[Colt4587]

Good Evening All!

I was hoping maybe somebody could help a new guy out. I have the PM-25MV, with the conversion kit from ProCutCNC/Automation Technology Inc. Located here for reference: https://www.automationtechnologiesin...ual-ballscrew/

I have the machine broken down and am going to begin the process of installing the ballscrews. However the bearings on there are "press fit." I've been told that you can sand them down slightly where they will go on easier. Does this affect accuracy at all?

If I did want to press fit them on, how would one go about that? I don't quite understand that part, as the Z and Y ballscrews would already be pretty much within the machine before you would attach the motor mounts? Another question, they came with two nuts on each threaded end. Do those actually serve a purpose, or are they there to just protect the thread?

One last question, do they need to be greased at all?

Thank you, and I apologize on what are probably easy questions.

[skrubol]

Bearings are hardened steel, I don't think I'd try sanding them. Normally they should be a light press fit. Those nuts should be what actually holds the screw/bearing/mount assembly together and may control the preload. You can cool (freezer) the inner part or heat (hair dryer, not torch,) the outer part to make things go a bit easier.
I think sealed bearings should be greased from the factory, but I'm far from an expert on bearings.

[Colt4587]

Thanks for the reply, they actually wanted me to sand the ends of the ballscrews down to fit through the bearings. Not sand the bearings themselves. Not for sure if it makes a difference or not?

[arizonavideo]

Have someone help you.

Put one end of the ball screw in a drill and have someone run it fairly slow, use a strip of sand paper on the bearing shaft to give it a light sanding.

Its fairly easy but the end the drill is on may vary well fall off so do it over something soft like the yard so you dont dent the end of the screws.