Ideal compression for flywheel?

[Brandon Holley]

Originally Posted by Kenyow

I will be doing some tests on the ball today to find out how much force it takes to compress the ball X amount, and how that relates to the torque required on the motors running the shooter. I will try to post the results on this thread later. Maybe as a formula. Stay tuned!

We've done similar testing and come up with interesting results. Good luck!

-Brando

[cire]

I did some testing yesterday. it appeared the ball had about 7 lbs/inch of compression, this was pretty linear up to 3 inches where I stopped measuring. This was between two flat surfaces though, so i'd expect a different (lower) value if you had a single wheel or were riding on rails with the ball.


I wonder how this compares to other teams measurements?

[Kenyow]

As promised, here are the results of the tests on ball compression. And how to use them. I took a pressure plate and placed the ball on top, and rigged a system where i could lower a surface in half inch increments and measure the force on the ball. Here is what i got. I would encourage other teams to try it out for themselves.

0.0in 0.0 N
0.5in 22.3 N
1.0in 45.8 N
1.5in 66.5 N
2.0in 90.4 N
2.5in 112.6 N
3.0in 127.6 N

If you want to know the torque needed on the motor, use this formula:

Torque = Force of compression X Radius of the shooter wheel X The compressed coefficient of friction between the ball and the shooter.

Hope this helps

[gpetilli]

Originally Posted by Brandon Holley

We've done similar testing and come up with interesting results. Good luck!

-Brando

Please share !!!! Would be good to see if two teams can get similar results.

[waialua359]

we have a 1.5"-2" compression for our shooter prototype and we found no real difference between that range.
1" didnt have as much distance/power as it left our shooter through repeated tests.

Different designs will have different optimal compression requirements.
Best to test it out and see for yourself what will work best.

[JamesCH95]

Originally Posted by waialua359

we have a 1.5"-2" compression for our shooter prototype and we found no real difference between that range.
1" didnt have as much distance/power as it left our shooter through repeated tests.

Different designs will have different optimal compression requirements.
Best to test it out and see for yourself what will work best.

We determined experimentally that 1.5" of compression with nominally 1.5" diameter rollers worked pretty well. It is encouraging to see other teams getting the same numbers!