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Things to Look for When Evaluating a Graziano 12S for Purchase

ACHiPo

Aluminum
Joined
Sep 16, 2012
Location
E. Bay, CA USA
What are specific tests, measurements, or validation to assess a Graziano 12S in addition to basic lathe evaluation (runout, way wear, speeds, feeds, etc.)? It's my understanding that the 12S reduced the problematic electromechanical clutches of the 12, but it still has two clutches plus a brake. What is a good way to assess whether the clutches and brake work properly?

Does threading on the 12S rely on rapidly switching between forward and reverse? If so what is a safe way to test to make sure it works properly? If not, what's the best way to test threading functionality?
 
I dont know if they all have it but there's a switch on the console with a leadscrew symbol for a threading brake.

Run it in backgear at its slowest. Turning the spindle off should engage the brake and stop it instantly. If not, the brake doesn't work. And if the spindle doesn't turn, then the clutches don't work.

Otherwise, you can thread using the half nuts. But they tend to engage a bit funky and it's easy to have it partially engaged and screw up the thread.

Also check that the speed control buttons function. And the speed indicator shows something. All the above can be done in backgear, so you dont have to worry about it running away on you if there's a chuck mounted.

There were 2 sets of pulleys available on these. The high speed set is about 500 to 550 at the lowest in high range. I don't remember what back gear is, maybe about 80 to 100. I'd have to look in the manual for the standard set numbers.
 
Thanks. I've confirmed that the Reeves drive buttons work, and the spindle and threading motion works, so it seems like that means the clutches are ok? Also I just noticed that it has a thread dial, so half-nut threading will work at least for English threads.
 








 
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