# Mini lathe cross and compound slides rock during facing



## redvan22 (Apr 28, 2019)

Hi,
I have a Microlux 7x16 mini lathe and although the gib adjusting screws on both the cross slide and compound slide have been adjusted so they feel snug to me and still allow precise and controlled movement, when facing and approaching the center nib, the slide rocks and goes under the nib. Not sure which is rocking; the compound or cross as I have tried to manually 'rock' both and can't.

I have tried tightening the gib screws to eliminate the 'rock' but then controlled adjustment goes out the window because I need a wrench to turn the feed handle. 

I know the tool point is centered vertically because I have lined it up to both a center drill in the chuck and a dead center in the tailstock.

I think my issue is the same as in an article I read a while back where the gib key was taken out and trued but I don't know where I read it nor do I recall much of the details of the process.

Any suggestions will be greatly appreciated.
Mike.


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## redvan22 (Apr 28, 2019)

I FOUND the article i had read:
http://www.mini-lathe.com/Lapping/Lapping.htm


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## T Bredehoft (Apr 28, 2019)

Is it possible that the gib key is plastic, not metal? Replacement metal keys may be made. They take all the 'rock' out.


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## markba633csi (Apr 28, 2019)

Could be a couple of things: possibly some warping in the cross slide or compound, poorly machined or warped gib strips, a problem with your tool post/tool holder, or extending the tool too far from the carriage so that the carriage begins to tilt upwards at the opposite side
Also what Bredehoft said
Mark


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## redvan22 (Apr 28, 2019)

Tom, 
No, not plastic. Metal but as Mark commented, they are warped. I took the cross slide gib out after reading the article I re-found and with a straight edge against the gib, there is a gap in the middle and on the other side, a high spot in the middle. (This also explains the tightness at one end until I get past a certain point.)

I'm going to lap it along with the compound slide gib as per the instructions in the article.

Thanks for the very quick response.
Mike.


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