New bridgeport question

[Kody]

Secured myself a new to me bridgeport that needed a severe cleaning. Got it all broke down and I realized it has been converted to a ball screw set up and they are totally shot. Anyways, I’m definitely going back to the original style nut and I’m curious if the nuts will fit the rods or do I need to hunt down the original acme thread lead screws. Thanks!

 

[JohnEvans]

You will need the Acme screws also.

 

[Cole2534]

What does a 'totally shot' ball screw mean to you?

The nuts/screws on a manual machine can be fucking wasted, as in razor sharp acme threads, and still be accurate. Even more spr if the machine has a DRO.

 

[Kody]

What does a 'totally shot' ball screw mean to you?

The nuts/screws on a manual machine can be fucking wasted, as in razor sharp acme threads, and still be accurate. Even more spr if the machine has a DRO.

“Totally shot” to me means all those tiny ball bearings are now scattered about on my garage floor .

 

[Cole2534]

“Totally shot” to me means all those tiny ball bearings are now scattered about on my garage floor .

Yep, that qualifies.

 

[GregSY]

Are you guys sure you can't use an acme threaded rod with ball screw nuts?? Seems to me I can't think of a single reason they won't work together. They're both, ain't they?

 

[Nmbmxer]

One of my manual mills has ballscrews and I like using it a lot, climb cutting is great. Just lock an axis if it's stationary.

 

[Kody]

Thanks gents, I think I’m just going to try tracking down replacement nuts from whoever made the one I have already. I didn’t realize at first the bracket has been changed out to accommodate the ball screw set up therefore I’d have to replace that, both rods and buy the nuts and I’m not trying to spend that kind of money on things

 

[eKretz]

Are you guys sure you can't use an acme threaded rod with ball screw nuts?? Seems to me I can't think of a single reason they won't work together. They're both, ain't they?

Why don't you try it out and get back to us...

Thanks gents, I think I’m just going to try tracking down replacement nuts from whoever made the one I have already. I didn’t realize at first the bracket has been changed out to accommodate the ball screw set up therefore I’d have to replace that, both rods and buy the nuts and I’m not trying to spend that kind of money on things

You might be able to refill the nuts. Round up as many balls as you can and measure them. Get some more to replace any missing ones or even a full new set. Sometimes the balls are staggered in size, might want to ask the manufacturer if they can give you any advice.

 

[guythatbrews]

Why don't you try it out and get back to us...



You might be able to refill the nuts. Round up as many balls as you can and measure them. Get some more to replace any missing ones or even a full new set. Sometimes the balls are staggered in size, might want to ask the manufacturer if they can give you any advice.

Try this if the nut and leadscrew look fairly good. Sometimes the little recirculating tube can come loose or break allowing the balls to fall out. Can't really think of another reason the balls would fall out else. The balls are available in maybe .001 increments so while it's on the bench you can try bigher balls if youve got backlash. Of course you'll have to make sure it's not too tight at the ends of travel.

 

[Erich]

Ball screws don't use an Acme thread form. Idea is a non starter.

 

[michiganbuck]

Ball screws can be rebuilt, Threadcrafit here in Michigan is one source..
Might you measure and replace the balls.

 

[Kody]

Thanks for the tips. I just ordered standard lead screws and nuts to replace them.

 

[Superbowl]

Thanks for the tips. I just ordered standard lead screws and nuts to replace them.

That is not going to be cheap.

 

[Kody]

That is not going to be cheap.

It wasn’t going to be cheap any way I sliced it

 

[CarbideBob]

“Totally shot” to me means all those tiny ball bearings are now scattered about on my garage floor .

How did this happen?

 

[AlfaGTA]

The balls are available in maybe .001 increments

Try millionths.....For a real rebuild of a ball screw the pros often do it empirically.
Most machine shops don't have the measuring accuracy to spec the actual size of the balls needed
Repair shops test fit going in steps of 10 or 20 millionths.... There is no compression between ball screw and nut so going too large can
quickly kill the tracks in the nut or screw...Too loose and there is no point to going to a ball screw.
Cheers Ross

 

[rons]

If I had a choice, it would be ball & screw.

 

[Erich]

On a manual mill, the ball screws will back drive from the cutter loads. You will spend your life locking and unlocking each axis when you take your hand off the wheel.

 

[Doozer]

On a manual mill, the ball screws will back drive from the cutter loads. You will spend your life locking and unlocking each axis when you take your hand off the wheel.

Isn't that how most good manual machinists operate a manual mill ?

-Doozer