Re: [CAD_CAM_EDM_DRO] Re: Backlash effect on Part accuracy

turbulatordude wrote:

>>That's good to know. As long as we're on this topic, what can I do to
>>reduce backash on the mill I just got? It already has ballscrews
>>
>>
>but my
>
>
>>guess is that they're pretty worn out, 10 thousandths in Y and 3 in X.
>>Can I buy oversize balls, adjust something, get new screws, or what?
>>Michael
>>
>>
>
>I think you need to determine the source of the 'backlash'
>
>If the balls are worn, it will be relatively constant across the
>length. if the screw is worn, the slop will be more pronounced where
>the wear is.
>
>

Differential wear is a common phenomenon with Acme screws, but is very
unusual
except in the most heavily-used production machines with ballscrews.

>But, another possibility is the screw end. if the angular contact
>bearings are not adjusted properly, the play in those bearings might
>be the problem.
>
>

This is the most likely source of .010" of backlash.

>And lastly, if you dual ball-nuts to make an anti-backlash ballscrew
>nut, that may need adjustment.
>
>

Most ballnuts made since the 1960's are not adjustable.

Jon