Minibot Motor Press Fit
 

I'm trying to press fit "something" to the Tetrix motor with transmission removed. The shaft appears to be 1mm in diameter. What size hole should be drilled / reamed into my part in order to nicely press fit onto the motor shaft?

Re: Minibot Motor Press Fit
 

1.00mm diameter? or something else?

Generally a couple thousandths of an inch interference makes a good press fit. But it depends.

Re: Minibot Motor Press Fit
 

I agree with Jim, .001"-.002" per inch of diameter, so your tolerance is pretty small. What material are you pressing on? The softer it is the more press it can tolerate.

Re: Minibot Motor Press Fit
 

1.0mm? Our motor shafts are 2.5mm in diameter... (0.0984 inches)

We were able to press fit a 3/32 inch (0.0938 inch) hole in a 6061 aluminum rod (.25" OD) onto the shaft without difficulty. Just make sure you support the back of the motor where the shaft "nub" is so you don't pop out the other side :)

Re: Minibot Motor Press Fit
 

Jared is right, it is a 2.5mm shaft. Be careful when you're press fitting something on there, I can think of other ways to accomplish what you're trying to ultimately do. Press-fitting may or may not be your best option :cool:

Re: Minibot Motor Press Fit
 

As the others have said...The shafts are 2.5mm. I always try to use a micrometer to measure the exact diameter of each shaft and ensure they are very close to each other. When you are dealing with smaller pieces and press its important to be as accurate as possible.

-Brando

Re: Minibot Motor Press Fit
 

I used a #41 drill bit which measures .0960 inch. my calipers measured the motor shaft at .0980 in. we are most likely pressing the same "something" onto the motor.

Re: Minibot Motor Press Fit
 

I just got the 1mm number off of a flawed CAD model. Thanks for the clarification.

Re: Minibot Motor Press Fit
 

I can't - the shaft seems too small to affix a setscrew to. Is it not?

Re: Minibot Motor Press Fit
 

Instead of going with a set screw you could use a "clamp on" style thing you want to attach to the shaft.

~DK

Re: Minibot Motor Press Fit
 

I didn't know clamps came small enough to rigidly fix onto a 2.5mm shaft...

Re: Minibot Motor Press Fit
 

Red loctite can also be used to secure press fits. We have it in a custom gearbox securing a RS775 to a tough box shaft and it has worked great.

Re: Minibot Motor Press Fit
 

Can one use such devices on the minibot?

Re: Minibot Motor Press Fit
 

If you have Loctite 638, then I would recommend that over Red (271) for press fitting something onto a motor.

Re: Minibot Motor Press Fit
 

I was going to mention that, it is actually made for press fitting two smooth objects together, oddly the local autoparts stores here didn't sell it even though it is often used for bearings in cars. So we settled for red loctite which works in low torque situations (like our lifter)

But similarly, I am not sure 638 is technically allowed on the minibot where-as Loctite designed for thread-locking is.