Gearing up two cims?
 

Are there any gear boxes that allow to gear UP two cims to something between 1:3 and 1:4? Preferably single stage. Thanks!

Re: Gearing up two cims?
 

Not a gear box, but it can easily be done with chain (though thats a VERY fast output.)

Re: Gearing up two cims?
 

MODULOX!

In all seriousness, Its what we used in Robot in 3 days. Worked fantastically.

- Andrew

Re: Gearing up two cims?
 

I'd be curious to know what you want to do with this, if you don't mind sharing.

Re: Gearing up two cims?
 

Hey Andrew,

Since you're reading this thread, maybe you could give a definitive answer to a question that's been bouncing around:

What CIM operating speed did you finally settle on for your shooter, and what speed control algorithm did you use?

Re: Gearing up two cims?
 

We're looking at using 2" belt pulleys with belts around them as a linear shooter and want to use 2 mini cims to augment our max output speed

Re: Gearing up two cims?
 

Honestly, if you are using such a small pulley, you could try something with a small (or no) reduction off of a faster motor like an FP or RS-550. The power difference isn't too noticeable in a flywheel and you will have a less frustrating time designing your shooter.

Re: Gearing up two cims?
 

Yeah, I'd definitely recommend considering gearing down an FP (or similar) rather than gearing up a CIM.

We used a single FP with a 4:1 or 5:1 banebots planetary to shoot nerf balls about 30' back in 2006. So long as you keep them moving at a decent RPM most of the time they don't overheat.

Jason

Re: Gearing up two cims?
 

Interestingly enough, the FP motors aren't legal this year. New miniCIM and BAG motors make up for them though.

Re: Gearing up two cims?
 

The Banebots RS-550 is very nearly a drop-in replacement for the Fisher Price motor, with the exception of the output shaft not being knurled, and the motor having a little less power.

In Logomotion 2011, we drove our entire arm off a single Banebots RS-550 motor, appropriately geared down (about 750:1).

Re: Gearing up two cims?
 

I'd have to say that I wasn't there for when the robot was programmed so I don't know what kind of speed control algorithm was used. However we did have a CIM that was operating less than optimal. It was geared up and I would guess the speed was closer to around 6-7k rpm. With the final shooter wheel running at about 8-9k rpm (perhaps even faster). I honestly don't remember the gear ratios but this was the estimated speed when we built it.

- Andrew

Re: Gearing up two cims?
 

If you're still looking at using a CIM, AndyMark is working on a product called the spin box that should be available in the next few weeks that is designed for gearing up CIMs. Andy and I discussed it over lunch ;)

Re: Gearing up two cims?
 

Do you happen to know if this SpinBox has a shaft for an encoder?