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-   -   What wheel to use for the flywheel (http://www.chiefdelphi.com/forums/showthread.php?t=154981)

lamk 08-02-2017 23:04

What wheel to use for the flywheel
 
Out team is trying to build a single flywheel shooter. Currently we are using a 4" colson performa wheel that is 2 inch wide. Despite Pid control and trying various compression, our shots are all over the place. Any suggestion on the wheel choice and the amount of compression that may improve our consistency will be greatly appreciated.
Thanks

EricH 08-02-2017 23:08

Re: What wheel to use for the flywheel
 
Have you tried putting a second, identical wheel on the same axle? Or, how about splitting the 2" wheel into two 1" wheels? The resulting "groove" should allow a straighter track through the shooter. It's not an uncommon setup for FRC shooters.

lamk 08-02-2017 23:14

Re: What wheel to use for the flywheel
 
Thanks for the suggestion. We will try that tomorrow.

Fusion_Clint 08-02-2017 23:25

Re: What wheel to use for the flywheel
 
Colson's are too hard this year. Try a soft rubber wheel for your flywheel.

lamk 08-02-2017 23:51

Re: What wheel to use for the flywheel
 
We are starting to think along those line too. I think my team build a reasonably good cage and hood for the flywheel and we have done everything we knew to tweak it. We will look at a softer wheel.

s_forbes 08-02-2017 23:55

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Fusion_Clint (Post 1642333)
Colson's are too hard this year. Try a soft rubber wheel for your flywheel.

I really want to see slow motion footage of a ball leaving a shooter that has a soft rubber wheel. I'd guess that at the speed the shooter wheel spins at, there is enough centripetal force pulling outward on the wheel that it acts like a hard rubber wheel rather than a soft one.

Ekcrbe 09-02-2017 00:03

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by lamk (Post 1642344)
We are starting to think along those line too. I think my team build a reasonably good cage and hood for the flywheel and we have done everything we knew to tweak it. We will look at a softer wheel.

Try rolling the balls through the shooter by hand, putting them in the bottom and spinning the wheel with the robot powered off. This is a pretty subjective and variable thing, but you want the ball to resist going through somewhat without really getting stuck or sliding by freely. (There also should not be one spot early in the ball's path that is much tighter than elsewhere.) This is a rough indication of whether you have a dearth or excess of compression. If you have too little compression, some balls will probably not catch well and receive less energy than others. Conversely, if you have too much compression, the aggressive deformation the balls are undergoing can make their trajectories hard to predict upon exit.

The equalizing factor, as Clint said, may well be trying a softer wheel that allows more compression to come from the forgiving wheel rather than the balls.

Fusion_Clint 09-02-2017 00:22

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by s_forbes (Post 1642345)
I really want to see slow motion footage of a ball leaving a shooter that has a soft rubber wheel. I'd guess (https://www.youtube.com/watch?v=Fps6S03aWyE) that at the speed the shooter wheel spins at, there is enough centripetal force pulling outward on the wheel that it acts like a hard rubber wheel rather than a soft one.

The flywheel has to grab the fuel consistently and bring it into the shooting mechanism, the colsons slip a lot before actually taking the fuel into the shooting mechanism, resulting in inconsistent velocity and distance.

YMMV, just some results from our tests.

lamk 09-02-2017 00:39

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Fusion_Clint (Post 1642356)
The flywheel has to grab the fuel consistently and bring it into the shooting mechanism, the colsons slip a lot before actually taking the fuel into the shooting mechanism, resulting in inconsistent velocity and distance.

YMMV, just some results from our tests.

Which wheel will you recommend?

Munchskull 09-02-2017 01:28

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by lamk (Post 1642358)
Which wheel will you recommend?

The new andymark wheels.

theawesome1730 09-02-2017 01:46

Re: What wheel to use for the flywheel
 
Space and weight allowing, more massive flywheels can be more easily regulated using PID. Through conservation of momentum, a large mass flywheel will transfer less of its momentum to the fuel than a less massive flywheel for each shot. It will take longer to reach optimal shooting angular velocity, but will maintain that angular velocity much more easily. If it's possible you may look into that in addition to different wheel surfaces

Cothron Theiss 09-02-2017 01:51

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Munchskull (Post 1642363)
The new andymark wheels.

Just for clarity, I assume Anthony is referring to these, as well as the other compliant wheels AndyMark has released this past season.

To the OP, a picture of your current setup would help us all dig into the minutia of your design and offer advice, if you so choose.

Tom Line 09-02-2017 02:04

Re: What wheel to use for the flywheel
 
https://www.chiefdelphi.com/forums/s...4&postcount=17

Not much has changed, really.

Richard Wallace 09-02-2017 10:22

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Tom Line (Post 1642372)

This is why I love the laws of physics. Everyone has to obey them all the time. They don't care who has been elected police commissioner, president, or dogcatcher.

Jon Stratis 09-02-2017 11:10

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by s_forbes (Post 1642345)
I really want to see slow motion footage of a ball leaving a shooter that has a soft rubber wheel. I'd guess that at the speed the shooter wheel spins at, there is enough centripetal force pulling outward on the wheel that it acts like a hard rubber wheel rather than a soft one.

Our initial prototype used the 4" traction wheels that have come in the KoP in the past (very hard). It worked well enough, but even with only a moderate amount of compression you could hear/see the CIM motor powering it practically stall when a ball went through. Switch that out to the AndyMark compliant wheels, and now with the same setup (same compression, same motor, same gear ratio, literally the only difference is changing one 4" wheel for another) we can feed in a whole row of balls without any noticeable slowdown with the motor. The compliant wheels really do make a difference.

SenorZ 09-02-2017 12:01

Re: What wheel to use for the flywheel
 
Two banebots blue wheels, 3-7/8", seem to have good inertia. And they grip well. Only issue is the already talked about "film" build up on the wheels after shooting a lot of fuel.

Varying the compression even an eighth of an inch had a big impact, so make sure you're not using a narrow flywheel. The holes in the fuel will ruin all your planning.

Fusion_Clint 09-02-2017 12:32

Re: What wheel to use for the flywheel
 
This is what we are using. https://www.mcmaster.com/#2497k16/=16a565k

ShIfTiNgBoT 09-02-2017 12:44

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by SenorZ (Post 1642489)
Varying the compression even an eighth of an inch had a big impact, so make sure you're not using a narrow flywheel. The holes in the fuel will ruin all your planning.

Or conversely, not enough compression mixed with small wheels will be ruined by the holes.

lamk 09-02-2017 15:12

Re: What wheel to use for the flywheel
 
Didn't realize there are two type of 4"wheel with 50a durometer
I order the stealth wheel and then see people talking about the compliant wheel.
Does anybody know how different they are
Should I buy the compliant wheel instead

Cothron Theiss 09-02-2017 15:21

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by lamk (Post 1642610)
Didn't realize there are two type of 4"wheel with 50a durometer
I order the stealth wheel and then see people talking about the compliant wheel.
Does anybody know how different they are
Should I buy the compliant wheel instead

There is a world of difference. The stealth wheels, while great for quick intakes and grippiness, have a lower moment of inertia and are not at all compliant. I would not suggest using stealth wheels as your shooter wheels.

Type 09-02-2017 15:24

Re: What wheel to use for the flywheel
 
My team actually have been using 4" x 2" Colsons, we filed the wheel down so that it wasn't crowned anymore and we have had amazing consistency so far.

Sperkowsky 09-02-2017 16:20

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Cothron Theiss (Post 1642617)
There is a world of difference. The stealth wheels, while great for quick intakes and grippiness, have a lower moment of inertia and are not at all compliant. I would not suggest using stealth wheels as your shooter wheels.

Stealth wheels make great shooter wheels. Better than compliant wheels in our testing. We were easily able to shoot vertically upwards of 14ft vertically

waialua359 09-02-2017 16:34

Re: What wheel to use for the flywheel
 
Our team has had a 90% built robot for the past 1 1/2 weeks.
We tried many things from weight of flywheel, adjustments to speed, varying the metering feeder wheels, indexing of balls, and shooter width.
We also incorporated the use of a PID using the VEXPro Versa gearbox with an integrated encoder using a 2-775 Pro setup.

The biggest factor we are finding are orientation of the balls as it enters our metering wheel and then shooter. Orient them all the same way and we will hit 29 of 30 shots. Orient them another way and we will miss practically all of them.

So how do we account for it?

Well, thats today and tomorrow's adjustment.:rolleyes:
If that doesnt work, we will live with what we have.

If we slow things down a bit, we can achieve close to 80% accuracy.
If we shoot as fast as possible, we can shoot 30 to 35 balls in less than 5 seconds, making 50-60% of the shots.

Hopefully, with our adjustments today, we can shoot fast but achieve a much higher success rate.
If we can do that, we plan to share it with all of our Hawaiian friends here. :)

Jon Stratis 09-02-2017 16:38

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Sperkowsky (Post 1642671)
Stealth wheels make great shooter wheels. Better than compliant wheels in our testing. We were easily able to shoot vertically upwards of 14ft vertically

We hit the 19ft ceiling in our shop shooting with the compliant wheels when we first ran them (CIM motor, 1:1 chain driven) at full power. We dialed it way back for further testing :)

cadandcookies 09-02-2017 17:14

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Sperkowsky (Post 1642671)
Stealth wheels make great shooter wheels. Better than compliant wheels in our testing. We were easily able to shoot vertically upwards of 14ft vertically

Quote:

Originally Posted by Jon Stratis (Post 1642682)
We hit the 19ft ceiling in our shop shooting with the compliant wheels when we first ran them (CIM motor, 1:1 chain driven) at full power. We dialed it way back for further testing :)

It's almost like there might be more factors than wheel type when it comes to shooters.

Seriously though, I'm pretty confident we'll see effective shooters using a variety of wheel types. I am not confident that there is an "in general" superior shooter wheel when it comes to COTS parts. So many factors such as compression, feeding, and style of shooter will affect what characteristics you're looking for in your shooter wheel.

gpetilli 09-02-2017 17:31

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by waialua359 (Post 1642680)
Our team has had a 90% built robot for the past 1 1/2 weeks.
We tried many things from weight of flywheel, adjustments to speed, varying the metering feeder wheels, indexing of balls, and shooter width.
We also incorporated the use of a PID using the VEXPro Versa gearbox with an integrated encoder using a 2-775 Pro setup.

The biggest factor we are finding are orientation of the balls as it enters our metering wheel and then shooter. Orient them all the same way and we will hit 29 of 30 shots. Orient them another way and we will miss practically all of them.

So how do we account for it?

Well, thats today and tomorrow's adjustment.:rolleyes:
If that doesnt work, we will live with what we have.

If we slow things down a bit, we can achieve close to 80% accuracy.
If we shoot as fast as possible, we can shoot 30 to 35 balls in less than 5 seconds, making 50-60% of the shots.

Hopefully, with our adjustments today, we can shoot fast but achieve a much higher success rate.
If we can do that, we plan to share it with all of our Hawaiian friends here. :)

I totally agree that you need to control how the ball enters the flywheel.

That said, I have a few specific questions:
1) what wheel are you using?
2) what compression are you targeting?
3) what exactly do you mean by a "metering" wheel? (I have a guess)

waialua359 09-02-2017 17:35

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by gpetilli (Post 1642707)
I totally agree that you need to control how the ball enters the flywheel.

That said, I have a few specific questions:
1) what wheel are you using? Banebot Green wheels 2 7/8" diameter
2) what compression are you targeting? I failed to mention earlier that we have tried various compressions. We mounted our shooter wheel to the frame with aluminum blocks that allows us to easily swap out different widths adjusting the compression. We vary them by 1/8".
3) what exactly do you mean by a "metering" wheel? (I have a guess)

Similar to our flywheel that feeds balls into the shooter from the hopper.

Ty Tremblay 09-02-2017 17:54

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by waialua359 (Post 1642680)

The biggest factor we are finding are orientation of the balls as it enters our metering wheel and then shooter. Orient them all the same way and we will hit 29 of 30 shots. Orient them another way and we will miss practically all of them.

What do you mean by the orientation of the balls? Aren't they pretty close to spherically symmetric?

Cothron Theiss 09-02-2017 17:58

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Sperkowsky (Post 1642671)
Stealth wheels make great shooter wheels. Better than compliant wheels in our testing. We were easily able to shoot vertically upwards of 14ft vertically

I agree. Just about any wheel can be used with success if the rest of the system is good. But if the OP is having issues with Colsons, I doubt stealth wheels will be better. Grnated, switching to compliant wheels probably won't make all their shooter problems go away either, but compliant wheels may be a better wheel for the rest of their setup than Colsons or stealth wheels.

waialua359 09-02-2017 18:21

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Ty Tremblay (Post 1642715)
What do you mean by the orientation of the balls? Aren't they pretty close to spherically symmetric?

For a specific set of adjustments we tried to make to optimize success rate, we find that when the seams of the ball are perpendicular to the shooter wheel, it is much more consistent than lined up horizontally.
Our shot up close can change by as much as 2ft as well as varying velocity and arc path.

lamk 10-02-2017 01:38

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Type (Post 1642618)
My team actually have been using 4" x 2" Colsons, we filed the wheel down so that it wasn't crowned anymore and we have had amazing consistency so far.

We actually did that already and it didn't help. What is the compression your team use and how much of an arc that the ball contact the hood. Thanks.

Valkonn 10-02-2017 02:22

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Cothron Theiss (Post 1642617)
There is a world of difference. The stealth wheels, while great for quick intakes and grippiness, have a lower moment of inertia and are not at all compliant. I would not suggest using stealth wheels as your shooter wheels.

The inertia problem can be fixed with a flywheel. The design of a stealth wheel (partially hollow) also makes it easy to mount additional mass right into the shooter itself. And if your problem has anything to do with compliance, I'd say it's likely you have a problem with too much compression...

We were hitting the roof of our building quite easily at full power with blue 4 inch diameter stealth wheels. I don't know the exact number but its 25 to 30 feet of height. Couple that with extreme accuracy (hitting the center of a roof tile many times consecutively) and I'd say stealth wheels are a-ok for shooting.

CalTran 10-02-2017 02:29

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by waialua359 (Post 1642721)
For a specific set of adjustments we tried to make to optimize success rate, we find that when the seams of the ball are perpendicular to the shooter wheel, it is much more consistent than lined up horizontally.

Now I'm curious how you designed a hopper and indexer that could possibly line it up in a reasonable manner.

waialua359 10-02-2017 05:00

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by CalTran (Post 1642848)
Now I'm curious how you designed a hopper and indexer that could possibly line it up in a reasonable manner.

That's easy. By hand😃

gpetilli 10-02-2017 08:25

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Valkonn (Post 1642847)
The inertia problem can be fixed with a flywheel. The design of a stealth wheel (partially hollow) also makes it easy to mount additional mass right into the shooter itself. And if your problem has anything to do with compliance, I'd say it's likely you have a problem with too much compression...

We were hitting the roof of our building quite easily at full power with blue 4 inch diameter stealth wheels. I don't know the exact number but its 25 to 30 feet of height. Couple that with extreme accuracy (hitting the center of a roof tile many times consecutively) and I'd say stealth wheels are a-ok for shooting.

so what compression are you running?

Chris is me 10-02-2017 08:47

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by Cothron Theiss (Post 1642716)
I agree. Just about any wheel can be used with success if the rest of the system is good. But if the OP is having issues with Colsons, I doubt stealth wheels will be better. Grnated, switching to compliant wheels probably won't make all their shooter problems go away either, but compliant wheels may be a better wheel for the rest of their setup than Colsons or stealth wheels.

Stealth wheels perform dramatically differently than Colson wheels in terms of acting as a shooter. Please don't speak from experience if you don't have said experience - at least qualify your statements with "I think" and / or explaining why you're making the assumption that you are.

All that said, I've had great experiences shooting with compliant wheels, I think they're great for this game piece.

Type 10-02-2017 09:12

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by lamk (Post 1642846)
We actually did that already and it didn't help. What is the compression your team use and how much of an arc that the ball contact the hood. Thanks.

Our compression we have been varying and due to welding right now, I've been separated from my team. I know that it is not a lot. The arc of the hood is very little.

Valkonn 10-02-2017 13:23

Re: What wheel to use for the flywheel
 
Quote:

Originally Posted by gpetilli (Post 1642872)
so what compression are you running?

About an eighth of an inch, maybe a few thousandths more.

xjschwen 10-02-2017 15:02

Re: What wheel to use for the flywheel
 
Our one wheel shooter prototype was an 8 inch wheel powered direct drive with a cim and we had plenty of distance and had some accuracy issues.

Our 4 wheel shooter prototype was 4 - 4 inch compliant wheels on 2 shafts powered by 2 mini cims. First prototype testing we hit the same 2" pipe along our ceiling for 10 shots in a row with plenty of power to spare. The pipe is about 12 feet straight up.

We did no further tests.


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