# G0602 Compound Tuning



## Troutcreeks (Oct 26, 2022)

Hi, I've got a Shop Fox equivalent and since day one I can not get the compound to run back and forth easily. As I approach either extreme it tightens up. I have replaced all of the internals and adjusted gibs to no end with no resolution. Any thoughts? Thanks


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## benmychree (Oct 26, 2022)

Scraping is the answer to getting smooth movement on any machine slideway, the sliding surfaces need to be straight and well fitted to achieve that end, about all that is needed is a scraper, and a reference surface such as a surface plate and a dovetail straightedge and some marking medium, such as Prussian blue, and Oh! a bit of study and/or instruction. Connely's book "Machine tool Reconditioning" is available from Rich King.


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## Huub Buis (Oct 26, 2022)

I have a HBM BF290 lathe that had such an issue. After some investigation I found that the handle that holds a trust bearing was off center because the end machining of the spindle was off center. The manufacturer had tried to fix this by drilling the hole for the handle oversized and added 3 grub screws to center the handle. Centering the handle using these grub screws fixed the problem.

Remove the spindle and adjust the gibs without locking the screws with the nut. Then check how far you can move the compound slide. If it still tightens up, there is probably some wear. Loosen one of the gib screws to find out where this wear has taken place. Check the gib and all machined surfaces at that position for damage or wear.

If the locking is not caused by the gibs, then place the spindle back. Loosen the spindle nut bolt and move the compound slide completely towards the handle. Then tighten the spindle nut bolt. You probably have to remove the compound slide for this.

If you have adjusted the backlash of the spindle nut by adjusting the 2 spindle nut screws, then remove the screws and check if the problem is solved.

You can only adjust a grub screw if the gib at this point is pressing on the slide (not air).


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## fitterman1 (Oct 26, 2022)

Measure the dovetails for parallelism accurately so you know if there is any taper and adjust if necessary.
Check your gib and see if the adjustment of the grub screws is lifting the compound body.
This was the problem on mine.


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## Mitch Alsup (Oct 26, 2022)

benmychree said:


> Scraping is the answer to getting smooth movement on any machine slideway,



This, BTW.


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