Re: Ballscrew Slop Question

--- In CAD_CAM_EDM_DRO@y..., Hugh Currin <currinh@O...> wrote:

> John:
>
> At 04:29 PM 2/13/01 +0000, you wrote:
> >Hello All, I just installed ballscrews on my Bridgeport mill, in
> >preparation for a CNC conversion. They were purchased from Hi-Win
> >Industries. After installation, I noticed that there is about .002-
> >.003 slop in either direction on the X axis. (the Y seems OK) I

have

> >been told that my bearings that are in the left side end cap might

be

> >at fault.
>
> I recently installed Rockford ball screws on my Bridgeport size

mill. I

> have some .002 backlash in the Y. I had about this in the X but

worked

> with the alignment which eliminated it. I convinced myself that if

the

> nuts and bearings are in very good alignment the backlash was much

better

> or was eliminated. I still think this but don't really know why it

would be.

>
> I need to build new bearing blocks for Y and the right end of X to

mount

> stepper motors. I figured I'd take the time to align everything

when these

> are in place but not expend the effort until then. So, I can't

confirm

> this yet. But, you might spend some time aligning stuff and see if

it helps.

>
> This after adjusting the bearing "pre-load". The outer race needs

to be

> held to the housing and the inner race held to the lead screw

without

> play. If you look carefully at the bearing blocks or a drawing of

this

> it'll become obvious how the bearings are held. I suspect the

bearings are

> OK and I'd do quite a bit of fiddling before I spent the $ for new

ones.

>
> Please let me know if alignment gives you any gains in backlash.
>
> I for one are interested in reading and seeing how you are putting

together

> the CNC portion. Please keep us up to date. Thanks.
>
> P.S. If you do any manual machining watch yourself. I've been

smart (or

> lucky) enough to lock axes I don't want to move. But have broken a

couple

> of tools because my hand is calibrated for the acme screws and

tends to put

> too much torque into the handles attached to ball screws. Much

smoother

> motion though. :-)
>
> Hugh Currin
> Klamath Falls, OR

Hi Hugh, Thank you for the hints, I will give them a try. I will
gladly keep everyone posted on my progress, I am buying each piece at
a time as money permits... I already have the drives (gecko) I will
be looking at motors soon. I am also looking for a power supply, at
least 50 volts at 10 amps, anyone know where I can get a power
transformer? John