[Andy A.]

I would suggest that you utilize the provided gearboxes. They are, on a whole, pretty decent.

If the final output is not close to your desired ratio, you can open the transmission (remove the motor and carefully pry all the plastic tabs out. It can be a chore but is possible) and replace the shaft through the second stage which is a significantly faster ratio. Inside the case, you will likely see a whole bunch of white plastic gears of increasing size and covered in grease. Spin one to see how things work; It's a pretty clean layout. The shafts running through the gears are steel hex shafts of sizes I do not know. I do recall that getting the correct hex stock was easy enough, so it is a stock (metric I think) size. By replacing the hex shaft with a longer one and modifying the black casing to allow it to extend out, you then have a new output shaft at a much higher ratio and a transmission that is pretty reliable. This does require a lathe to turn the new shaft down in certain places, so make sure that someone on your team knows how to turn hex stock- it's a little scary if you don't know what your doing.

That second stage is a pretty good ball park speed for running rollers. From there you can adjust your gearing with different size timing belt pulleys or chain sprockets etc.

Of course, you do not need to use the black transmission. Because the transmission is not considered integral to the motor, it is permissible to not only modify it, but to remove it entirely. Doing so will leave you with just the motor, so make sure you are up to manufacturing a transmission if you decide the stock one will not work for you.

Connecting a shaft to the stock gearbox most effectively and easily requires a special adapter that is used in the units original employment. These used to come in the kit, but you must now purchase them. I do not know how, but I think that Dr. Joe has good info on that, among others.

Sorry that I don't have any specific measurments or a white paper for you. I think what I've related is a decent use of the transmissions, but other more learned then I may think it a terrible idea. I would suggest you listen to what they say if they call a foul on this idea.

-Andy A.