Mini mill & ballscrews

Advert

New Replies

Report Bug

Help/FAQs

Mini mill & ballscrews

This topic has 9 replies, 7 voices, and was last updated 10 February 2020 at 22:40 by Enough!.

Viewing 10 posts - 1 through 10 (of 10 total)

Author

Posts
9 February 2020 at 19:56 #451461
Iain.S
Participant
@iain-s
Hello All

I've recently bought a Clarke CMD10 (Sieg X1) mini mill to play with in my retirement. Yes, I know I could have got bigger & better, etc, etc, but for the small stuff I want to do, this is a good starting point. Upgrades will follow but I'd rather learn & become more confident with basics first.

My first issue is with the agricultural leadscrew arrangement on the X & Y. Ballscrews appear to be the way to go but the 12mm ones won't fit and 10mm ones are as rare as an honest politician and cost the same as a third world debt!

On such a small machine, is there any valid reason (not opinion) preventing the use of the more common 8mm ballscrews? I know a 12" deep cut in one pass will be out of the question and I can live with that but could a supported 8mm screw be man enough for general light work & small pieces?

Iain.S
Advert

9 February 2020 at 19:56 #10069
Iain.S
Participant
@iain-s
9 February 2020 at 22:35 #451491
David George 1
Participant
@davidgeorge1
I have a slightly larger mill a Chester 16V and I have changed the z Axis for a 12mm ball screw but i would have used a larger if i could have fitted it in. I think you would have problems with 8mm ballscrew being very light. Usualy the axis nuts are adjustable with a screw to close the nut and reduce back lash. Perhaps you can fit thrust bearings to the handwheel end to reduce any play there.

David
9 February 2020 at 23:03 #451495
Enough!
Participant
@enough
Previous discussions here and here may be helpful
10 February 2020 at 07:05 #451517
JasonB
Moderator
@jasonb
Is it a problem of rough feed or backlash that you want to change the screws for? If backlash as has been said adjust the split nut and spend your money on a DRO.
10 February 2020 at 07:28 #451524
John Haine
Participant
@johnhaine32865
As Jason says, plus fit ball or roller thrust races to the handwheel bearings. And see Mikes Workshop for many other improvements to the X1 mill.
10 February 2020 at 08:59 #451532
Russell Eberhardt
Participant
@russelleberhardt48058
Are you considering upgrading to cnc? If not I wouldn't fit ball screws as they will not stop the slide moving under load. They are reversible unlike normal lead screws.

Russell
10 February 2020 at 18:23 #451614
Iain.S
Participant
@iain-s
Many thanks for the positive responses chaps. They've been really helpful.

Upgrading to CNC level is a step too far at the moment, so I'll rule that out and stick with manual operation.

The main issue is as Jason suggests, with rough feed & backlash. I've played with the split nut block under the tables to try & reduce backlash but find that it's a very fine adjustment between a sloppy bed & binding screw which is why I thought about ballscrews.

Having scanned the various posts suggested (plus a few others), I think I'll do as you recommend and go with installing bearings & thrust races to the handwheels. A replacement, longer X axis bed was planned anyway, and it'll need a longer screw so I'll start with that. Will order a boring bar & replacement bearing block to play with. Arc is going to have a regular customer over the next few months .

A belt drive conversion kit (mbbilici) & DRO's will be next on the list.

Once again, many thanks.

Iain.S
10 February 2020 at 19:42 #451626
Ex contributor
Participant
@mgnbuk
If not I wouldn't fit ball screws as they will not stop the slide moving under load.

Screws are provided to move slides. Clamps are provided to stop slides moving under load.

Nigel B.
10 February 2020 at 22:40 #451645
Enough!
Participant
@enough
So you fit a ball screw which may allow the work to be dragged into the cutter because the helix angle and friction aren't enough to prevent it. Then try to control it by tightening the gibs?

I wouldn't but to each his own.
Author

Posts