Refitting a Grizzly G9972Z (Yangzhou Super Machine Tool Co CQ6128)

ohland

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Things finally slowed down, my dog sprained her left "wrist", and we are waiting for a new oil furnace to be installed. I had to strip down the 11x26 lathe down to the bed so the furnace installers can get to the furnace....

There are a few bothersome things. About ten of the oil ball fittings have failed with the ball dropping down a little or entirely gone. The gearbox leaks badly, holding a fill for maybe two days before dropping out of the port (but still enough to make a mess). Dislike the 150 RPM slowest speed (extreme thread cutting, anyone?). So over the next few months, I intend to refit this G9972Z so it works better.

Plenty of mods. I like the retracting toolpost for threading. DC motor retrofit. Reverse tumbler. Just got to get there. Then I can get to my SIEG X3....
 
A device::

And fixing it:

There is another guy who built his own version of this 4:1 reduction but I can't find it right now.

This device allows you to run the lathe at full speed, or at reduced speed with a small reconfiguration.
I have been contemplating making one to be able to run my lathe lower than 70 RPM.
 
I have seen where folks used a planetary gear reducer, it seems compact compared to the belts and pulleys in there now.

Just saw "lift up" or "flip up" thread tool. ChiefRex96 on YouTube. Now this is darned near genius.

 
On my mill I replaced most of the ball oilers with zerk fittings and use a Bridgeport style oil injector to lubricate. Much better getting oil where it needs to go == Jack
 
Pull Gear speed reducer, 7:1, the G9972Z would turn at @ 21 RPM... wow...
 
On my mill I replaced most of the ball oilers with zerk fittings and use a Bridgeport style oil injector to lubricate. Much better getting oil where it needs to go == Jack

How to pull the press fit oilers? They are brass, and I think it would be like pulling a stuck case out of a die. Tap with a thread forming tap (no chips) and use a bolt, a washer and a 3/8 socket (most any size over bolt diameter would do) to pull it up...
 
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I could live with a max 500 RPM, so a fixed speed reducer would do...
 
While not the exact answer you're looking for, I built one for a Grizzly 1550, a 9X20 machine from Taiwan. It was several years ago, but might apply or be modified to your application. Try looking at:
http://www.hudsontelcom.com/9X20Gear.html and see if you could use the idea. Granted, it was for a much smaller machine, but you might be able to make it work. Depends on your spindle size and what size gears you can lay your hands on. There is no milling as such, everything was done with the lathe.

Conceded, it was to slow down a too high speed machine. If you have back gears already, it should slow the spindle to a crawl. Good, if that's what you need. A waste of time otherwise.

Bill Hudson​
 
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