pic: 888 Ball Shooter Prototype

Prototype for team 888 who I am working with as a mentor/college student. They thought it would be cool if I posted a picture.

Looks cool.
How much range/accuracy do you get out of it?

have you tested this yet? and does the current configuration put spin on the ball that either helps or hurts your shot?? cool setup btw…

Have not seen it work yet have been busy and out of the shop. But it is working and according to everyone it is pretty fast. They will update tommorow.
-Jeffrey Dewberry

First off, thanks.

What you can’t see is the mini-bike motor that drives it on the other side.

In its current configuration, it shoots about 30 feet, when elevated to a 30 degree angle.
According to a radar gun, it travels at 24-26 mph, just a bit more than 12 m/s.
Accuracy is decent, the person catching it at 30’ usually doesnt have to move to catch it. This should increase with an automatic feed.

I’m not sure if it puts a spin on the ball, its been too much fun just seeing it work, however, im sure i can test it out more tomorrow :slight_smile:

Looks cool. Are you using a belt to drive the shaft, or chains, or ??? Thanks!

We tied the shaft directly to the motor.

Its a piece of 5/8" shaft with a 5/16" hole in one end and two set screws pressing on the flattened spot of the CIM’s shaft.

Always remember, the “it’s just a prototype” attitude should never apply to electrical stuff. Sticking the wire leads off the CIM directly into the Anderson terminal of a battery to test your ideas is a baaaaaddddd idea. :ahh:

At the very least, put a fuse block in line - or - more preferable, put in a Victor. If you plug the Victor into the motor port of a Vex Controller, you can control it very easily for prototyping and without any need for programming. In the picture below, our team was able to successfully control the CIM motor using the Vex controller.

Don’t worry sir. We have been doing this for years with no problems and there our safe guards in place. We have not fryed a motor yet.

Nicely done. I really like both signs in the back to.

Yeah the no dumping sign is in our electronics work room. We put that there because people would always dump stuff in there. LoL

First off, thats not “our” electronics room. That is my personal office that I have been renting out to Team 888. (I’m still looking for a secretary. I’m looking for anyone who can write poems, fill waterbottles, make runs to RoFo, and keep my radios charged)

And we have a test board set up with a dpdt switch, breaker panel, battery connectors, and a battery mount that we use to test our prototypes. I would recommend that all teams with similar materials should build one of these boards as they make testing very easy. I can post the schematic if anyone wants it.

One of the things we found with this design is that it is important to have that metal sheet tangent to the wheel to provide the maximum friction.

I built the shooter and can say that it puts backspin on the ball which keeps it aloft longer.


doesn’t it take the motor a little longer to speed up a wheel that size to max speed? once up to speed does the wheel slow down at all after a ball has been dropped in? are you able to shoot more than one ball a second and have them go the same height distance and land in about the same area? just a few things we ran into in our prototyping stages with a similar set up.

Very cool prototype.

One Quick Question though,

How did you mount the Large CIM Motot?


We thought the wheel size would take awhile to speed up. (Based on preliminary tests with softball pitching machine), but the large CIM gets to speed fairly quickly.
We took off the belt tension thing and mounted the CIM flat against the plywood.

How did you mount it?
Did you drill and tap more holes?
Did you just use the mount that the tensioner lever was attached to?

We removed the pulley and used the existing stud, as well as drilling and tapping a hole in the corner that sticks out of the face.

Yes it does take the motor longer to accelerate than with lighter wheels but that wheel seems to shoot much better than the others we tested. Also, the wheel does slow when you launch a ball, but quickly regains the lost speed and you are able to shoot a ball accurately about every 1.5 s.