/uploaded/render5 modified.JPG


If anyone can correctly guess what this is, I solemnly swear that I will send you $15.00 on paypal before kickoff.

http://wap2p.com/sdbeta_images/uploaded/top view.jpg

[Andrew Lawrence]

So what's with only 1 CIM motor and the tiny wheel in the back? What's the use of this? Looks beautiful, but seems like you're sacrificing a whole motor's worth of power for an interesting design.

EDIT: It's a picture of CAD model. I'll take my $15 now.

[ehfeinberg]

I am afraid!

It looks like instead of shifting gears you are shifting wheels. I would love to know the gear ratios for each wheel.

Beautiful design and beautiful CAD. I can't wait to see this on an actual robot!

[aboppana]

is it a swerve module with some sort of shifting wheel assembly? are you going for smaller wheels for when you want more torque and less speed and then bigger wheels for more speed or something like that?

great job on the cad!
can't wait to see what it actually is
does look very menacing!:ahh:

[MichaelBick]

Is it a 2 speed transmission where you shift which wheel is on the ground to shift the speed?

[DanielDTech]

So what's with only 1 CIM motor and the tiny wheel in the back? What's the use of this? Looks beautiful, but seems like you're sacrificing a whole motor's worth of power for an interesting design.

EDIT: It's a picture of CAD model. I'll take my $15 now.

You'll know what the use is on January 5th! And I assure you that:
- the CIM motor isn't wasted at all
- this is not only an interesting design, but a revolutionary one, in and beyond FRC

[Andrew Lawrence]

is it a swerve module with some sort of shifting wheel assembly? are you going for smaller wheels for when you want more torque and less speed and then bigger wheels for more speed or something like that?

great job on the cad!
can't wait to see what it actually is
does look very menacing!:ahh:

Correct me if I'm wrong, but smaller wheels don't give you more torque. They do reduce the distance traveled per rotation but there should be same amount of rotational force on the shaft, regardless of wheel size. While they are probably geared differently, there's no advantage that I can see of having different sized wheels for different speeds or more torque. A shifter would accomplish that without the need for an extra wheel.

[Andrew Lawrence]

Actually, new question (I'm sure you can answer this without giving away what this magnificent machine is) - Is the smaller wheel powered?

[DanielDTech]

Actually, new question (I'm sure you can answer this without giving away what this magnificent machine is) - Is the smaller wheel powered?

Yes, both wheels are simultaneously powered :D

[DanielDTech]

You're all surprisingly close :ahh: ... This does indeed have something to do with shifting, I'll tell you that. But there's something HUGE that you guys are missing, the same "thing" that will get you those 15 bucks :P

[Gregor]

I can't say what, but I can ask why!

[MichaelBick]

Correct me if I'm wrong, but smaller wheels don't give you more torque. They do reduce the distance traveled per rotation but there should be same amount of rotational force on the shaft, regardless of wheel size. While they are probably geared differently, there's no advantage that I can see of having different sized wheels for different speeds or more torque. A shifter would accomplish that without the need for an extra wheel.

Smaller wheels will give you more torque. Think of a wheel like a pinion on a rack, except there is no teeth. IF you reduce the pinion size you get more torque but less speed.

Is this the completed assembly? Another guess of mine is that in addition to having different speeds, based on which wheel is touching the ground, you could have different wheel bases. So basically, in one orientation(likely the one with the higher speed) you have a smaller wheel base, therfore you can turn easily. On the other hand, when the other wheel is touching the ground(likely the lower speed), you will have a larger wheel base and therefor it will be harder for you opponents to turn you.

[CalTran]

Oh good, now I don't feel so bad at looking at the CAD model (Which looks beautiful, by the way) and being absolutely dumbfounded about what it actually is. While the guess that it is a shifting wheel, as it stands right now it doesn't appear that either of the wheels are actuated (Might just be the angle).

I'm intrigued as to how this would be a revolutionary design both in and outside of FIRST. Perhaps once light is shed on its design I will be able to figure out how revolutionary it is.

[ehfeinberg]

What I'm really confused about is where is the motor/cylinder which changes which wheel is touching the ground. If there is no such mechanism, it would do really great on a bumpy field.

I don't suppose we could get a top/bottom view.

[JosephC]

I propose three ideas.

1. Both "wheels" touch the ground at the same time.

2. The "wheels" aren't actually for driving.

3. The whole assembly pivots back and forth. This would work well for bumpy fields/ off road applications outside of FIRST.

[DanielDTech]

I propose three ideas.

1. Both "wheels" touch the ground at the same time.

2. The "wheels" aren't actually for driving.

3. The whole assembly pivots back and forth. This would work well for bumpy fields/ off road applications outside of FIRST.

1 and 2 are wrong. 3 is partially correct!

[Andrew Lawrence]

So it's like Octocanum but switching between two traction wheels (for different speeds/wheelbases).

[dodar]

Is the smaller wheel a kind of wheelie-bar? Such that if you are climbing something, when the bigger wheel starts to climb, the bottom wheel stays in contact with the ground.

[DanielDTech]

Oh good, now I don't feel so bad at looking at the CAD model (Which looks beautiful, by the way) and being absolutely dumbfounded about what it actually is. While the guess that it is a shifting wheel, as it stands right now it doesn't appear that either of the wheels are actuated (Might just be the angle).

I'm intrigued as to how this would be a revolutionary design both in and outside of FIRST. Perhaps once light is shed on its design I will be able to figure out how revolutionary it is.

Thank you for the CAD compliment! And yes, it's just the angle. Both wheels are actuated as a matter of fact.

[aboppana]

Smaller wheels will give you more torque. Think of a wheel like a pinion on a rack, except there is no teeth. IF you reduce the pinion size you get more torque but less speed.


This is how I usually think of it.

Anyways, is there a reason you are using belts and not gears for this? Is it for a more quiet operation?

Are the wheels of different material? Is one grippy for more traction but one slippery for ease of turning? Maybe this isn't a swerve, but a fixed unit and you have the slippery wheels to ease turning a 4-wheel long bot. But I doubt its as simple as this ;)

[JosephC]

Could we get a top down view?

[dodar]

Wait, the slot near the big wheel looks the same size as the other side. Can this thing flip 180 degrees?

[DanielDTech]

So it's like Octocanum but switching between two traction wheels (for different speeds/wheelbases).

That is the closest guess yet. But again, you're missing something huge... The part that I think is pretty difficult for anyone to guess, otherwise I wouldn't put $15 bucks on it :D

[EricH]

980 in 2003 used something very similar, using smaller wheels for speed and larger wheels for climbing a ramp (at least, that's what I recall them doing--it might have been the other way around). I think some other teams have done something similar. We've also seen swapping mecanums and traction wheels, as well as omnis and traction wheels. I designed one once, but it didn't get past the team brainstorming stage.


This is one quarter of a wheel-shifting drivetrain, where two different types of wheel can be changed at will, or used for climbing. Again, I don't think this is exactly revolutionary for FRC--similar things have been done on several occasions.


Now, the real question is: have you locked into using this for next year? If so, I highly suggest reconsidering. Quite simply, you don't know what the game will involve. (Hey, wheel-less robots are always an option for the GDC...) So, the thing that I'm more afraid of is: http://www.andymark.com/product-p/am-superoptions.htm

[CalTran]

I don't think it flips 180, as that CIM will have a hard time going through the mounting material. I think it's just aesthetically pleasing.

[Ankit S.]

The wheels seem cantilevered. I think thats different from the usual octanum setup.

[Garret]

I am just going to guess that it is some sort of mechanical automatic transmission. That shifts into a high torque mode when placed under additional load (such as being pushed or accelerating from standstill). Another possibility is that when this runs into something the wheels end up lifting up the robot to allow it to climb objects such as stairs or the barrier from this year easier.

Anyways beautiful model, I appreciate the detail and the actual teeth on the belt.

[Starke]

In 2004, HOT (67) had a very similar system where they had two wheels on each side of the robot that were powered by the same motor. Each wheel was actuated downward to touch the ground. This allowed them to change speed/torque ratios.

Notice the two different size black treaded wheels on the right side of the robot in the picture below.

http://www.chiefdelphi.com/media/img/224/22478d3b31f9941bf57f173ee2ad277e_m.jpg

[DanielDTech]

980 in 2003 used something very similar, using smaller wheels for speed and larger wheels for climbing a ramp (at least, that's what I recall them doing--it might have been the other way around). I think some other teams have done something similar. We've also seen swapping mecanums and traction wheels, as well as omnis and traction wheels. I designed one once, but it didn't get past the team brainstorming stage.


This is one quarter of a wheel-shifting drivetrain, where two different types of wheel can be changed at will, or used for climbing. Again, I don't think this is exactly revolutionary for FRC--similar things have been done on several occasions.


Now, the real question is: have you locked into using this for next year? If so, I highly suggest reconsidering. Quite simply, you don't know what the game will involve. (Hey, wheel-less robots are always an option for the GDC...) So, the thing that I'm more afraid of is: http://www.andymark.com/product-p/am-superoptions.htm

No, we're not 100% sure that we'll use it this season, for that reason exactly. As for your guess, you are on track, but still very wrong. This is certainly revolutionary, keep in mind that there is a HUGE concept that you're not seeing here.

[rcmolloy]

I hate to do this but here's a much larger image for everyone's viewing pleasure.

http://i.imgur.com/yzSjv.jpg

Also, I'm probably 100% wrong but it could possibly be that you have an 8WD narrowed down to a single module.

[ehfeinberg]

Well, it looks like by changing which wheel touches the ground, you can also change the clearance under the chassis. The hard stop looks like the vertical mounting touching the cim (The piece of metal which looks like a bell curve in the back). It looks like you could add 3, 4, maybe even 5 inches in your floor to chassis clearance.

(The big wheel looks like it can rotate clockwise all the way to where the little wheel starts)

Still want a top/bottom view:D

[DanielDTech]

I don't think it flips 180, as that CIM will have a hard time going through the mounting material. I think it's just aesthetically pleasing.

Indeed, it is aesthetically pleasing and it does not flip. But don't totally throw away the pivoting idea ;)

[DominickC]

Well, it's obvious you're itching to tell us more...so out with it!

[DanielDTech]

I hate to do this but here's a much larger image for everyone's viewing pleasure.

http://i.imgur.com/yzSjv.jpg

Also, I'm probably 100% wrong but it could possibly be that you have an 8WD narrowed down to a single module.

You are 100% wrong :) Thanks for posting the larger image.

[dodar]

Is this thing self-pivoting? Or do you just not have the pivoting setup in this model?

[DanielDTech]

Is this thing self-pivoting? Or do you just not have the pivoting setup in this model?

I don't have the pivoting setup on here... This is about 30% of the actual mechanism.

[sanddrag]

Automatic load balancing/switching between pushing force and higher speed? A CVT in there somewhere? Most of the device (as we know it so far) is shown in the render. I don't see any mystery really. I must be missing something here.

[ksafin]

I don't have the pivoting setup on here... This is about 30% of the actual mechanism.

Well that doesn't do us much justice xD

[DanielDTech]

Automatic load balancing/switching between pushing force and higher speed? A CVT in there somewhere? Most of the device is shown in the render. I don't see any mystery really. I must be missing something here.

You're missing nearly everything :P. Like I said, this is about 30% of the mechanism. It's not at all what you guys think it is.

[EricH]

This is certainly revolutionary, keep in mind that there is a HUGE concept that you're not seeing here.
Allow me to point out that if we can't see the concept (a third of it is missing), there is no way that we can tell if it's revolutionary or not. It may be that several teams have already done something--in that case it's NOT revolutionary unless there is something completely new.

What it is is it's a pivoting drivetrain section. If there is something else that is part of the drivetrain, that makes it different from any other pivoting drivetrain like an octocanum or the pivot-shifters of yesteryear, then it's either not put in or very well camouflaged.

Unless those two bolts at the near visibility side indicate modularity, that is, the ability to swap it out for another module in drivetrain, I think you need to raise the stakes significantly--say, pay $100 and hire whoever guesses correctly to decipher the game hint for you. (Incidentally, the modularity concept could run you into some trouble if you don't do it right--all modules go through inspection at the same time.)

[DanielDTech]

http://wap2p.com/sdbeta_images/uploaded/render5 modified.JPG


If anyone can correctly guess what this is, I solemnly swear that I will send you $15.00 on paypal before kickoff.

http://wap2p.com/sdbeta_images/uploaded/top view.jpg

Here's a top view for ya

[DanielDTech]

Allow me to point out that if we can't see the concept (a third of it is missing), there is no way that we can tell if it's revolutionary or not. It may be that several teams have already done something--in that case it's NOT revolutionary unless there is something completely new.

What it is is it's a pivoting drivetrain section. If there is something else that is part of the drivetrain, that makes it different from any other pivoting drivetrain like an octocanum or the pivot-shifters of yesteryear, then it's either not put in or very well camouflaged.

Unless those two bolts at the near visibility side indicate modularity, that is, the ability to swap it out for another module in drivetrain, I think you need to raise the stakes significantly--say, pay $100 and hire whoever guesses correctly to decipher the game hint for you. (Incidentally, the modularity concept could run you into some trouble if you don't do it right--all modules go through inspection at the same time.)

What I said was two thirds of it is missing. No modularity here. And I purposely took out the distinguishing part of the mechanism so that it wouldn't be completely obvious. There is definitely something completely new here, no doubt about it :)

[EricH]

What I said was two thirds of it is missing. No modularity here. And I purposely took out the distinguishing part of the mechanism so that it wouldn't be completely obvious. There is definitely something completely new here, no doubt about it :)

Raise the stakes, then. $1000 and payment to guess the game from the game hint. You're NOT going to get anybody guessing correctly if you only give us 1/3 of the mechanism. See also "game hint".

[Akash Rastogi]

What I said was two thirds of it is missing. No modularity here. And I purposely took out the distinguishing part of the mechanism so that it wouldn't be completely obvious. There is definitely something completely new here, no doubt about it :)

....

[Kevin Selavko]

While driving one way it uses one of the wheels, when it reverses the belt/wheel setup pivots around to go onto the other wheel with a different torque/speed.

[ratdude747]

I'm going to guess that part of it is weight reduction. It looks like it could be made very light.

It also looks very compact.

One thing that makes it unique is that this allows for both independent wheel drive AND two speeds/torques w/o the extreme cost/weight/space penalty that would result from one using 4 AM2/Supershifters. Even compared to using 4 dewalts (not as tall but much longer in the wheel axis), it looks very space efficient.

It also looks like it is meant to be mounted through a hole in a sheet metal base/pan. Perhaps even a sheet of plywood or other flat material. Maybe this is to simplify frame design? (Just a pan with 4 wheel holes?)

Or maybe it could be mounted in a lazy susan (the missing part mentioned) and used as a crab module? There have been 2 speed crab drives before (I know 1625's done it) but they all used non-independent drive systems (1625 used two drive shafts with miter gears to drive 6 wheels, 3 per shaft).

Another aspect I see is that the Cim is off center. Perhaps some sort of a counterweight?

Last, Perhaps another benefit of the design is that if you tossed a tread on the wheel (if it had such a tread), you'd already have a spare wheel you could toss in. Then again, this "automated spare tire" effect is also

[JVN]

"Simpsons did it."

Err... I mean... is it a dual wheel rocker where each wheel is a different speed with an automatic shifter mechanism?

[DanielDTech]

....

If i show the entire mechanism, there will be no guessing involved here... The point is to try to guess what that distinguishing component is. I don't believe anybody could do it, because of how out of the box it is. If it were easy, I wouldn't put $15 on it :P

[dodar]

out of the box

Its from Andymark.

[BigJ]

In this day and age, if you have something "truly revolutionary!!!!", you should be busy writing a patent for it and not bragging about it on a forum ;)

[Andrew Lawrence]

If i show the entire mechanism, there will be no guessing involved here... The point is to try to guess what that distinguishing component is. I don't believe anybody could do it, because of how out of the box it is. If it were easy, I wouldn't put $15 on it :P

Is the distinguishing component clearly visible on this photo (by clearly visible, I mean it is something we can see a decent portion of, it doesn't need to be shining in gold and covered in red paint)?

[DanielDTech]

Is the distinguishing component clearly visible on this photo (by clearly visible, I mean it is something we can see a decent portion of, it doesn't need to be shining in gold and covered in red paint)?

The distinguishing component is in fact completely removed from the assembly.

[connor.worley]

The distinguishing component is in fact completely removed from the assembly.

Suddenly, I'm missing the point of this thread.

[E_puello]

Is it a gearless 2 speed swerve module?

[Kevin Selavko]

If i show the entire mechanism, there will be no guessing involved here... The point is to try to guess what that distinguishing component is. I don't believe anybody could do it, because of how out of the box it is. If it were easy, I wouldn't put $15 on it :P

It goes on the outside of the robot haha

[dodar]

The distinguishing component is in fact completely removed from the assembly.

Are you seriously that slow? You want us to guess on what makes this different, and yet you took out what makes it different...

[DanielDTech]

Its from Andymark.

Nope :p

[Michael Blake]

Well it looks like it definitely flips in the direction of the larger wheel with the larger wheel traveling under to other side raising the small wheel way up in the air and flips the CIM completely to the other side...

IF NOT... just shoot me... LOL

[DanielDTech]

I'm going to guess that part of it is weight reduction. It looks like it could be made very light.

It also looks very compact.

One thing that makes it unique is that this allows for both independent wheel drive AND two speeds/torques w/o the extreme cost/weight/space penalty that would result from one using 4 AM2/Supershifters. Even compared to using 4 dewalts (not as tall but much longer in the wheel axis), it looks very space efficient.

It also looks like it is meant to be mounted through a hole in a sheet metal base/pan. Perhaps even a sheet of plywood or other flat material. Maybe this is to simplify frame design? (Just a pan with 4 wheel holes?)

Or maybe it could be mounted in a lazy susan (the missing part mentioned) and used as a crab module? There have been 2 speed crab drives before (I know 1625's done it) but they all used non-independent drive systems (1625 used two drive shafts with miter gears to drive 6 wheels, 3 per shaft).

Another aspect I see is that the Cim is off center. Perhaps some sort of a counterweight?

Last, Perhaps another benefit of the design is that if you tossed a tread on the wheel (if it had such a tread), you'd already have a spare wheel you could toss in. Then again, this "automated spare tire" effect is also

Very nice guesses! The unit is indeed very compact and light; it needs to be, since there will be more than one on the robot. But the big secret here is actually much simpler than any of these great educated guesses.

[DanielDTech]

Well is looks like it definitely flips in the direction of the larger wheel with the larger wheel traveling under to other side raising the small wheel way up in the air and flips the CIM completely to the other side...

IF NOT... just shoot me... LOL

It definitely doesn't pivot that much xD but I will not shoot you sir :(

[DanielDTech]

Suddenly, I'm missing the point of this thread.

To guess the purpose of this unfinished mechanism, or to guess what this crazy but simple other component is. That is as far as I go with giving hints... Lol

[DanielDTech]

"Simpsons did it."

Err... I mean... is it a dual wheel rocker where each wheel is a different speed with an automatic shifter mechanism?

In part, yes!

[Clinton Bolinger]

Missing 2/3 of the Design (http://cache.ohinternet.com/images/thumb/2/2d/Trollface_HD.png/618px-Trollface_HD.png)

-Clinton-

[DominickC]

Missing 2/3 of the Design (http://cache.ohinternet.com/images/thumb/2/2d/Trollface_HD.png/618px-Trollface_HD.png)

-Clinton-

This.

[roystur44]

The drive will lift up the chassis and be able to traverse a step or bump.

[JVN]

Missing 2/3 of the Design (http://cache.ohinternet.com/images/thumb/2/2d/Trollface_HD.png/618px-Trollface_HD.png)

-Clinton-

Video of it in action (http://www.youtube.com/watch?v=oHg5SJYRHA0).

[DanielDTech]

The drive will lift up the chassis and be able to traverse a step or bump.

Nope :P

[Siri]

For viewing convenience:
Renders: here (http://wap2p.com/sdbeta_images/uploaded/render5 modified.JPG) and here (http://wap2p.com/sdbeta_images/uploaded/top view.jpg)

DanielDTech in blue


The CIM motor isn't wasted at all
This is not only an interesting design, but a revolutionary one, in and beyond FRC

Yes, both wheels are simultaneously powered

...This does indeed have something to do with shifting, I'll tell you that. But there's something HUGE that you guys are missing...


A and B are wrong. C is partially correct!
A. Both "wheels" touch the ground at the same time
B. The "wheels" aren't actually for driving
C. The whole assembly pivots back and forth. This would work well for bumpy fields/ off road applications outside of FIRST


...yes, it's just the angle. Both wheels are actuated as a matter of fact.
While the guess that it is a shifting wheel, as it stands right now it doesn't appear that either of the wheels are actuated (Might just be the angle).


That is the closest guess yet. But again, you're missing something huge... The part that I think is pretty difficult for anyone to guess, otherwise I wouldn't put $15 bucks on it
So it's like Octocanum but switching between two traction wheels (for different speeds/wheelbases).


You are on track, but still very wrong. This is certainly revolutionary, keep in mind that there is a HUGE concept that you're not seeing here.
This is one quarter of a wheel-shifting drivetrain, where two different types of wheel can be changed at will, or used for climbing. Again, I don't think this is exactly revolutionary for FRC--similar things have been done on several occasions.


Indeed, it is aesthetically pleasing and it does not flip. But don't totally throw away the pivoting idea
I don't think it flips 180...


You are 100% wrong
I'm probably 100% wrong but it could possibly be that you have an 8WD narrowed down to a single module.


I don't have the pivoting setup on here... This is about 30% of the actual mechanism.
Is this thing self-pivoting? Or do you just not have the pivoting setup in this model?


You're missing nearly everything. Like I said, this is about 30% of the mechanism. It's not at all what you guys think it is.
Automatic load balancing/switching between pushing force and higher speed? A CVT in there somewhere? Most of the device is shown in the render. I don't see any mystery really. I must be missing something here.


Very nice guesses! The unit is indeed very compact and light; it needs to be, since there will be more than one on the robot. But the big secret here is actually much simpler than any of these great educated guesses.
It also looks like it is meant to be mounted through a hole in a sheet metal [or plywood] base/pan...Maybe this is to simplify frame design? (Just a pan with 4 wheel holes?) ... Or maybe it could be mounted in a lazy susan and used as a crab module? ... Another aspect I see is that the Cim is off center. Perhaps some sort of a counterweight? ... If you tossed a tread on the wheel, you'd already have a spare wheel you could toss in.


In part, yes!
A dual wheel rocker where each wheel is a different speed with an automatic shifter mechanism?
Editor's note: raise your hand if you're surprised this was JVN, that he got the first "yes" guess or that the first word in the post was "Simpsons"


It definitely doesn't pivot that much
Well is looks like it definitely flips in the direction of the larger wheel with the larger wheel traveling under to other side raising the small wheel way up in the air and flips the CIM completely to the other side...


Nope
The drive will lift up the chassis and be able to traverse a step or bump.





[/ImTooMethodical] I'll guess later.

[Akash Rastogi]

Is your mechanism inside the wheels? Internal gearing/anything?

*begins to lose interest*

[Littleboy]

The other 2/3s of it: the drivetrain.

[ksafin]

Hmm.. I'll take a crack at it..

Is this a mechanism for a robot?

[Michael Blake]

It definitely doesn't pivot that much xD but I will not shoot you sir :(

THANK YOU for not shooting me... I DO want to live... ;-)

SO, I believe you said JVN got it correct in what can actually be seen... "a dual wheel rocker where each wheel is a different speed with an automatic shifter mechanism"

Since I'm a pretend engineer please be gentle with me... it appears that part of the 2/3 missing is the mechanical actuator that causes the automatic shifting... like a vertical pneumatic cylinder that causes a pivot/change between the wheels, right?

IF NOT the case, I'm going to fire-up the TiVo and lose myself in THE WALKING DEAD and come back to this tomorrow...

[Harkirat Batoo]

Judging from the ratios I see, the wheels seem like they would be spinning at approximately the same speed, also the way the assembly is mounted suggests that it pivots, and the shape of the cut out of the mount suggests the smaller wheel can be raised significantly. In my opinion, this seems like a mechanism to either raise the chassis to over come an obstacle or a mechanism that allows a team to switch the configuration of their drive terrain during a mach, for example switching from a 4 wheel to an 8 wheel or 6 wheel to an 8 wheel or any other combination.

[apalrd]

I believe he's missing the encoder.

Don't forget your sensors.

[DanielDTech]

THANK YOU for not shooting me... I DO want to live... ;-)

SO, I believe you said JVN got it correct in what can actually be seen... "a dual wheel rocker where each wheel is a different speed with an automatic shifter mechanism"

Since I'm a pretend engineer please be gentle with me... it appears that part of the 2/3 missing is the mechanical actuator that causes the automatic shifting... like a vertical pneumatic cylinder that causes a pivot/change between the wheels, right?

IF NOT the case, I'm going to fire-up the TiVo and lose myself in THE WALKING DEAD and come back to this tomorrow...

Yes, there is a vertical cylinder that causes the pivot. But that's only another, let's say, 10% of the unit. So, I'll talk to you tomorrow! :P

[Cory]

"Hey guys, check out this super awesome thing I made, which is exactly what multiple teams made 8-9 years ago, with some revolutionary component missing. You have no possible way of guessing what is missing because I've given you absolutely no details, but I will string this thread along for the next month because it's fun to have lots of people wondering what my (not so) revolutionary design will be"

Does that about cover it?

[DanielDTech]

Judging from the ratios I see, the wheels seem like they would be spinning at approximately the same speed, also the way the assembly is mounted suggests that it pivots, and the shape of the cut out of the mount suggests the smaller wheel can be raised significantly. In my opinion, this seems like a mechanism to either raise the chassis to over come an obstacle or a mechanism that allows a team to switch the configuration of their drive terrain during a mach, for example switching from a 4 wheel to an 8 wheel or 6 wheel to an 8 wheel or any other combination.

No. Much more simpler and out of the box as that.

[Akash Rastogi]

"Hey guys, check out this super awesome thing I made..."

Does that about cover it?

http://www.youtube.com/watch?feature=player_detailpage&v=ufLzPqo1qfU#t=4s

[DanielDTech]

"Hey guys, check out this super awesome thing I made, which is exactly what multiple teams made 8-9 years ago, with some revolutionary component missing. You have no possible way of guessing what is missing because I've given you absolutely no details, but I will string this thread along for the next month because it's fun to have lots of people wondering what my (not so) revolutionary design will be"

Does that about cover it?

Hey guys, check out this extremely super awesome thing I made, which is not not exactly what multiple teams made 8-9 years ago, with some revolutionary and simple component missing. You have little way of guessing what is missing because I've given you very little details, but I will string this thread along for the next month because it's fun to have lots of people wondering what my extremely revolutionary drive mechanism will be.

I've made some edits, please review.

[Kevin Selavko]

Video of it in action (http://www.youtube.com/watch?v=oHg5SJYRHA0).

GAME HINT!

[BJC]

A couple thoughts on the design of what is revealed..

1. I don't think that putting this in a swerve module would be very smart. It is apparent that the small wheel can't be pivoted down until it reaches the center of the assembly. If this were on a pod that could turn the wheel touching the ground would literally be dragged sideways because the pod wouldn't pivot around the center of the wheel as is apparent in the top view. I'm ruling out swerve as this seems like it would probably be pretty suckish in that application. (Unless it only pivots when the big wheel is in the perfect position, again not that great a design.)

2. You only have mounting holes for this assembly on the wheel side which is presumably the outboard side of the chassis. This assembly either nests into another part of the chassis or else I would say that is also a design failure as the entire module would be in cantilever.

3. It appears that the axle that you are using to pivot on is live as it is modeled the same way as the wheel axles. If this is the case you could be doing something interesting where your drive motor also pivots the module, a second motor that pivots the module assists in powering the wheels (never mind), or if these are on a drivetrain with two to a side then the front and back can be chained together via this shaft. There is also very little holding those two halves together if all of those shafts are live. All I see is two standoffs by the motor. Based on the pictures I would try to get a standoff towards the big wheel side of the pivoting assembly.

4. If four of these are going on the Outer corners of a chassis I would be concerned about being able to turn. Your basically running a four wheel drive which picking up some wheels can't really help. Octocanium gets around this with omni/mec wheels. If this is the case your turning will basically stink. (unless you're wide) Unfortuantly, you can't just throw another wheel in the middle and chain off it because it won't switch ratios with the other wheels.

Based on what you've given us I think I see the general intent but I'm not sure that you've thought all the way through everything as it appears here.

I am not afraid.
Regards, Bryan

[MrTechCenter]

The rest of it pivots this one portion of it shown here in its entirety and this is used to make the whole bot pivot?

I'm probably not even close, I've never been on drivetrain team. ::ouch::

[Siri]

When you say "both wheels are actuated", it sounds as if you mean independently actuated--if so, along what line of action?

If not, what we have is a pivoting drivetrain module with two wheels at different gear ratios and diameters. The wheel are indeed drive wheels, powered simultaneously but contacting independently (meaning the treads shown contact the ground one at a time?) The special thing has something to do with changing the 3D position and/or its first derivative with respect to the chassis on which these units are mounted. I feel like it has something to do with being able to turn. As it stands, this seems like it would be really bad at turning--at least versus the work put into it--but it's definitely not swerve...
EDIT: Bryan beat me to #2 and 3 (though he did 3 way better than I did).

All that, and you know what bugs me? that little peg thing inside the triangular pivot axle support. What's up with that thing?

[Saberbot]

Just because no one's said it yet, I'm going to take a guess that this is for a ball drive.

Something similar to http://sphericaldrivesystem.com/ (http://http://sphericaldrivesystem.com/)

But on second thought, I dont' see how that could work without omni's for wheels.

If it's not a ball drive, I'm still going to guess that these wheels don't touch the carpet directly.

[DanielDTech]

A couple thoughts on the design of what is revealed..

1. I don't think that putting this in a swerve module would be very smart. It is apparent that the small wheel can't be pivoted down until it reaches the center of the assembly. If this were on a pod that could turn the wheel touching the ground would literally be dragged sideways because the pod wouldn't pivot around the center of the wheel as is apparent in the top view. I'm ruling out swerve as this seems like it would probably be pretty suckish in that application. (Unless it only pivots when the big wheel is in the perfect position, again not that great a design.)

2. You only have mounting holes for this assembly on the wheel side which is presumably the outboard side of the chassis. This assembly either nests into another part of the chassis or else I would say that is also a design failure as the entire module would be in cantilever.

3. It appears that the axle that you are using to pivot on is live as it is modeled the same way as the wheel axles. If this is the case you could be doing something interesting where your drive motor also pivots the module, a second motor that pivots the module assists in powering the wheels (never mind), or if these are on a drivetrain with two to a side then the front and back can be chained together via this shaft. There is also very little holding those two halves together if all of those shafts are live. All I see is two standoffs by the motor. Based on the pictures I would try to get a standoff towards the big wheel side of the pivoting assembly.

4. If these are going on the Outer corners of a chassis I would be concerned about being able to turn. Your basically running a four wheel drive which picking up some wheels can't really help. If this is the case your turning will basically stink. (unless you're wide) Unfortuantly, you can't just throw another wheel in the middle and chain off it because it won't switch ratios with the other wheels.

Based on what you've given us I think I see the general intent but I'm not sure that you've thought all the way through everything as it appears here.

I am not afraid.
Regards, Bryan

I can assure you that you definitely do not "see the general intent", unless that "general intent" is to drive the robot. None of you said is relevant to the overall idea of this mechanism.

As for the pivoting axis, what you see are spacers covering the actual moving axles. The middle axle is only used for, apart from holding that big pulley in the middle, mounting the pulley system to the oddly-shaped plate that you see.

[Brandon_L]

The power source for Doc Brown's Flux Capacitor

[Kevin Selavko]

Just because no one's said it yet, I'm going to take a guess that this is for a ball drive.

Something similar to http://sphericaldrivesystem.com/ (http://http://sphericaldrivesystem.com/)

But on second thought, I dont' see how that could work without omni's for wheels.

If it's not a ball drive, I'm still going to guess that these wheels don't touch the carpet directly.

What are the benefits of a ball drive?

[JosephC]

I think he created this as a joke; and it actually serves no purpose.

OR

We will all bow to this magnificent revolutionary on January 5th.

[timytamy]

I think someone suggested 180 degree but it seems like it is designed to pivot around maybe 90 degrees. Notice the cutout around the smaller wheel is large enough to fit the larger one as well. (although this may be for aesthetic/symmetrical reasons) What that would buy you I have no idea though. Maybe you can drive a second mechanism from the smaller wheel in an upright position?

Edit: nope
It definitely doesn't pivot that much
Well is looks like it definitely flips in the direction of the larger wheel with the larger wheel traveling under to other side raising the small wheel way up in the air and flips the CIM completely to the other side...

[Ed Law]

"Hey guys, check out this super awesome thing I made, which is exactly what multiple teams made 8-9 years ago, with some revolutionary component missing. You have no possible way of guessing what is missing because I've given you absolutely no details, but I will string this thread along for the next month because it's fun to have lots of people wondering what my (not so) revolutionary design will be"

Does that about cover it?

Cory, I am with you. I have absolutely no interest in this guessing game. Why am I posting? I have absolutely nothing better to do. This is a guy who just joined CD the day he posted this so this is his first post. Here is a 17 year old who is probably a senior this year and a team captain and this is his 4th year in FRC. Why is everybody else posting? Definitely not for the $15.

And why should I be afraid? Is it because if your robot is on the field, then mine should not even be used because yours is that awesome.

[dcarr]

I believe this post was intended to generate hype...but the response being generated isn't exactly what I'd call hype. It's just not the nature of CD. "Be afraid" -- really? This isn't really how folks share ideas in this community, but it's interesting. Good luck with the design, and I hope you're well into the fabrication and testing phase for your prototype if you have any plans of using this in 2013.

[James Tonthat]

"Hey guys, check out this super awesome thing I made, which is exactly what multiple teams made 8-9 years ago, with some revolutionary component missing. You have no possible way of guessing what is missing because I've given you absolutely no details, but I will string this thread along for the next month because it's fun to have lots of people wondering what my (not so) revolutionary design will be"

Does that about cover it?

Does anyone remember this thread (http://www.chiefdelphi.com/media/photos/36127)?

The solid 7071 billet frame, direct drive CIMs.

[R.C.]

This is silly, either show it or don't.

I"m afraid you'll be the partner that's not moving on our alliance...

-RC

[Gregor]

Does anyone remember this thread (http://www.chiefdelphi.com/media/photos/36127)?

The solid 7071 billet frame, direct drive CIMs.

I spent the last 20 minutes trying to find this thread to post here. You beat me to it :mad: :rolleyes:

[dcarr]

Does anyone remember this thread (http://www.chiefdelphi.com/media/photos/36127)?

The solid 7071 billet frame, direct drive CIMs.

Now this is a gem-filled read.

Edit: so this is where negative reputation on CD comes from :D

[MichaelBick]

Ok, because you said yes to JVN's automatic shifter idea, this is another guess.

There is some kind of mechanism that automatically pushes the wheel with more speed down. This causes you to have normal(high speed) operation most of the time. However when you reach an object that is either immovable or hard to move, the wheel will automatically pivot forward(overcoming the spring mechanism). This is because the wheel still wants to travel forward and it can by overcoming the spring. Eventually it pivots enough that the lower speed, high torque wheel touches the ground. Therefor you get the automatic shift into high torque. When you overcome the immovable/hard to move object the spring pushes the module back to "normal" and high speed mode ensues.

[Timz3082]

Am I the only one that realizes this won't work because there is not enough belt wrap on the 2nd stage pulley before the drive wheels? This needs to be fixed before implementation otherwise it will sit there spinning without actually transferring power to the drive wheels...

[Ryan Dognaux]

Chief Delphi is a place to showcase your ideas / designs and get feedback on them. Baiting people into trying to guess the function of your partially revealed design won't go over too well here.

Based on your previous season's robot's performance, I would recommend focusing your efforts on implementing simple functioning mechanisms that can effectively score points in the shortest amount of time. If this is a drive module, I don't see how this will make your robot score more points, unless the 2013 game challenge is drive on something really complicated - and it won't be.

[Akash Rastogi]

So I spoke to this student (I know others on 714), and he actually does legitimately have an idea he thinks is genuine and new.

So, this is not a troll thread. He is just now regretting posting this because he might not want to reveal what his idea actually is.

So....yeah.

Ease up on the kid though, he is not trying to troll. Not defending the way he presented this though.

Either you post your full design/idea, or you just leave it off the internet if you think it is that great. This is not how Chief Delphi works.

[Justin Montois]

Sorry, but i'm not afraid. I would be afraid if it was a robot, driving around, that you've gone through a competition season with and it showed to give you a distinct advantage. Right now, all I see is a CAD model with 1 CIM that was probably done pre-season which means you'll be going into 2013 with an untested drive. That's something that should scare you, not me ;)

[ksafin]

Does anyone remember this thread (http://www.chiefdelphi.com/media/photos/36127)?

The solid 7071 billet frame, direct drive CIMs.

Oh my god, this is great.

[DampRobot]

I'm quite ticked off by the OP. I hate to criticize a first day poster, but this is clearly a post designed only to call attention to his brilliance.

OP, here's my advice for you. Take a large helping of humble pie. There are lots of brilliant engineers and students who have been plugging away at the problem of drivetrains for over twenty years. If your "revolutionary" device is truly significant outside of FRC, that takes into account hundreds of times as many engineers for scores of times as long. I hate to break it to you, but someone has almost certainly come up with something very similar if not the same as your design.

In any case, showing us only 30% of the mechanism is no way to display your innovation, real or not. Call it a teaser if you want, but do not use it to parade your supposed superiority when we really do not have any chance to guess at whatever you have CADed.

Finally, in the unlikely event that you actually have come up with something brilliant, you should take heed to RC's comment. Unless you truly believe that you can pull this off during the season, don't. It sucks to have a stationary robot on the field, and this could well cause just that.

I know that I'm going to get some flack (read: negrep) for this post, but I feel like it is spot on. A good designer is not arrogant. In winning designs, egos take a back seat.

[efoote868]

What are the wheels contacting when they're not contacting the floor?

[Akash Rastogi]

Take a step back and relax folks. I've gotten the OP to post what he has been working on.

I have not seen what it is, so I am just as hopeful that he won't have his foot in his mouth as you are.

Should be up soon. Again, ease up on the kid, he did not mean to troll, he is just new to CD.

[s_forbes]

The central pivoting shaft is coaxial with the second stage idler pulley, and based on the bearing locations it looks like that shaft rotates with the pulleys. It's a self-destructing mechanism! :)

I'll be interested to see what the rest of the mechanism looks like, but from the renders we can only really tell that there are two wheels that go different speeds. Keep in mind that if these are indeed wheels for driving the robot, then the mechanism will have to be supporting a lot of weight. Make sure your parts are sized appropriately!

[DanielDTech]

Hey everyone, I'm really sorry for what this turned into. It wasn't my intention to seem like I'm trolling you guys. I'm completely new to this community; I made an account just to post the render. I wasn't even aware that it was so populated here at this time of year... Thankfully, Akash Rastogi found me on facebook and explained why this post was so controversial. Again, I didn't really know how things worked here at CD until Akash and others who posted here cleared it up for me.

I was hesitant to post the actual thing because we wanted it to be a surprise during the season, if the game even accommodates this drive, that is... But anyway, here's something to clear things up. Sorry about all this. I hope you guys can forgive me!

http://wap2p.com/sdbeta_images/uploaded/done.jpg

[Akash Rastogi]

Just because no one's said it yet, I'm going to take a guess that this is for a ball drive.

Something similar to http://sphericaldrivesystem.com/ (http://http://sphericaldrivesystem.com/)

But on second thought, I dont' see how that could work without omni's for wheels.

If it's not a ball drive, I'm still going to guess that these wheels don't touch the carpet directly.

Hey look! We have a winner!

[MichaelBick]

What advantage does this have over swerve?

[DanielDTech]

Just because no one's said it yet, I'm going to take a guess that this is for a ball drive.

Something similar to http://sphericaldrivesystem.com/ (http://http://sphericaldrivesystem.com/)

But on second thought, I dont' see how that could work without omni's for wheels.

If it's not a ball drive, I'm still going to guess that these wheels don't touch the carpet directly.

And of course, many props to Saberbot who was the only one to guess what it was. I did message him when he made the post to congratulate him and notify him that I would pay :P

[Saberbot]

Hey look! We have a winner!

Yes! Though I never would have guessed that the ball drive would be part of a swerve module. This is a really interesting idea, but I'm curious as to what advantages you see in this design compared to a regular swerve. Do you plan to be able to disengage the balls and have them behave as casters? I'm excited to see how this turns out.

[Joe G.]

First off, thank you!

Second off, sweet CAD!

Third, questions/constructive criticism (see how we can do that now? :p )

It appears that there is nothing that retains the ball vertically other than the robot's weight. I can assure you that even with a level field, you'll want to address this. The robot can be lifted up in collisions (not to mention carrying it on and off the field). If this is simply not yet modeled, disregard this comment.

What kind of bearings will you be using to support module rotation?

What kind of traction material will you use on the ball, and ball/roller interface? Fears of slip/low traction have always deterred me from ball drive.

The idea of shifting roller sizes on a ball drive for shifting is very cool, though I agree that as modeled, I don't see the advantage over a swerve with traditional dog sifters. I feel like this may have the potential to be more compact though, maybe by shifting the CIM down low, behind the ball. If there's an advantage I'm missing, please enlighten me though!

The initial module you posted looked like it had a lot of promise as a traditional wheel-switching shifting design. While not totally original, your design work was sound and compact. Maybe pursue this as well.

[DanielDTech]

First off, thank you!

Second off, sweet CAD!

Third, questions/constructive criticism (see how we can do that now? :p )

It appears that there is nothing that retains the ball vertically other than the robot's weight. I can assure you that even with a level field, you'll want to address this. The robot can be lifted up in collisions (not to mention carrying it on and off the field). If this is simply not yet modeled, disregard this comment.

What kind of bearings will you be using to support module rotation?

What kind of traction material will you use on the ball, and ball/roller interface? Fears of slip/low traction have always deterred me from ball drive.

The idea of shifting roller sizes on a ball drive for shifting is very cool, though I agree that as modeled, I don't see the advantage over a swerve with traditional dog sifters. I feel like this may have the potential to be more compact though, maybe by shifting the CIM down low, behind the ball. If there's an advantage I'm missing, please enlighten me though!

The initial module you posted looked like it had a lot of promise as a traditional wheel-switching shifting design. While not totally original, your design work was sound and compact. Maybe pursue this as well.

We are aware of the vertical ball retaining issue. This is not the completed unit. Like I said, I only posted the remainder of what needed to be posted so one could know what this is. We still have some design and innovation to do here, and we'll be vigorously working on this until kickoff.

Unfortunately I have to hit the sack because I have to wake up early tomorrow, but I'll back tomorrow to talk about the mechanism...

[Kevin Selavko]

How big each of the modules, and how many of these modules are you planing to have, 3 or 4? Do you think that there will be enough room for the full size of the swerves plus their turning motors/gears/belts? Another possibility is to use a mouseball kind of thing with omnis, this would also allow for strafing.
http://upload.wikimedia.org/wikipedia/commons/e/ed/Mouse-patents-englebart-rid.png
Also why are the wheels two different sizes?

[dcarr]

We are aware of the vertical ball retaining issue. This is not the completed unit. Like I said, I only posted the remainder of what needed to be posted so one could know what this is. We still have some design and innovation to do here, and we'll be vigorously working on this until kickoff.

Unfortunately I have to hit the sack because I have to wake up early tomorrow, but I'll back tomorrow to talk about the mechanism...

Make sure that you follow the rules when making your decision to use (or not use) your drivetrain in the 2013 season. With only 40 days to go (http://www.team3309.org/wp-content/uploads/2012/10/countdown.html), it may be pretty difficult to complete a prototype before kickoff. Something to think about.

From the 2012 Manual, section 4.1.4.


R18

Robot elements designed or created before the Kickoff presentation, including software, are not permitted.

Please note that this means that Fabricated items from Robots entered in previous FIRST competitions may not be used on Robots in the 2012 FRC. Before the formal start of the Robot Build Season, teams are encouraged to think as much as they please about their Robots. They may develop prototypes, create proof-of-concept models, and conduct design exercises. Teams may gather all the raw stock materials and COTS Components they want.

Example: A team designs and builds a two-speed shifting transmission during the fall as a training exercise. When designing their competition Robot, they utilize all the design principles they learned. To optimize the transmission design for their Robot, they improve the transmission gear ratios and reduce the size, and build two new transmissions, and place them on the Robot. All parts of this process are permitted activities.

Example: The same team realizes that the transmission designed and built in the fall perfectly fits their need for a transmission to drive the Robot arm. They build an exact copy of the transmission from the original design plans, and bolt it to the Robot. This would be prohibited, as the transmission – although fabricated during the competition season – was built from detailed designs developed prior to Kick-off.

Example: A team developed an omni-directional drive system for the 2011 competition. Over the summer of 2011 they refined and improved the control software (written in C) to add more precision and capabilities. They decided to use a similar system for the 2012 competition. They copied large sections of unmodified code over into the control software of the new Robot (also written in C). This would be a violation of the schedule constraint, and would not be allowed.

Example: The same team decides to use the LabVIEW as their software environment for 2012. Following kickoff, they use the previously-developed C code as a reference for the algorithms and calculations required to implement their omni-directional control solution. Because they developed new LabView code as they ported over their algorithms, this would be permitted.

Example: A different team develops a similar solution during the fall, and plans to use the developed software on their competition Robot. After completing the software, they post it in a generally accessible public forum and make the code available to all teams. Because they have made their software generally available (per the definition of COTS, it is considered COTS software and they can use it on their Robot).

[sanddrag]

The Technokats did a ball drive in 2003, and I think Andy Baker went on to patent the idea. There's a thread on it somewhere around here.

[Gregor]

http://www.chiefdelphi.com/forums/showthread.php?t=18772&highlight=ball+drive

[dcarr]

The Technokats did a ball drive in 2003, and I think Andy Baker went on to patent the idea. There's a thread on it somewhere around here.

A quick Google search uncovers a couple threads and videos including balancing on the 2012 bridge :)

As awesome as this is, I would be interested in a breakdown of the pros/cons of choosing something like this versus a well-implemented swerve (a la 1717, 973, etc.). I'm not seeing any benefits, but I have only a cursory understanding of drivetrains at the moment.

[bhumudar]

Let me start by saying that I have also spoke to Daniel about etiquette on the forms and am happy to see his attempt at rectifying the situation. With that being said this design is by no means a finished product. We are still hard at work picking out all the little details so that we can have a smooth running drive-train for this year. In addition to that, we are not yet certain if this will even be the drive-train system that we will be using for this years game, considering we know very little to nothing about what it really is. Finally, as much as I did not want to disclose so much detail on the design we have so far this early on I suppose the design is now up for discussion. The other half of the magic is in the programming anyways ;) So have at it!!!

I'm excited to see everyone at kick-off, see you then!

[Siri]

I'll try to limit it to 5 questions:
1. What's the advantage of this versus standard swerve?
2. What language are you programming in, and how far have you gotten?
3. What cylinder are you using, and how is it mounted? What's the normal force between the rollers and the ball, and what're the CoFs?
4. What's the total module weight and how does the chassis interface work?
5. What experience will you have with this by kickoff? As it stands, I have to echo R.C.'s comment. I've known--and have been--a first-year swerve team. In all honesty, it looks like you're setting yourself and your alliances up for trouble jumping in on January 5th. Good luck either way, though.

[Peyton Yeung]

This past summer I revived team 45's ball drive and it has seemingly lack-luster results. While it is much simpler than your current design it still doesn't perform as well as some swerve drives I've seen and driven. If you can get it working more power to you. If you want, PM me and I can send you more pictures of our 2003 ball drive robot and give you a good list of pros and cons.

[bhumudar]

1. There are two advantages that we have seen so far. The first is a serious weight reduction as we don't need AM shifters. Also the ball will be made of carbon fiber wrapped in some undecided traction material. We also get a bit more friction if we were lets say trying to be pushed by another robot. This is due to the fact that we can put the driving wheels perpendicular to the incoming force, thus allowing the friction between the ground and the ball as well as the driving wheel and the ball. The second advantage is that we can easily disengauge the ball completely and use it as a "castor wheel".

2. LabVIEW. We have written some preliminary algorithms for the basic driving. We are now working on automating some maneuvers.

3.We still haven't decided on the exact cylinder, but will most likely use the tiny cylinder in the KOP (I can't remember the bore size). It will be mounted on a pivot point at an angle from the floor to the right of the big drive wheel.

4. We are aiming at less than 3 lbs (without including the CIM). This will depend on what materials we use (carbon fiber, aluminum, titanium). It will be a modular plugin to the chassis.

5. I have taken this into consideration, so in response, we will only be using this system if it is successfully running in a fair amount of time.

[Chris is me]

It looks like this ball is only powered on one axis. In that case, why a ball and not a wheel?

[Siri]

Cool! Thanks. Followups:

1A. I'm missing how you get "more friction". Isn't the first place you slip the only one that matters? I guess I'm not understanding what you intend to do (in part because of Chris's question).

1B. What's the benefit of turning it into an caster wheel in this setup?

4. Wow, 3 pounds? Keeping that in-cost is definitely impressive. What's the ball diameter?

[bhumudar]

Again due to the weight reduction advantage. The module its self is able to rotate 360 degrees to give the swerve effect. Also this whole project is a way for us to satisfy our engineering curiosity and out of the box thinking.

[bhumudar]

Siri,

1. You are correct in that the first place that you lose friction is the only one that matters, but since there are multiple contact points, each one adds to the total friction available. Lets suppose you see an incoming robot front the right of our robot, we would turn the wheels so that they face front to back (perpendicular to the incoming force).

2. It would simply be used as a built-in neutral position which may or not help with this years game.

3. I believe the diameter is about 4 inches.

[JesseK]

Maybe I'm a cynic, but until this design gets the Aren Hill Seal of Approval (or at least his thoughts), I dunno that I'd put it on the field during the season. Aren has more experience with different/non-standard swerve designs than any single person on these forums. OP, I'd message him specifically if I were you.

Also, post the overarching design as a Photo to get more/better feedback -- the veterans on these forums tend to write these types of threads off as more chatter when sifting through the noise. "Be VERY Afraid" will not get you a whole lot of constructive feedback on a technical design.

Presentation aside, it definitely looks interesting.

[Andrew Remmers]

Beautiful CAD! But the concept I'm a bit skeptical about. What happens if your robot is hit really hard? Can the ball become dislodged? It looks like you are relying on gravity and the wieght of the robot to actually hold it onto the ball. What if your Robot CG is higher and your drive ball becomes a part of the field accidentally?

Thats what I see.

- Andrew

[MichaelBick]

1) I can see a couple of problems here. First of all I'm not sure you can get as much traction on that ball as you would wish. The common matertial that I would think of using to cover the ball is roughtop. However roughtop's performance on carbet is directly related to how much tread is touching the carpet. Second the locking system that you described can be done with a regular swerve. However with a regular swerve it is mechanically impossible for the wheel to roll, so you will have a greater resistance to being pushed. Also this whole setup is less efficient. Lastly you usually don't want castor wheels. In this setup specifically you will lose motor power. However I could see them being useful maybe on the bridge this past year.

4) A pound or two more it seems like you could do mini modules like 1625 did. This setup would be much more efficient than your current one, and for the performance gain it would probably be worth the weight. Try getting modules as small as possible. I have done it and it is a very interesting design challenge.

[Brandon Holley]

1. You are correct in that the first place that you lose friction is the only one that matters, but since there are multiple contact points, each one adds to the total friction available. Lets suppose you see an incoming robot front the right of our robot, we would turn the wheels so that they face front to back (perpendicular to the incoming force).


I think the way you are wording this statement is misleading. Siri's statement that you reiterated is very important- whatever slips first is the limiting factor.

I believe I understand what you are saying, that by moving the wheels perpendicular to the incoming force, you are using the traction of the ball and floor as your traction limit as opposed to the traction limit on the wheels against the ball. What is hanging me up is the part where you say "each one adds to the total friction available". This is not a summation, your maximum theoretical resistance to pushing (or traction) will be limited by the ball's traction with the floor.

-Brando

[dodar]

I think the way you are wording this statement is misleading. Siri's statement that you reiterated is very important- whatever slips first is the limiting factor.

I believe I understand what you are saying, that by moving the wheels perpendicular to the incoming force, you are using the traction of the ball and floor as your traction limit as opposed to the traction limit on the wheels against the ball. What is hanging me up is the part where you say "each one adds to the total friction available". This is not a summation, your maximum theoretical resistance to pushing (or traction) will be limited by the ball's traction with the floor.

-Brando

Wouldn't it then be the: ball traction - wheel traction = Max. Theoretical Traction.

[Saberbot]

Doesn't a sphere give you a disadvantage as far as friction is concerned?

In a perfect spere only one point would be tangent to the ground.

In a wheel, the entire width of the tread is touching the ground.

Am I missing something?

[MichaelBick]

Doesn't a sphere give you a disadvantage as far as friction is concerned?

In a perfect spere only one point would be tangent to the ground.

In a wheel, the entire width of the tread is touching the ground.

Am I missing something?

Regularly your traction is based on weight and COF. However with roughtop the tread locks into the carpet so this is ture.

[Michael Blake]

I would not have guessed this... thought it was a re-imagining of the Nonadrive corner module... though, I'm a pretend engineer and THAT'S my excuse...

QUESTION: I don't see anything that leads to structure that holds the chassis up? Where's the shaft that this spins around on that will support the weight of the robot?

I'm assuming the shaft will be on the top-side of what's shown so far... or, are you going with a "Lazy Susan" on top with this fastened underneath and attached with standoffs (like the large gear below)?

[Tom Line]

Hrmp. My delete button is broken.

[Siri]

The module its self is able to rotate 360 degrees to give the swerve effect.What's the full weight of the unit (with swerve)? And what leads you to believe the ball system will be lighter than using wheel?

You are correct in that the first place that you lose friction is the only one that matters, but since there are multiple contact points, each one adds to the total friction available. Lets suppose you see an incoming robot front the right of our robot, we would turn the wheels so that they face front to back (perpendicular to the incoming force).Do you propose that the system will begin slipping between the ball and the rollers or between the ball and the floor? (Why?) I think Brandon and I are both stuck on how aligning the rollers increases this threshold vis a vis a system that doesn't use a frictional drive for steering (i.e. a belt, chain or gear swerve).

And listen to Jesse; you really want to talk to Aren.


Tom: secret's out (http://www.chiefdelphi.com/forums/showpost.php?p=1196044&postcount=106). OP should probably edit the original post.

[Madison]

These threads are interesting -- and we don't see many of them around anymore, unfortunately -- because they document someone's effort to make a better mousetrap. What becomes clear as the discussion progresses is that there are still lots of folks that still have a lot to learn about the forces at work and considerations we face while making decisions about how a mechanism will work. I might've appreciated this a bit more if there were not 6+ pages of attention-seeking.

As shown, this almost absolutely will not work. It appears to offer no advantage over swerve drive but has several disadvantages that swerve does not suffer. I'd like to see some math justifying ANY of the claims y'all have made re: friction, pneumatic cylinder size, etc.

[Ryan Dognaux]

Lets suppose you see an incoming robot front the right of our robot, we would turn the wheels so that they face front to back (perpendicular to the incoming force).

Maybe I'm not thinking clearly, but why would you ever want to do this with the drive module you're intending to build? If anything with this drive you would want to avoid robot to robot contact if at all possible. I just see this probably losing any pushing matches with a standard 4 CIM 6WD setup, but would love to be proven wrong.

[sanddrag]

I'm curious what particular product or material he intends to use for the ball.

You might be interested in this: http://www.autoblog.com/2012/09/19/spherical-drive-motorcycle-being-developed-by-engineering-studen/

[BJC]

Hey there,

I see that this idea/module was pretty much completely picked apart and shown to be a horrible idea so I won't bother with telling you any of that. Hopefully, you’re not too disappointed that the module/idea that you probably spent a long time designing isn't as great as you thought it was.

I just wanted to take a second to encourage you to continue thinking, inventing, and innovating. The people on this forum just want your team to be successful. Posting your designs on the forum is a gutsy move as any new design will be dismembered by many smart people. It is also one of the best things you can do as you get free constructive criticism from a bunch of smart people that have collective experience beyond what you could ever hope to gather by yourself.

Anyways, I hope you can take this away as a positive experience. If you hadn't posted on here and instead just went ahead and built your drivetrain for the 2013 season you would almost certainly be fighting your design the entire season and had a not-fun-at-all experience as a result.

Good Luck in your 2013 season and your future design endeavors.

Kind Regards, Bryan

[BrendanB]

Wow I was not expecting to see that when I logged in today! :ahh:

I do agree that this drive isn't the best choice for FRC application unless the game changed to limit robot to robot contact and it wasn't so complex. Every drive has its weaknesses.

I do want to congratulate you for thinking outside the box. Too many of us get caught up in trying to keep up with the elite teams by making swerves, WCDs, octocanums, etc without really trying to come up with the something new or reinvent the wheel er... ball! Great model and design! Keep it up! :)

I would encourage to keep working on this model. Maybe you could build one as an off-season/fun build project! You could even rework your wheel choice and have a sweet module for octocanum by switching one wheel for a mecanum!

To everyone else. Is the design far fetched? Maybe. Are there some problems in the design? Possibly. But let's keep this as a positive discussion. Someone put a lot of time and effort into designing and modeling something cool and by keeping positive discussions going we encourage more designs to come forth instead of lurking on members' desktops in fear that we will tear it apart in our posts. Every year I dream of 8wd WCD swerves! :rolleyes:

Nice work and good luck in your future designs!
Brendan

[EricH]

I would say that if the module were used in FRC competition, you'd probably run into some difficulties in steering and traction, as noted already. (Aside from the potential for terrain popping the ball out if there wasn't a retaining device--I didn't see one in the model.)

But... I would suggest building one as an offseason project if you don't do it in season. Build a T-shirt cannon (or other promo device) on top of it. Offseason demobots need a "COOL!" factor, which I think this has--especially if it works as advertised.

[Garret]

I spend my free time making crazy designs like this in CAD, as such I enjoy seeing these designs whenever I get the chance.

From my personal experience. It always sucks when people criticize a design a lot. I would advise you to hear it as trying to help, rather than that the design is bad or not worth pursuing. You should still listen to most of what has been said, but I think giving up on this design would be a real shame. I know of at least one instance where a company shot down an idea in a brainstorming session, and a number of years later made that one idea the most important distinguishing feature of their technology (and it still is to this day).

In my opinion FIRST would be much cooler if more teams were trying these crazy new designs, rather than just making another WCD and doing stuff purely because "its what the Einstein teams do". I hate hearing people say that a team shouldn't do something because no teams on Einstein used it. Reasons a team should use or not use those designs would be that they are what works for that team and because they would be the most effective for that challenge, not because some other really good team has done it or, the other extreme, no one else has done it.

These types of out-of-the-box designs are always fun/inspirational to design and look at. I found this design inspirational and it is a beautiful CAD model.

[Cory]

In my opinion FIRST would be much cooler if more teams were trying these crazy new designs, rather than just making another WCD and doing stuff purely because "its what the Einstein teams do". I hate hearing people say that a team shouldn't do something because no teams on Einstein used it. Reasons a team should use those designs would be that they are what works for that team and because they would be the most effective for that challenge, not because some other really good team has done it so let's do what they do.

There's nothing wrong with investigating "crazy new designs" from a learning perspective, the reality is just that in real life when you get a job you don't innovate for the sake of innovating, you only do it when existing solutions do not provide the solution to your problem.

Innovative is also not synonymous with good, or indicative of sound engineering. Both are important.

[rcmolloy]

There's nothing wrong with investigating "crazy new designs" from a learning perspective, the reality is just that in real life when you get a job you don't innovate for the sake of innovating, you only do it when existing solutions do not provide the solution to your problem.

Innovative is also not synonymous with good, or indicative of sound engineering. Both are important.

This has everything wrapped up in a nutshell regarding this entire thread.

Also to the original poster of the other quote, these teams aren't doing crazy designs because of their limitations and just the amount of work and effort required to realistically do some of them. Even though the crazy and novel ideas are very cool, they usually aren't the best practical ideas that you would like to go with.

[Garret]

There's nothing wrong with investigating "crazy new designs" from a learning perspective, the reality is just that in real life when you get a job you don't innovate for the sake of innovating, you only do it when existing solutions do not provide the solution to your problem.

Innovative is also not synonymous with good, or indicative of sound engineering. Both are important.

I agree with you completely, I was more saying that people should use (or not use) designs for the right reasons.

[Madison]

Okay, I have a bit more time now that I'm not at work and can list some of the questions I have about how this would work and what the benefits are.

Years ago, I was able to receive a lot of fantastic feedback from engineers on this site, so there's definitely merit to posting ideas and soliciting feedback. That should continue, but a bit of humility goes a long way.

Questions/Concerns --

0. What problems were you trying to solve when making this design? What were the criteria you used to guide your decision making process and how did each of this model's elements satisfy that criteria?

1. Do you intend for the sphere to slip sideways against either driving roller? If not, no part of the sphere that isn't touched by a roller will ever contact the ground, so why use a sphere at all? If yes, the maximum possible force of friction between the sphere and the driving rollers must be less than the maximum force of friction between the roller and the carpet; this sacrifices available pushing force, putting your robot at a disadvantage in pushing matches.

2. The sphere is driven by a roller using friction. The available force of friction will be determined by the pneumatic cylinder pushing the roller against the sphere. You can use leverage here to make a smaller cylinder provide force that nears or exceeds your practical maximum possible friction force as determined by the coefficient of friction between your roller and sphere/sphere and carpet, but in all cases, the maximum friction force the robot can exert on the ground will be dictated by the sphere/carpet interaction.

3. When a roller is being pressed onto the surface of the sphere, because there is currently nothing shown to retain the ball from moving away from the drive rollers and ball casters, your mechanism will push the robot away from the sphere, unseating it from within the four ball casters. You will now be riding only on the thin interface between your drive roller and the sphere.
Driving forward or backward will cause the sphere to shift in the opposite direction. Any sideways motion will cause the sphere to slide sideways off the driven roller and, for lack of a better explanation, wedge itself into place between the drive rollers and two of the ball casters. You may not be able to recover from this condition except by going to a middle position that removes both rollers. The condition will repeat anytime you try to drive, however. You absolutely have to capture the sphere so that it cannot move vertically independently of the rest of the module for this to have ANY shot at working at all.

There are a lot of problems here and I think that, if you worked through them, you'd end up at a swerve module.

[Akash Rastogi]

What's the full weight of the unit (with swerve)? And what leads you to believe the ball system will be lighter than using wheel?


Going to add to this: Why not try to further the efficiency of existing designs? If you have the capabilities to create a carbon fiber sphere correctly and within budget, why not try to mold your own wheels or other parts out of carbon fiber? (doing either one properly is pretty difficult from what I've learned in materials classes... http://helix.gatech.edu/classes/ME4182/1998Q4/Webs/super_g/deliverables/finalpaper.html)

[cmrnpizzo14]

First off, awesome concept. I really can't believe that I just spent 30 minutes reading through all of this, but it is a fantastic concept. Your presentation of it leaves much to be desired ;) but it's forgiven (imho).

Secondly, I have a question about the maintenance of it. If you have the balls held in place by something other than the weight of the robot (which I heavily advise!) replacing a ball will be difficult. Hopefully you will never need to actually replace one, but just in case....

Also, the actual balls you will use will possibly be carbon fiber? Carbon fiber is cool, that is not deniable. However, how will you make them to resist impact. I am no expert on carbon fiber by any stretch of the imagination, but I do know that it is fragile. In addition, your wheels are what takes the most weight on the robot. I understand that a sphere is ideal for force distribution, but I still would be worried about damage to your balls.

Lastly, if you get this to work in any way at all, please put up some sort of video of it driving. This would be amazing to see work, even if it was not in a competition. Please keep us updated!

[RedLeader342]

it looks like the small one could be a build up wheel to the big one which then shoots a foam basketball.

[Andrew Lawrence]

Read through the thread, Redleader. The final design was released a long yime ago.

[seg9585]

Just wanted to say that I read every thread in this post for the past half hour, and I'm unequivocally impressed with both the innovative design efforts of the students and mentors in FRC, as well as the level of technical expertise and quality discussion on CD.

Daniel and the rest of Team 714, I think the design is impressive, the modeling is fantastic, and overall you deserve a ton of credit for presenting your idea and working through the constructive criticism on this board. Regardless or whether this is the most efficient design out there or not specifically for the application of an FRC drivetrain, I truly hope to see you follow through and make a finished product out of it (and post videos!!) ... because this is what innovation is all about. After all, FRC is the best place to innovate -- you may not get as many opportunities to do so in the workforce (in the corporate world, time is money, and innovation is time consuming).

FIRST is awesome!

[MentorPrice]

It looks like it can either be a duel powered wheel assembly either used for stabilization or for use as a shooter to regulate the distance the projectile will travel?

[CalTran]

It looks like it can either be a duel powered wheel assembly either used for stabilization or for use as a shooter to regulate the distance the projectile will travel?

Again, read the thread. It was officially announced, complete with full CAD of what it actually is.

[toastnbacon]

That is beautiful! You'll have to let us know how well it works. And tell your programmers I'm praying for them... :yikes:

[Connor1868]

Is this wheel device for driving over a Frisbee? One wheel up off the ground to get over the Frisbee and a second wheel to stay on the ground.

[Siri]

Is this wheel device for driving over a Frisbee? One wheel up off the ground to get over the Frisbee and a second wheel to stay on the ground.This was published before kickoff and was revealed here (http://www.chiefdelphi.com/forums/showthread.php?p=1196044#post1196044).

Might a mod change the thread title or close it? This seems to be happening a lot...

[MyNameIsPaul]

I think it's a bluff