Team 4276 Final Drive Prototype Testing

[seg9585]

Final drive system testing on our practice frame, going over most of the obstacles (port door/drawbridge not in scope of this test, chival de frise mods compatibility is in work).
This was mostly a "stress test" of our pneumatic wheel drive base and evaluating how we plan to use our collector arm to assist with the obstacles. Welding our final chassis tomorrow and working on integration of our shooter and climber prototypes.

https://www.youtube.com/watch?v=gdcFMtgxuIM

[orangemoore]

The Drive train looks awesome.


On side note you Rock Wall looks like it might not be built to spec.
http://www.firstinspires.org/robotic...stake-and-Q612

[seg9585]

We are aware of the changes to the rock wall dimensions but have not made any modifications to our field construction yet to accommodate. Based on our chassis height and wheel spacing we don't believe the larger width or height will be an issue (the increased width will actually help a bit). Thanks for pointing this out as a reminder though!

[T3_1565]

Looks good! I like how your intake was used to help you over the ramparts.

I also love seeing it drive slowly over, Gives a much better sense of what is happening.

Quick question: What is your wheel psi? Have you played around with that number at all yet?

We are hoping to have something driving tomorrow so its something I'm currently thinking about! lol

[seg9585]

Originally Posted by T3_1565

Looks good! I like how your intake was used to help you over the ramparts.

I also love seeing it drive slowly over, Gives a much better sense of what is happening.

Quick question: What is your wheel psi? Have you played around with that number at all yet?

We are hoping to have something driving tomorrow so its something I'm currently thinking about! lol

We use the arm as leverage for the ramparts and some of the other obstacles to position our CG. The arm is actually strong enough to pick up the middle wheels if we got stuck anywhere (another part of this test). We drove over the obstacles at both slow speeds and fast speeds to look at the dynamics of the wheels and impact angles after crossing (especially landing after the rock wall).

Great question about the pneumatic wheel pressure -- we first tested with pressure maximized at the tire's pressure rating (32psi?) and the robot was very bouncy (you can see that here). For the tests in the original thread, we lowered the pressure to about 10psi and below which gives us great dampening and more surface area to get traction. We are still trying to decide on our final pressure but we know it will be low.

[T3_1565]

I can assume that's at full weight as well? It's nice to see that you tested it so many different ways!

Exactly how to learn whats best for you bot!

Thanks for the response!

[SenorZ]

Originally Posted by T3_1565

I can assume that's at full weight as well? It's nice to see that you tested it so many different ways!

Exactly how to learn whats best for you bot!

Thanks for the response!

Robot weight as tested was about 85lb. Thats about 15 under total expected. We had a shooter mechanism "on" the robot but not powered, and our scaling mechanism was on a table someplace.

BUT, that 85lb robot can push with 233lb of force

[T3_1565]

Originally Posted by SenorZ

Robot weight as tested was about 85lb. Thats about 15 under total expected. We had a shooter mechanism "on" the robot but not powered, and our scaling mechanism was on a table someplace.

BUT, that 85lb robot can push with 233lb of force

I am looking more at how the weight affects its bounce with regards to wheel pressure.

Is that 85lbs including battery?

[SenorZ]

No battery.
Also, in the "bouncy" video you can see we took the arm off due to some spontaneous dismantling. That made the robot lighter still.

The final prototype video at the top has some pretty low PSI wheels. You can see that the center wheel looks almost flat on the robot's left side.

We're eager to test this on something closer to the actual field. Linoleum and plywood doesn't substitute for carpet, HDPE, and aluminum.