Need help on my 957 backgear won't disengage

[Chris Hamel]

As I was finishing up today, I pulled the knob to lock the spindle to put my chuck back on. When i went to push in the knob, it won't go back in. It has happened before, but jiggling the spindle and popping the knob with my Palm has always done the trick. Not this time. The knob goes in about 1/4 " and I can see the back gear shift but that is it.

 

[Shiseiji]

I assume you put the feed reverse gear in neutral, are you able to disengage the bull gear so you can try rocking the shaft with a screw driver?
It's a minor PIA, but it is possible to adjust the back-gear rack using a pair of long thin screwdrivers. It's just tough getting hands where they need to be in the small head stock.

Scott Logan has posted some detailed instructions on the Groups.io board: https://groups.io/g/Lathe-List/message/146 can't remember if you have to join or not read it. Both of my 820's came with the back gear rack adjusted wrong. Some people have gotten creative and put a slot at the end of the eccentric shaft so they could rotate it, but I've managed. IIRC, it will rotate about one tooth so the trick is to have it not quite right and then as the shifter rack engages it will pull the shaft the one tooth to where it needs to be. Does this make sense?

Ron

 

[Bi11Hudson]

Most of my experiences for such were on larger machines, shipyard lathes and the like. Straight cut gears seem more likely to hang up like that than taper cut gears. Pressing on the "button" and rotating the chuck will usually suffice. In place of rotating the chuck, you can rotate the belt sheave.

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[Chris Hamel]

After signing up so I could read the post you sent the link for it makes sense. I had convinced myself that I was going to have to remove the collar on the back. Sounds like the trick is in getting the rack to catch on the right tooth when I put it back in.

 

[Chris Hamel]

It turns out my problem is related to the latch located right behind the knob. Took a screwdriver and pushed it in and knob went in. Maybe some oil is necessary.. if I had bent over and looked with a flashlight I would have seen. The drawing on the Logan users group really helped.