we are pretty much in the experimental phase of our mini bot. when we went to put it on the pole, although it was tightly secured, our motor twisted inside its’ motor mount and unaligned our gear with our wheel. now we have to go back and find some way to secure this properly. we are thinking of using a set screw. along with this I would like to say that the tetrix resource kit has given us nothing but trouble in building this mini bot.
How are you attaching the motor in the mount? First time we tried, it wasn’t held in the bracket at all. What you do is take the bracket and pry it open a little and place the thickest part of the motor in the bracket, then tighten the bolt.
The Tetrix clamshell bracket is sized to grasp the circumference of the gearbox. The mounting screw does double duty for holding the clamp to a beam or plate and tightening around the gearbox. The screw on the other end only holds the bracket to the beam. You need to put both screws in place first. Insert the motor gearbox first since it’s got a rounded end that goes in easier than the other way. Then put your drive gear on the output shaft. You can now grasp the barrel of the motor and twist it so that the motor’s gear meshes with whatever gear you’re driving. Once you get a good alignment, you can tighten the clamp end of the bracket. I’m using the nut on the outside or top of the clamp with the cap end of the screw on the inside of the beam or plate. That way a wrench or nut driver has no trouble getting a grip on the nut. If you cannot get it tight enough, there is a chance you have stripped the threads on either the nut or the screw. These are only #6 hardware and practically all FRC team members are strong enough to over-tighten them.
HTH - good luck
A word of caution…be careful you don’t over tighten the clamp when you are securing the motor/gearbox. There is only a very small clearance between the gears and the inside of the gearbox housing and it doesn’t take much compression to collapse the housing onto the main gear inside ( as my kids found out the hard way).
Seconded. I forgot to mention that the clamp is best around the far outer edge of the gearbox so that major compression is borne by the front end cap. Clamping the gearbox too tightly in the center can have the adverse effect on gears as mentioned.
Has anyone tried roughing up the inside of the clamp or the shell of the gearbox? An increase in friction here could be a good thing. Simply abrading either or both surfaces with 80 or 100 grit sandpaper might reduce slippage and lessen the clamp pressure requirement.
There is another mounting option, but it is not “in-system” for Tetrix. There are two M3 holes in the face of the gearbox (at least on my motor) that could be used as a mounting method once you know the exact axle locations. Again, care will be required to avoid conflict with the internal gears and whatever mounting screw you insert. Maybe precise measurement will be worth the weight reduction of ditching the “heavy” clamp?