PM1127 motor seizes up when parting

Pcmaker

Pcmaker

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It slips a lot when I'm parting. Very annoying. Didn't have this issue before

What belt do I need to replace it with? Is it something I can get from AutoZone?
 
I thought it was the belt, but it's the motor. It seizes up when I'm parting. It didn't used to do this before. Anyone have any idea? It's less than 2 years old with very light use.

Using a freshly sharpened parting blade, 1/8" thick. Parting 1" 1045 round bar. Locked carriage, blade parallel to the workpiece

Even with very careful feeds it seizes up.

I used to use the power feed with no issues when parting.
 
Last edited:
what do you mean seize up? Does the motor slow (bog) down and then stop? Or does it stop suddenly? What type of motor is it - AC (1ph or 3ph?) or DC? Does it do it under other high load conditions?
 
Is this the PM1127VF? If so there may be an adjustment needed to the inverter drive parameters- I would contact PM
-Mark
 
it would stop completely like it doesn't have enough power to cut through.
 
Just a thought.
Is the Belt nice and tight?
Asking because it happened on mine the other night for the first time, it stalled the chuck on a parting off operation, I could tell it was the belt slipping.
My lathe isn't a PM
 
You should still be under warranty I would think.
 
I thought it was the belt slipping, but I took off the cover and it was the shaft of the motor that quit working and I could hear the motor humming like it's trying to turn, but doesn't have enough juice.
 
darkzero said:
Sounds like stalling to me, not seized, which is not uncommon.
Click to expand...

hence the request for clarification :)

I looked up the model. It has a 3ph motor and VFD, which I don't know much about, but that behaviour sounds like an overload (overcurrent really) protection is kicking in. Either the VFD is programmed incorrectly or you're doing something that is placing more load on the motor than it is allowed to provide. Parting is a high load operation, so is drilling large holes in hard material, taking really deep cuts etc. Could be that the end of your parting tool is no longer square to the work, say if it's been ground recently, as the blade is wandering and binding in the cut. Happens to me a bunch - if I pay attention I hear the motor starting to labour a bit so I can back the tool out. When you feed it back in you'll see it cut on the flanks of the cut.

Try some other high load operations and see what happens. If it reoccurs, it's an issue with the VFD/ motor. If it only occurs during parting, then it's something specific to that operation.
 
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