That's why so many Asian manufacturers copied the SM design.
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Lathe Stall
- Thread starter Beez12
- Start date
I believe the Utilathes actually is one step up from the “lead screw for power feed”: IIRC, the lead screw on the 9” has a key way machined the length of the shaft. There is a separate power pick-off gear in the apron for the feeds. In that particular case only would the lead screw threads not be worn by using the feeds. The Asian machines and other manufacturers may not have that key way.
Craig, maybe you can confirm the key way in the lead screw. It’s been a long time since I’ve had a 9”Utilathe.
Craig, maybe you can confirm the key way in the lead screw. It’s been a long time since I’ve had a 9”Utilathe.
Yup that's exactly how it works. The lead screw has a keyway it's entire length. There is a long keyed worm gear in the saddle that only comes into use when the PF is setup for longitudal feed or cross feed. There is feed clutch to engage as well. The lead screw threads and half nut are only used for threading.
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Alright fellas, back at home from work finally. Have this clutch dissembled again and followed robinhoods guidance on the fix. Now before I reassemble and try again and I wanted to make sure everything looks good. The only thing I see being an issue is the spring rig expanding beyond the diameter of the clutch hub when engaged (thus power transmission is being forced onto the ring and the the hub). Any insight would help!
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Welcome back!
The first picture, that is with the clutch applied as I can see the cam rotated. Does it force the spring ring out from underneath the friction material? Can you push it back under with the cam in that position?
The second picture shows everything tucked under - like I think it should be.
Have you tried with the clutch drum on to see what the spring ring does if you engage the clutch? Might be hard the see inside the drum, but would be nice to know what happens.
I wonder if the activation cam was shop made and needs the cam turned down to form a cylinder so it does not drag the ring with it, but rather only pushed against the shoes. Maybe it just needs to be pushed up a bit so that the ring does not ride on the cam lobes?
From a previous picture of the spring ring you posted it looks like it has been rubbing where the activation cam is. Do you see any scoring inside the drum? Maybe the shoes still make contact and the ring does not. It could just be because there is no drum constraining the shoes in that picture. Brake shoes on cars do funny things too when the drum is off; once all assembled, bits fall into place.
The first picture, that is with the clutch applied as I can see the cam rotated. Does it force the spring ring out from underneath the friction material? Can you push it back under with the cam in that position?
The second picture shows everything tucked under - like I think it should be.
Have you tried with the clutch drum on to see what the spring ring does if you engage the clutch? Might be hard the see inside the drum, but would be nice to know what happens.
I wonder if the activation cam was shop made and needs the cam turned down to form a cylinder so it does not drag the ring with it, but rather only pushed against the shoes. Maybe it just needs to be pushed up a bit so that the ring does not ride on the cam lobes?
From a previous picture of the spring ring you posted it looks like it has been rubbing where the activation cam is. Do you see any scoring inside the drum? Maybe the shoes still make contact and the ring does not. It could just be because there is no drum constraining the shoes in that picture. Brake shoes on cars do funny things too when the drum is off; once all assembled, bits fall into place.
Well it appears the spring ring protrudes when the cam is over rotated about 80 degrees. However for positive engagement that cam only needs to rotate about 20 degrees (which is the max rotation possible when the cone ramps into the expansion lever).
There was no scores inside the drum or anything concerning.
Guess I’ll throw it all back together and give it another run under power.
Previously when running the machine I had no clutch slip issues when running it in the back gear. Why would this be?
There was no scores inside the drum or anything concerning.
Guess I’ll throw it all back together and give it another run under power.
Previously when running the machine I had no clutch slip issues when running it in the back gear. Why would this be?
Nope, it’s just a gear selection in the headstock than decreases spindle rpm and increases torque.
That’s a good one. Have to think about that one for a bit...
That is good news. We like it when parts are not damaged and just need some adjusting.
Yup, clean, assemble, and give it a try. I would exercise the clutch without the motor running first. See if it engages properly. And more importantly, that it releases. Adjust if required. Then work your way up under power.
Slip stalling is better than breaking something. Mine breaks stuff before it will stall.
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Is the stall caused by the clutch slipping still?
Yup it appears to be, I’m just doing gradual clutch adjustments. All this is doing is giving me an excuse to buy another machine so I can modify some existing parts to make it work properly LOL
