Machining Ball screw ends

[Ferrari2007]

I would like to better understand how to go about specifying machining requirements to a machinist for my ball screws. I will be purchasing my ball screws new and need to have both the end blocks and motor ends machined.

I already have my end blocks and ball nuts. I will be using a 1" 0.5" lead ball screw.

Are the ball screws essentially machined on one end the same diameter as my motor shaft with a flat for a coupler?

On the end block side, is this machined with a taper to match the block and threads?

I have not yet selected my motors, any suggestions on motor size? This is for a 4x4 table doing woodworking.

I'm in the Kansas City area, if anyone can suggest a machinist who is familiar with this process.

Thanks

Kevin

[thuffner3]

Hi Kevin,
Depending on where you purchase your ball screws from, the company should be able to accomidated your machining needs base on your desired coupling.
I purchased mine from the Reid tool co. Very good people.

Peace
Neil

[Ferrari2007]

Neil,

Thanks for the input, I will give Reid a call. I had been ordering most of my supplies from McMaster, they may offer the service too, but I have not asked them.

Thanks again for the suggestion.

Kevin

[Cartierusm]

Try Roton.com they rock. As far as machining the ends of ball screws this is how I did it. First off if you're using a 1" ball screw you'll need to find a coupling to go from the motor to the ball screw. So let's say you're using Nema 34 motors they usually have a shaft size of 1/2" and then you'll want the other side of the coupling to be close to that size as have a coupling with a large variance of hole size is hard to find. So what I'm saying is with a 1/2" motor shaft I would have a coupling with 1/2" on both sides and have the end of the ball screw machined down to 1/2". On the other end I have it in a bearing so it can rotate. I would do 1/2" as well. So I would have both ends of the ball screw machined to 1/2" and about 1 1/4" on the bearing end (to allow it to go through the bearing and then have a stop collar after that). On the motor side I would have it 1 1/2" long to make sure there's enought length. You can always trim it off with a grinder if it's too long. Now the big part is you need to find out from who ever you buy the ball screws from is if they are hardened and if it's surface hardened. I think most are surface hardened which means it has a very thin coating of hardened steel. Once you get past that it's easy machining as it's just regular steel. Now most machinists will bock as machining surface hardened steel but it comes off pretty easy. What you want to look for is a machinist with a bag of old used carbide inserts for his lathe so he can go through a couple of throw away inserts as he cuts the hardening away.

[Ferrari2007]

Thanks for the input. I have looked at Roton and contacted them, they do not provide machining services. I am finding most places that sell them do not provide machinig services. I will most likely need to find a machinist locally.