HELP Please: New Ballscrew Installation

[vacpress]

I am certain this has probably been covered, but I would like to ask some advice about an immediate purchase.


Mcmaster.com (see page 1009)

McmasterCarr has 5/8 ballscrew listed for $1.27/inch. The ballnuts with a flange cost around $50.00. This all seems very economical untill you see that the support bearing blocks are ~$270.00 each and you need to machine the screw to fit. This adds ~$700. The question, of course, is 'How do I avoid this extra $700?"

Like many of us, Ive got a beatup enco metal lathe and manual mill in my shop, as well as some inexpensive guages and calipers, etc.

Advice? Please! I keep almost ordering a screw to experiment with - a rather expensive proposition.

Robert

[DRD]

Go to rockford ball screw, they will custom make ball screws that will bolt into your machine, and will include a new yoke in the kit for $800.00. I am glad I went this way on my cnc mill conversion.

[mxtras]

The big money is because of the bearings and yes - there is a way out. The higher precision bearings are very expensive.

This may seem unrelated at first, but dig around here a little - somewhere in the following thread (I think around post #8) there is pertinent info on how to get pretty darn good precision from relatively inexpensive support bearings.

http://www.cnczone.com/forums/showthread.php?t=16538

Scott

[vacpress]

Well mxtras,

Thanks. That was informative. It has made me VERY afraid of ballscrews. I do beleive I am going to go with rack and pinion! The only commercial machine I have experience with was a R&P - it was very accurate. It was very fast. It had smaller motors than me..

Stupid angular contact bearings and whatnot!!! I suppose I will now just be frustrated looking for accurate bearings to hold all my pullys and whatnot in place...

There is such a huge amount of info to learn when it comes to this stuff, and the costs are signifigant...

Is there any hope in using something like 4 stacked abec-7 rollerblade bearings and preload the 2 stacks against each other?