Wheel shooter gearing

[sdcantrell56]

Originally Posted by R.C.

Clark, I would highly suggest gearing down to anywhere between 5,000 to 7,000 rpms. Free speed is way to darn fast.

-RC

To echo what RC is saying not only is it too fast but it is DANGEROUS!

[jwfoss]

With 8" wheels you definitely want to gear the motors down. How much to gear down will depend on your configuration and desired range. In our experience single axle/hood shooters need to be geared 1/2 as much as a dual axle shooter to achieve the same distance. In other words, a single axle system has to spin twice as fast to get the same exit velocity.

For reference our design uses two 6" wheels on a single shaft with a hood with a 4:1 reduction using 2 FisherPrice (0673). We can shoot from the key and forward without a problem.

[Jon Stratis]

Here's our setup:

BaneBot 4 7/8" wheels on top and bottom, each independently powered by an RS-550 with a 7:1 gear reduction.

We measured the current into the motors when it was running at "full speed" to be about 7A each. Plug that into Ether's Motor Calculator, and we see that the speed of the motors is 18007 RPM. That gives us a speed of 2572 RPM for our shooter wheels, which is quite sufficient (we can hit the center of the top backboard from midfield, when running at "full speed").

Now, given that we're using smaller wheels than you, you should take that difference into account - you need about 5/8 the speed we have to get the ball to go the same distance - or about an 11:1 gear reduction.