pic: One-day Minibot

[Teched3]

I personally don't like to have to make shafts for all the spare motors, especially for these motors and the task at hand. I try to use motors as they come out of the box. Replacement is much easier. We use double set screws with a Loctite adhesive that is advertised for polycarbonate. In addition, since the motor shaft does not come through the back of the motor, you risk damaging the rear bushing pressing your drive shaft onto the motor shaft. If you still insist on removing the pinion gear, I suggest making a push plate that will go in the area between the back of the pinion and the front of the motor housing. However, you still have the problem pushing the drive shaft onto the motor shaft. I would rather use that same push plate to press the drive shaft directly onto the pinion gear.

Nice design - quick build and effective. However, by St. Louis, consistency with deployment and dependability are likely going to be the deciding factors. You can only lighten so much, push the amps only so far, before you plateau with the minibot design. We're saving our best for St. Louis.

[sanddrag]

Originally Posted by Teched3

If you still insist on removing the pinion gear, I suggest making a push plate that will go in the area between the back of the pinion and the front of the motor housing. However, you still have the problem pushing the drive shaft onto the motor shaft. I would rather use that same push plate to press the drive shaft directly onto the pinion gear.

I did exactly that to remove the gear. Did it years ago with FP motors too. I never considered a press plate to push a shaft directly on the gear, without loading the motor shaft. Great idea! I'll have to keep that one in mind.

I was a little worried about pushing the shaft, when it doesn't go all the way through the motor, but it appears to have turned out okay.

[Mr V]

Originally Posted by sanddrag

I did exactly that to remove the gear. Did it years ago with FP motors too. I never considered a press plate to push a shaft directly on the gear, without loading the motor shaft. Great idea! I'll have to keep that one in mind.

I was a little worried about pushing the shaft, when it doesn't go all the way through the motor, but it appears to have turned out okay.

There are pinion pullers designed specifically for removing pinions. Pulls it right off easily w/o and damage and only costs a few dollars. However we removed them a couple of different ways w/o any damage to the rest of the motor because we didn't want to wait for the mentor who had the pinion puller at home. The simplest method to do it w/o a pinion puller is to cut a slot slightly wider than the shaft in a plate that is larger than the motor. Then slide the motor on the plate, support the plate with the open jaws of a vise or some blocks and use a small diameter drift to drive the motor out of the pinion. Be sure to have someone ready to catch the motor. Grinding or filing the pinion most of but not all the way to the shaft will allow it to slide off easily also.

No worry about pressing the new "wheel" on the shaft when I did autopsy on motors with broken tabs and burnt inductors I found out that the CE bushing is a ball end type bushing fully supported by the brush plate. So as long as the amount of force is not great enough to bend the motor shaft and you support it on the bushing bump on the brush plate and not the case or terminals the motor shouldn't be damaged.