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-   -   pic: Team 148 - 2011 - Raptor (http://www.chiefdelphi.com/forums/showthread.php?t=92368)

Meredith Novak 24-02-2011 23:08

Re: pic: Team 148 - 2011 - Raptor
 
Awesome robot, 'Ranglers. Can't wait to see it in person next week!!!

We will be up against a Raptor and a Dragon...and we look like a duck...a mighty duck...

JVN 25-02-2011 13:40

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JVN (Post 1030614)
After receiving a number of requests in response to this post, I decided to highlight some of the subtle parts of this year's design on my blog as part of an "Inside Raptor" series.

Another in this series, discussing the one of the reasons we chose to build the design we did, and some more detail on the wrist joint:
http://blog.iamjvn.com/2011/02/insid...st-joints.html

-John

Madison 25-02-2011 14:04

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JVN (Post 1031297)
Another in this series, discussing the one of the reasons we chose to build the design we did, and some more detail on the wrist joint:
http://blog.iamjvn.com/2011/02/insid...st-joints.html

-John

John -- thanks for taking the time to do this series of blog posts. I often wonder if the way I conceptualize and design things is "right," or if I'm off in my own corner of the world somewhere doing weird things that are crazy.

The manner y'all use to extend the upper part of your four-bar is exactly like something I'd conceptualized a few years ago after I was unhappy with the telescoping mechanism on our 2005 robot. It's awesome to see that someone else had a similar idea and even better to see it implemented so well.

JVN 26-02-2011 17:14

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JVN (Post 1030614)
After receiving a number of requests in response to this post, I decided to highlight some of the subtle parts of this year's design on my blog as part of an "Inside Raptor" series.

Here is another in this series describing our use of aluminum plate gears this season:

http://blog.iamjvn.com/2011/02/insid...ate-gears.html

-John

Cory 26-02-2011 17:56

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JVN (Post 1031844)
Here is another in this series describing our use of aluminum plate gears this season:

http://blog.iamjvn.com/2011/02/insid...ate-gears.html

-John

John,

I'm curious how you avoid misalignment of the teeth relative to each plate after assembly. Do you bolt both plates together and then cut the teeth? Do you use pins to align them and then clamp them with bolts? is it just "good enough" that you can bolt them together without any alignment aids?

sgreco 26-02-2011 18:29

Re: pic: Team 148 - 2011 - Raptor
 
I'm curious as to why you chose to stack plates instead of just cutting a thicker plate? I can understand if it was really thick for cost purposes, like over a half an inch, but wouldn't it be easier for a 3/8 piece to just cut one from a thicker piece of metal? I suppose if you're laser cutting then thicker aluminum isn't an option on all lasers because of aluminum's reflective properties.

I've also always been curious, are your parts lasered of waterjetted?

JVN 26-02-2011 18:56

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Cory (Post 1031857)
John,

I'm curious how you avoid misalignment of the teeth relative to each plate after assembly. Do you bolt both plates together and then cut the teeth? Do you use pins to align them and then clamp them with bolts? is it just "good enough" that you can bolt them together without any alignment aids?

It is just "good enough."

We align the plates (using a mating gear + eyeballs) and then clamp them with c-clamps before riveting.

These are aluminum gears, and we figured they'd wear in happy.

Again -- we were surprised how well this worked. We were expecting more hassle... but... it just works.

-John

JVN 26-02-2011 18:57

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by sgreco (Post 1031864)
I'm curious as to why you chose to stack plates instead of just cutting a thicker plate? I can understand if it was really thick for cost purposes, like over a half an inch, but wouldn't it be easier for a 3/8 piece to just cut one from a thicker piece of metal? I suppose if you're laser cutting then thicker aluminum isn't an option on all lasers because of aluminum's reflective properties.

I've also always been curious, are your parts lasered of waterjetted?

Our parts are lasered. We use 1/8" plates stacked instead of thicker plates for two main reasons:

1. The laser does have some "blow out" which will affect the tooth profile in thicker materials.

2. Our shop stocks 1/8" 6061 aluminum, so we can get it without a special order. When I'm trying to get 24 hours turns, I try not to make our shop do anything they don't normally do for production.

-John

s_forbes 26-02-2011 22:59

Re: pic: Team 148 - 2011 - Raptor
 
Cool stuff, John!

Maybe you guys need to start up a Robowranglers R&D division to test more neat ideas like this... you can attempt all kinds of weird projects that would normally be foolish to try during a build season*. Though it sounds like your offseason work already accomplishes this. :)


*cough* walking robot *cough* *cough*

LBseale 27-02-2011 11:32

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JVN (Post 1028544)
CG isn't reason enough?

One other reason is my hatred of chain, but mainly for CG reasons.
I would also suspect this is lighter than an equivalent low-gearbox + chain + sprocket...

Plus... c'mon... DOUBLE FOURBAR!

If you dislike chain so much, why did you choose to chain together your omni-wheels and traction wheels? From your models it looks like you have enough CAD experience to space and use timing belts. SolidWorks (at least, maybe Inventor does too) comes with a tool for calculating belt lengths that's very handy. Belts are quieter and don't need tensioning.

JVN 27-02-2011 11:59

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by LBseale (Post 1032116)
If you dislike chain so much, why did you choose to chain together your omni-wheels and traction wheels? From your models it looks like you have enough CAD experience to space and use timing belts. SolidWorks (at least, maybe Inventor does too) comes with a tool for calculating belt lengths that's very handy. Belts are quieter and don't need tensioning.

Maybe next year.

We dislike chains that we need to worry about. This low-load application is pretty happy the way it is.

sdcantrell56 27-02-2011 12:02

Re: pic: Team 148 - 2011 - Raptor
 
We've used laser cut gears in manipulators before when a small range of motion was desired but Ive never thought about using them in a drive application. Be sure to post up at the end of the season about any wear issues you encountered because otherwise it is a very simple solution to custom gears. I'll be sure to check them out at alamo.

JaneYoung 27-02-2011 12:22

Re: pic: Team 148 - 2011 - Raptor
 
I wonder if there is any maximum allowance of people/teams per pit. Looks like 148 is going have a crowd. Non-stop. :) Again.

Ian Curtis 27-02-2011 13:18

Re: pic: Team 148 - 2011 - Raptor
 
How do you generate the tooth profiles? Does IFI just have a piece of software that spits it out, do you do it by hand :ahh: , or is there a handy SW feature that I've missed that does it for you?

MagiChau 27-02-2011 13:28

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JaneYoung (Post 1032131)
I wonder if there is any maximum allowance of people/teams per pit. Looks like 148 is going have a crowd. Non-stop. :) Again.

Well 148 would be nagged about the safety issue of too much people crowding your pit.

JaneYoung 27-02-2011 13:41

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by MagiChau (Post 1032150)
Well 148 would be nagged about the safety issue of too much people crowding your pit.

Actually, it's always a pleasure to notice how planning committees work to make the pits efficient and, at the same time, a showcase for teams like 148 and 118, allowing space where there is some to be had. It's also nice when rookies are placed between veteran teams or are placed in an area together where they can be accessed and helped easily by veteran teams and volunteers who will help. Teams like 148 are very aware of their draw and they work hard not to infringe on other teams' space. I've seen it on Championship level and Regional level. It's also the job of the pit volunteers to help keep things orderly and running smoothly.

JVN 27-02-2011 14:00

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Ian Curtis (Post 1032145)
How do you generate the tooth profiles? Does IFI just have a piece of software that spits it out, do you do it by hand :ahh: , or is there a handy SW feature that I've missed that does it for you?

There are lots of ways to do this. Some of my favs:

1. Pull out your handy Machinist's Handbook and sketch the tooth profile by hand.

2. Buy one of those gear profile generation programs and get it to spit it out for you.

3. Download the gear from somewhere online. bostongear.com has all their gears available online.

For this year's robot we used option 3. I downloaded the gear I wanted from Boston gear, then traced over the tooth in Solidworks (eliminating splines with simple arcs, so it would import cleaner into our laser cutter's NC program). I grabbed this sketch, dropped it into a new sheetmetal part and away we went...

-John

Tristan Lall 27-02-2011 16:17

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JVN (Post 1032168)
There are lots of ways to do this. Some of my favs:

1. Pull out your handy Machinist's Handbook and sketch the tooth profile by hand.

2. Buy one of those gear profile generation programs and get it to spit it out for you.

3. Download the gear from somewhere online. bostongear.com has all their gears available online.

For this year's robot we used option 3. I downloaded the gear I wanted from Boston gear, then traced over the tooth in Solidworks (eliminating splines with simple arcs, so it would import cleaner into our laser cutter's NC program). I grabbed this sketch, dropped it into a new sheetmetal part and away we went...

-John

A few more options:
  1. It's surprisingly easy to generate a real involute using equations; this and this explain how to do it in Pro/E (but any CAD software ought to be able to do the same).
  2. If you can make do with an approximation instead, either follow the second method in the link above, or get GearGen (I think it's shareware*) from here or here. (It's a DOS program, so the interface might be a little unfamiliar nowadays....) This makes a sort of segmented polyline when exporting, with arcs that (as near as I can determine) are approximate. But thanks to modern, fast computers, you can create an arbitrarily large gear and scale it down to whatever degree of precision you need—so this isn't a problem so long as your CAM software won't choke on the geometry. (Note that all of those facets will make 3-D CAD really slow to regenerate; use the equation in that case, or just approximate it for visual purposes.)

*Does anyone even use that term anymore?

JVN 28-02-2011 10:53

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JVN (Post 1030614)
After receiving a number of requests in response to this post, I decided to highlight some of the subtle parts of this year's design on my blog as part of an "Inside Raptor" series.

Another from this series which highlights the Drive Module layout.
http://blog.iamjvn.com/2011/02/insid...ve-module.html

-John

MrForbes 28-02-2011 10:58

Re: pic: Team 148 - 2011 - Raptor
 
Nice drive module!

for making that strange gear for the arm lifter....you could also get the arm gear from a door window regulator from a car, and trace it onto the aluminum


sdcantrell56 28-02-2011 12:47

Re: pic: Team 148 - 2011 - Raptor
 
Why did you decide to ditch the drop down perpendicular omni wheel this year? I would think strafing would be the only upside to this whole switching drivetrain

hurtzmyhead 28-02-2011 13:28

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by sdcantrell56 (Post 1032639)
Why did you decide to ditch the drop down perpendicular omni wheel this year? I would think strafing would be the only upside to this whole switching drivetrain

Im not sure that they did: Looks like they can go side to side

if im mistaken and it does not have a 5th omni to go side to side... here it shows the robot "auto magically" lining up to the pole.

tim-tim 28-02-2011 13:30

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by sdcantrell56 (Post 1032639)
Why did you decide to ditch the drop down perpendicular omni wheel this year? I would think strafing would be the only upside to this whole switching drivetrain

From the blog on the drive module, he states that there is a reduction through gears and another through chain. This essential provides a two speed transmission with two different driving characteristics. This will allow for a change of speed and torque. The omni-wheels still provide more degrees of freedom for the robot to move in, than IFI traction wheels.

There are plenty of advantages to this system. I really like this system and hope to develop something similar in the off-season.

-Tim

Chris is me 28-02-2011 13:57

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by tim-tim (Post 1032659)
From the blog on the drive module, he states that there is a reduction through gears and another through chain. This essential provides a two speed transmission with two different driving characteristics. This will allow for a change of speed and torque. The omni-wheels still provide more degrees of freedom for the robot to move in, than IFI traction wheels.

If there is no powered movement in the lateral direction, they don't. However, I'm tempted to believe that 148 did put in the "kicker drive". I just don't see why they would choose an articulating drive like this if they couldn't strafe controllably.

I really like how the traction wheels are geared differently than the omni wheels. Simpler than shifting indeed!

tim-tim 28-02-2011 14:01

Re: pic: Team 148 - 2011 - Raptor
 
@ Chris, you do bring bring up a valid point. However, the omni-wheels will allow for a more maneuverable robot. This is what I was trying to say. Thanks for catching that

Joe G. 28-02-2011 14:10

Re: pic: Team 148 - 2011 - Raptor
 
I can imagine that the all-omni wheel drivetrain would create a nice "drift" effect when turning around during high-speed motion, a maneuver that can be seen at about 1:44 in their video. I can imagine that this will come in handy, due to the "back and forth" nature of driving in this game, and that this may have actually been hampered by the kicker wheel.

CAD drawings that flash by all feature a kicker wheel, as well as many practice bot pictures. But all footage of the final robot seems to place the battery in the center of the robot, in place of the mass of sheet metal that (presumably) supported the sideways wheel.

Also, John mentions a major change to subsystem 1 (the drivetrain) here. Coincidence? Or iterative design?

JVN 28-02-2011 14:45

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Joe G. (Post 1032683)
I can imagine that the all-omni wheel drivetrain would create a nice "drift" effect when turning around during high-speed motion, a maneuver that can be seen at about 1:44 in their video. I can imagine that this will come in handy, due to the "back and forth" nature of driving in this game, and that this may have actually been hampered by the kicker wheel.

CAD drawings that flash by all feature a kicker wheel, as well as many practice bot pictures. But all footage of the final robot seems to place the battery in the center of the robot, in place of the mass of sheet metal that (presumably) supported the sideways wheel.

Also, John mentions a major change to subsystem 1 (the drivetrain) here. Coincidence? Or iterative design?

You got it.
The original drivetrain was a full Nonadrive system, but we ended up removing the sideways wheels around Day 31 (see the blog post linked above). After a week of practice we decided it wasn't necessary. In my mind, all our work and testing since that point has confirmed we made the right decision.

When we removed the middle wheel our original plan was to swap out the 4 primary omni wheels with 6" traction wheels, however... well... we were impressed with what our driver Connor can do with it.

We call this configuration "Butterfly Drive." Which is a joke in reference to how this robot can be pushed sideways while on all omni wheels (obviously when we drop the traction wheels she stops floating like a butterfly and stings like a... you know.)

I don't think all of it's virtues are readily apparent. I assure you there are more reasons to do an articulating drive than moving sideways. Though I realize most other teams may not value the same things we do, and as such may not make the same tradeoffs we did.

We love "traction mode" and it's virtues in autonomous and driver control. We love the simplicity and modularity of this module design. We love how the drivetrain performs on all omni-wheels (super efficient geartrain + 4 omni wheels = smooth like butter). We're very happy with what we ended up with...

-John

sanddrag 28-02-2011 15:13

Re: pic: Team 148 - 2011 - Raptor
 
I remember way back to 2003, team 980 had a similar drive system in which they raised or lowered two different sets of wheels to essentially have two different final drive speeds/ratios.

Manoel 28-02-2011 15:16

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by sanddrag (Post 1032709)
I remember way back to 2003, team 980 had a similar drive system in which they raised or lowered two different sets of wheels to essentially have two different final drive speeds/ratios.

Team 810 did the same thing in 2002, from what I remember.

sdcantrell56 28-02-2011 17:26

Re: pic: Team 148 - 2011 - Raptor
 
While I think its cool shifting wheels instead of shifting gears, I don't really see how it is simpler at all. A transmission is quite compact and requires a small amount of force to shift versus needing enough force to lift the robot to drop down the traction wheels. The only potential benefit I see of this system without the perpendicular omni wheel is the ability to change the center of rotation although the benefit of that wouldn't necessarily be worth the added weight of the system.

JVN given that you ended up taking out the 5th omni wheel would you stick with this drive if you could do it over or go with a more conventional 6 or 8wd with shifting transmission?

AdamHeard 28-02-2011 17:32

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by sdcantrell56 (Post 1032795)
While I think its cool shifting wheels instead of shifting gears, I don't really see how it is simpler at all. A transmission is quite compact and requires a small amount of force to shift versus needing enough force to lift the robot to drop down the traction wheels. The only potential benefit I see of this system without the perpendicular omni wheel is the ability to change the center of rotation although the benefit of that wouldn't necessarily be worth the added weight of the system.

JVN given that you ended up taking out the 5th omni wheel would you stick with this drive if you could do it over or go with a more conventional 6 or 8wd with shifting transmission?

From a fabrication standpoint for a team with limited resources, it is far easier. Having worked through the "fun" of getting the speeds right for multiple gearboxes, it is also nice in that it is easier to change the difference between high and low gear.

Utlizing COTS gearboxes and wheels, a team with a drill press (or even a hand drill), could make such a drivetrain.

Chris is me 28-02-2011 17:37

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by AdamHeard (Post 1032798)
Utlizing COTS gearboxes and wheels, a team with a drill press (or even a hand drill), could make such a drivetrain.

While it can be done with less resources, I'd be worried about these low resource teams trying this, mainly because wheel pod side loading is a pretty big concern with this style of drivetrain.

By the way, the above blog post refers to large performance gains with the removal of the 5th wheel. What are those gains?

Andrew Schreiber 28-02-2011 18:53

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Chris is me (Post 1032800)
While it can be done with less resources, I'd be worried about these low resource teams trying this, mainly because wheel pod side loading is a pretty big concern with this style of drivetrain.

By the way, the above blog post refers to large performance gains with the removal of the 5th wheel. What are those gains?

Depends on the way you place your wheels. Obviously if you use omni wheels as your dropped wheels you will slide rather than break the pods. If you use traction wheels the problem becomes more significant.

Chris is me 28-02-2011 18:57

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Andrew Schreiber (Post 1032831)
Depends on the way you place your wheels. Obviously if you use omni wheels as your dropped wheels you will slide rather than break the pods. If you use traction wheels the problem becomes more significant.

Yes, but the system is designed around giving the traction wheels a higher reduction, so they aren't the natural choice to be directly driven / the pivot point.

Unless, of course, you've put the CIM on the module... like 148 does...

JVN 28-02-2011 18:58

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Andrew Schreiber (Post 1032831)
Depends on the way you place your wheels. Obviously if you use omni wheels as your dropped wheels you will slide rather than break the pods. If you use traction wheels the problem becomes more significant.

This was something we learned last year, which is why the Generation 3 & 4 drivetrains have stationary traction wheels and actuated omni wheels. When we're in traction mode if we take a hit, all the load gets transferred straight into the chassis.

This layout comes with its own set of challenges and constraints, but we like it a lot more.

-John

Dad1279 28-02-2011 20:32

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Chris is me (Post 1032800)
While it can be done with less resources, I'd be worried about these low resource teams trying this, mainly because wheel pod side loading is a pretty big concern with this style of drivetrain.

By the way, the above blog post refers to large performance gains with the removal of the 5th wheel. What are those gains?

Not to hi-jack, but that's how we did it, Drill press and bandsaw. Only machined parts are the two plates. Traction wheels direct drive, larger mecanums raised and lowered. 1-CIM 1-775 per module.


Side loading is not a problem, as the traction wheels are mounted conventionally with a bearing on both sides of shaft, and the mecanums are braced with sideplates/slides. Obviously not all is shown in this rendering.

JVN 01-03-2011 09:34

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JVN (Post 1030614)
After receiving a number of requests in response to this post, I decided to highlight some of the subtle parts of this year's design on my blog as part of an "Inside Raptor" series.

Another in this series:
http://blog.iamjvn.com/2011/02/insid...retainers.html

Want to retain a flanged bearing? Drill some holes and rivet a washer over the flange.

-John

Alex Cormier 01-03-2011 10:29

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JVN (Post 1033053)
Another in this series:
http://blog.iamjvn.com/2011/02/insid...retainers.html

Want to retain a flanged bearing? Drill some holes and rivet a washer over the flange.

-John

Did you also replace the bolts in the AM omnis with rivets?

Greg Needel 01-03-2011 10:47

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Alex Cormier (Post 1033071)
Did you also replace the bolts in the AM omnis with rivets?

Yes we did and they haven't failed us yet. Not sure how much weight we saved by doing this but anything we can do to save a little bit is worth the effort. Additionally by doing this it was and opportunity to check each roller to make sure it rolled freely.

Madison 01-03-2011 12:35

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Manoel (Post 1032712)
Team 810 did the same thing in 2002, from what I remember.

810 used 9" Bead-lok wheels for its main drive and lowered two absurdly wide belts to the ground for pushing. I don't recall the overall ratios, but the difference between the wheels and belts was 3:1.

Captaindan 01-03-2011 23:30

Re: pic: Team 148 - 2011 - Raptor
 
haha fusion answered the call for awsome funchional leds check it out at the bayou regional ladies and gentlemen

lynca 02-03-2011 01:02

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Greg Needel (Post 1033079)
Yes we did and they haven't failed us yet. Not sure how much weight we saved by doing this but anything we can do to save a little bit is worth the effort. Additionally by doing this it was and opportunity to check each roller to make sure it rolled freely.

I've noticed that our omni rollers eventually stop spinning. We have tried loosening the screws but sometimes we have to change the rollers completely.

How often do you guys swap out rollers ?

Did you notice any difference between riveting omnis instead of screws ?

Akash Rastogi 02-03-2011 11:48

Re: pic: Team 148 - 2011 - Raptor
 
On the topic of plate gears, I remembered that 1771 had plate gears integrated into their turreted shooter's hood. The entire thing was also turreted on a huge laser cut sprocket. Guess they should've published some documentation on their robots! What a dominant machine they had that year.

I'm hoping 1477 and 2415 also have some cool integrated components in the coming seasons.

For anyone interested, it was a simple but pretty cool application.

Andrew Schreiber 02-03-2011 11:52

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Akash Rastogi (Post 1033624)
On the topic of plate gears, I remembered that 1771 had plate gears integrated into their turreted shooter's hood. The entire thing was also turreted on a huge laser cut sprocket. Guess they should've published some documentation on their robots! What a dominant machine they had that year.

I'm hoping 1477 and 2415 also have some cool integrated components in the coming seasons.

For anyone who is feeling left out on the laser-cutty-goodness you can achieve a similar effect by taking a length of timing belt and wrapping your circular surface in it with the teeth facing out. It isn't as effective as having the teeth laser cut but for low torque applications it does work. 2337 use this approach somewhere on their 2009 robot (I'll snap a pic next time I am down there).

jwfoss 02-03-2011 12:31

Re: pic: Team 148 - 2011 - Raptor
 
The adjustable length four bar link is a really slick trick. I've had that sketched out in my engineering notebook since the first time I ever saw that done back in 2008 at FLR. They had an adjustable lower link to stay within the sizing rules and to tilt the gripper up, whereas you adjust your upperlink to actuate your wrist. Also I believe theirs may have been passive (gas shock) where your is pnuematically adjusted.

FRC67 - HOT from 2008
http://www.chiefdelphi.com/media/photos/30680

pwnageNick 02-03-2011 12:52

Re: pic: Team 148 - 2011 - Raptor
 
This robot is awesome. My first year of FRC was last year, and I remember being very frightened after seeing your promo video last year. I can't wait to see how you guys do at Alamo this weekend. Good luck this season 148, 2949 can't wait to see you guys perform at Worlds!

Redo91 02-03-2011 21:00

Re: pic: Team 148 - 2011 - Raptor
 
You guys always impress.

Are you not worried with getting pushed too easily from the side when your traction wheels are up?
How well does the robot turn when the traction wheels are down?

I wish I could see your robot in person.

Adam Freeman 02-03-2011 21:55

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by jwfoss (Post 1033641)
The adjustable length four bar link is a really slick trick. I've had that sketched out in my engineering notebook since the first time I ever saw that done back in 2008 at FLR. They had an adjustable lower link to stay within the sizing rules and to tilt the gripper up, whereas you adjust your upperlink to actuate your wrist. Also I believe theirs may have been passive (gas shock) where your is pnuematically adjusted.

FRC67 - HOT from 2008
http://www.chiefdelphi.com/media/photos/30680

Unfortunately our 2008 adjustable lower link design never made it passed our practice field. The mechanical implementation on that design (PVC and gas shocks) had a serious transition phase that caused our programmers fits. We ended up re-designing the lower arm and replacing it with a solid link as soon as it came out of the crate Thursday morning @ FLR.

Raptor's adjustable arm is much more elegant and functional than that HOT '08 adjustable arm ever dreamed of being.

JVN 02-03-2011 22:15

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JVN (Post 1030614)
After receiving a number of requests in response to this post, I decided to highlight some of the subtle parts of this year's design on my blog as part of an "Inside Raptor" series.

Another post in this series, my last before we take her out of the bag tomorrow morning at the Alamo regional:
http://blog.iamjvn.com/2011/03/insid...ntiometer.html

Our programmers accuse me of having a mental block which keeps me from designing sensors into the robot. To them I say: "BAGH!"

Good Luck to everyone who competes in week 1!
Raptor has one more big surprise up her sleeve which is ready to go. See you on the field ;)

-John

JesseK 03-03-2011 12:22

Re: pic: Team 148 - 2011 - Raptor
 
Hmm. More compactness (potentially):

1. Fix 2 long VEX metal pieces to the dead axle of the arm such that one of the square holes is concentric with the axle. The hole will have to be enlarged of course. The two pieces of metal should be far enough apart that the slop is minimized, regardless of whether the potentiometer gear is cantilevered or dual-supported.
2. Attach the VEX gear to the arm, as shown.
3. Attach the potentiometer and the potentiometer gear to the VEX metal using appropriate spacing for the chosen gears. The spacing is built-in since it's VEX.
4. Profit.

We've always had issues with potentiometers since we can't seem to keep them from slipping in the shafts we directly mount them to (thus needing to recalibrate them). Or the rubber band / polycord belts we make slip. It results in a bad calibration. Maybe we can try VEX this off season. Right now we use limit switches with encoders -- not too bad coding-wise, but man that's a lot of little wires to run.

Travis Hoffman 03-03-2011 12:32

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by JesseK (Post 1034082)

We've always had issues with potentiometers since we can't seem to keep them from slipping in the shafts we directly mount them to (thus needing to recalibrate them).

Quite evil, that.

Cross-drill a hole through the pot shaft and the mechanism shaft, and secure with a cotter pin or other suitable clip, bolt, whatever.

ChuckDickerson 04-03-2011 17:24

Re: pic: Team 148 - 2011 - Raptor
 
148 just scored 2 uber tubes BY THEMSELVES in autonomous during match number 55 at Alamo! Now folks, THAT defines just how uber cool 148 are!

waialua359 04-03-2011 18:11

Re: pic: Team 148 - 2011 - Raptor
 
Nice job!
That's two teams now that can score 2 in auto.
The other being that one Michigan team that posted a video of it.:rolleyes:

Tom Bottiglieri 04-03-2011 18:23

Re: pic: Team 148 - 2011 - Raptor
 
Hey John that's a pretty cool piece of SOFTWARE you've got there. ;)

JVN 07-03-2011 11:31

Re: pic: Team 148 - 2011 - Raptor
 
Some video of Raptor in the elimination rounds of the 2011 Alamo Regional:
http://blog.iamjvn.com/2011/03/san-a...011-video.html

Check out Final 1 for a glimpse of the week 1 national high score, and our 2 tube autonomous mode.

tim-tim 22-02-2012 22:02

Re: pic: Team 148 - 2011 - Raptor
 
The 2012 release should be in the near future.

Correction, the much anticipated 2012 release should be in the near future, and I can't wait.

Andrew Lawrence 22-02-2012 22:05

Re: pic: Team 148 - 2011 - Raptor
 
Aww. Got me excited over last year's robot. :(

stundt1 22-02-2012 22:06

Re: pic: Team 148 - 2011 - Raptor
 
http://www.youtube.com/watch?v=g3jeR...eature=channel

There human player has skill.

its da PAT!!! 22-02-2012 22:09

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by SuperNerd256 (Post 1133061)
Aww. Got me excited over last year's robot. :(

I know right? I saw that and got so excited. lol

V_Chip 22-02-2012 22:10

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by stundt1 (Post 1133063)

Isn't he from 118 Robonauts?

s_forbes 22-02-2012 22:11

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by stundt1 (Post 1133063)

I see a robot in the background that may be of interest.

Peyton Yeung 22-02-2012 22:13

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by s_forbes (Post 1133070)
I see a robot in the background that may be of interest.

Looks like a wide base

V_Chip 22-02-2012 22:13

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by s_forbes (Post 1133070)
I see a robot in the background that may be of interest.

I see a wide config bot :)

CalTran 22-02-2012 22:16

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by SuperNerd256 (Post 1133061)
Aww. Got me excited over last year's robot. :(

I'm thinking the same thing.
Replay of the last few moments:
:eek: 148 released their robot already?? :confused: *reads thread* :mad: I got played.

Walter Deitzler 22-02-2012 22:16

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by Tubatroopa (Post 1133072)
Looks like a wide base

It is definetly a wide base.
I almost mistook it for the Raptor when I first saw it, becuase of the triangular frame. I wonder how it looks...:confused:

V_Chip 22-02-2012 22:21

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by LedLover96 (Post 1133077)
It is definetly a wide base.
I almost mistook it for the Raptor when I first saw it, becuase of the triangular frame. I wonder how it looks...:confused:

http://s1199.photobucket.com/albums/aa476/V_Chip/

tim-tim 22-02-2012 22:22

Re: pic: Team 148 - 2011 - Raptor
 
Sorry for the false hope guys. It is not unusual for 148 to release their robot soon after the ship/bag&tag deadline.

I will agree that it does appear to be a wide based robot. However, I would not put it past JVN and Greg to have placed a 'fake' robot in the back corner to create discussion...

I am just waiting on how simple their design will be (as always, simple, clean, and effective).

Walter Deitzler 22-02-2012 22:25

Re: pic: Team 148 - 2011 - Raptor
 
It looks as if they have a tall bridge lowering arm or ball manipulator running up the front, then a shooter tower behind it. The image is too fuzzy to make out anything from there.

ChristopherSD 22-02-2012 22:51

Re: pic: Team 148 - 2011 - Raptor
 
Would it upset you all if I mentioned that this is their 2011 robot?

BrendanB 22-02-2012 22:57

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by ChristopherSD (Post 1133102)
Would it upset you all if I mentioned that this is their 2011 robot?

The picture in the video is not their 2011 based on the bumper configuration but i would laugh if they put a hole in them as a joke for the video!

akoscielski3 22-02-2012 22:57

Re: pic: Team 148 - 2011 - Raptor
 
Quote:

Originally Posted by ChristopherSD (Post 1133102)
Would it upset you all if I mentioned that this is their 2011 robot?

No cause you would be wrong. Their bumpers had to be all the way around last year and had numbers in the middle of bumpers. This clearly isnt.


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