Dividing head backlash

[.RC.]

When you adjust the dividing backlash screw for the worm/wormwheel, should you adjust it so there is 0 backlash or adjust it so there is just a tad of backlash???

[SGW]

I'd adjust for as little as possible, but so it's still reasonably free-turning (no binding). Then assume there is backlash and always take up the motion in the same direction -- the usual routine.

[.RC.]

Trouble is the worm wheel has a tight spot in it...To get it free running I have to have a lot of backlash...

[CCWKen]

Take it apart and clean it or check for damage. As with any machine or equipment, the less backlash the better. Slop just adds inaccurate cuts or chatter.

[.RC.]

I have pulled it apart...The worm wheel does not appear damaged or badly worn but I have found where it is binding but the gear profile still looks OK..

I guess really I should make a hob of the correct size and run it around the worm wheel to clean up the bad spot...I have tried to find out what metric module the worm is but finding info on how to size a worm is rather difficult...Even Ivan Law's book is rather vague on worm wheels...

It is russian made so I know it is metric and to the best of my measurements it is either a 3, 2.5 or 2 module...

[phil burman]

I would also consider if the tight spot is possibly due to the bearing housing for the main gear not being concentric with the gear itself. Possibly much easier to correct.

Regards
Phil Burman

[mark61]

Try using a hand stone on the tight spot? Smoothing it out just a little might make a big difference!

mark61