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Machining a ball screw...
prawnabie - 18/5/17 at 12:59 PM

Hi all,

I have 4 chinese ball screws (ooh errr!) that are just a nats wotsit short of being a decent fit in a 12mm pillow block bearing. I am toying with the idea of getting the ends of them machined down to 10mm (I assume they are hardened) and using 10mm pillow blocks instead, is there anyone on here in the south Birmingham area who can do this for me, obv beer tokens waiting!!

Thanks,
Shaun


nick205 - 18/5/17 at 01:32 PM

If the parts are hardened then I'd have thought they'd need to be ground down rather than machined. I guess doing so may even alter the hardness of the part and in turn affect the durability of it.

Maybe source alternative parts for the job in hand?


v8kid - 18/5/17 at 02:40 PM

Are you sure its not imperial 15/32" ?


bart - 18/5/17 at 03:36 PM

Couple of answers. If it's just a nats four skin then put then in a lathe and polish them down with emery .

Alternative 2. Put the ball ends in freezer if possible .and warm the blocks up to about 50deg.that should do it.

Alternative 3. Heat the ball screw end up and let it cool down in s bucket with dry sand in .so it cools slowly or a heat blanket. This will not affect the ball screw it's self. Done it several times . Best done with an induction heater if possible get to cherry not yellow .blow touch is ok but tends to heat a lot more than you want . If your near bolton I make induction heaters and I'll heat them for you. U2u me

[Edited on 18/5/17 by bart]


prawnabie - 21/5/17 at 09:51 AM

Hi all,

Sorry I have you some mis-information!

The bearing ID is 12.02mm and the ballscrew shaft OD is 11.50mm. So I was thinking of getting the top an bottom machined to 10mm and buying the appropriate pillow blocks.

The only alternative I can see is cutting up an old coke can and sleeving the screw where the bearing sits, it only rotates 1-2 degrees every minute and there are grub screws on the bearing to hold the "sleeve"

I have 4 of these and each one has a bearing top and bottom (there are from the z axis of a 3d printer I am building).

Thanks,
Shaun


MikeRJ - 10/6/17 at 07:11 PM

Could you go up to a 15mm bearing and get some simple sleeves machined?