CNC Conversion - Ballscrew Questions

[Deviant]

Looking for the stats on the ball screws for a HF cnc conversion. Length, diameter, pitch etc.

Also looking for prefered cheap suppliers, for the ballscrews and the load ballnuts.

Any other info on this portion of the conversion would be great.

Thanks

[CNCadmin]

I used 5/8" ball screws from Roton.

[Deviant]

What was the price tag for the ball screw, ballnut, and mounting flanges.

Also what was the over all length needed for each of the 3-axis on a HF mini mill.

Thanks for the prompt response.

[Bubba]

I also used Roton 5/8 ballscrews and made my own pre-load nuts. I bored the right hand X end bearing block and the Y bearing block to accept 12x32mm angular contact bearings. The left end is a fabricated mount for the servo and a 12x32 deep grouve bearing.

Some of the details can be seen on my web page:
http://bellsouthpwp.net/A/r/Arts_home_page/cnc/
Bubba

[t_dig]

Hi Paul,

You mentioned that you got your screws and nuts from Roton. I am wondering if you know the part numbers?

[Bubba]

t_dig
I'm not Paul, but the ones I used are:
59321-60 Ball Screws -- , Thread Size: 5/8 x .200 x 60, Hand: RH
19193 Ball Nuts -- , Thread Size: 5/8 x .200, : - , Hand: RH , Type: 2, Style: Square, Thread Size: .938 - 16

Also, even though I single point threaded the nuts, I got a tap from MSC to chase the threads and it is:
4848693 15/16-16 Tap $30.19


Hope this helps.

Bubba

[CNCadmin]

Originally Posted by t_dig Hi Paul, You mentioned that you got your screws and nuts from Roton. I am wondering if you know the part numbers?

I got the screws and balls from Roton 317-821-4400 the part numbers are
59321-36 ball screw 29.95 ea
19193 ball nut 19.40 ea
to make them pre loaded 9.65 ea

[t_dig]

One more question. Are the actual screws just threaded end to end or have you done or had Roton do some machining on them. The reason that I am asking is that I am not real sure what kind of end bearings, and nuts etc. to use. I am trying to conver a Mill/Drill that I purchased from a guy.

do you guys have any pictures of the whole screw, nut, end bearings combinations?

[Bubba]

t_dig,
The screws I got were plain and I had to turn down the ends (actually did the hard case with a die grinder set up as a tool post grinder in the lathe) and then did the threading 7/16-20 for lock nuts. Used 40 d angular bearings on the ends except for the right end of the X axis and that is just a deep grouve. See my web site as noted above for more ideas.

Bubba

[8SECNOTCH]

Originally Posted by CNCadmin I got the screws and balls from Roton 317-821-4400 the part numbers are 59321-36 ball screw 29.95 ea 19193 ball nut 19.40 ea to make them pre loaded 9.65 ea

Just picked up a mini mill myself as Homier was having one of their traveling tool sales local to me this weekend. Still paid the normal 399.+ tax but saved the shipping . Really knew ahead of time that I needed a much bigger machine but this is just going to be something to learn on for a few months and the price was right.

Anyway - I want to do the ball-screw conversion as well. My plans as of now are to CNC the machine down the road but for now all I wanted to do is covert to inch & get a power-feed set-up.


1) I'm thinking that I can still use the ball screws manually?

2) I do not have a lathe so another question would be:

- IS ANYONE INTERESTED IN PERFORMING THE NEEDED MODIFICATIONS TO THE SCREWS FOR ME FOR SOME $$$?

If not / or maybe someone might be interested in some "trade labor?" I have $80,000 worth of top-of-the-line 3D CAD software on my Home System as I am a Contract Design Engineer and can model-up just about anything that you can dream-up as long as dimensions / constraints are supplied - just a thought for ya guys whom I may be able to help out as well.

Either way - I'm just getting started in machining so I am really quite wet behind the ears and really want to get this mini-mill ball conversion going right away.

Also - I have some smaller aluminum parts that I modeled-up which I need produced via CNC. Maybe some of you is interrested in looking at them?

IF ANYONE IS INTERESTED PLEASE GET BACK TO ME @ snakehorse1@ameritech.net

Thanks - Rob

[Bubba]

8secnotch
Per your item 1:
Fraid not! The force of the cutter on the table will impart motion in the wrong direction:{( That is to say, you can back drive a ball screw by applying a force to the end of the screw. Not good for manual cutting.

Good luck and hope you enjoy your cnc machine.

Bubba

[ESjaavik]

@rob: What Bubba wrote is absolutely a concern. But you can take care of it by re-introducing the friction at the handwheel. It would only make sense with preloaded nuts, since just using ballscrews to get rid of friction then re-introducing it is waste of money. But if backlash elimination and CNC preparation is what you look for, then it will work. A power feed may also introduce enough friction that it will solve the problem.

But what if you find out you will go for a bigger and more rigid machine before converting to CNC? On such machine it may be difficult to recover that extra cost when selling it.