Pm-1340gt Crash -- Now What?

[wrmiller]

Feel for a notch worn in the drive belts. If the spindle stopped and the motor was going it takes very little time for the motor drive pulley to make a divot in the sides of the belts. Might be visible but might be hard to see. Rotating till you feel the spot and then checking that spot on the drive belts (part that is then on the motor drive pulley) you might find a wear spot in the sides of the belts that makes the belt jump once per revolution when it passes the drive pulley.

Parting can be intimidating, but to slow sfpm can be a bigger problem than to fast as far as the grabbing.

Yea, I won't go into how I figured THAT out...

 

[Reeltor]

I'm glad that nothing appears to be damaged. It's an instant heart in your throat when something like that happens.

As an aside, what is the break-in procedure on the lathe? Are you supposed to drain the oil, fill with Kerosene and run for 5 minutes then drain and refill with the recommended oil? This is the manufacturers' recommended procedure for the old mill (Van Norman) and lathe (Monarch) that I have. The kero will flush out any manufacturing swarf. What does PM ask you to do?

Again, glad you weren't hurt and the lathe is OK

reeltor.

 

[brino]

I had to choose between spending the money on the lathe or finishing the restore on my car.

Jason, Look at the good news: you crashed the lathe not the car!!!

-brino

 

[Coug67]

Reeltor -- I asked Matt at PM about break-in, and he said I might take it a little lighter on the cuts for a while, but no real break-in procedure was needed. The oil I took out was pretty black. I drained it last night, wiped out all the little bits of glitter with a rag, and put in some fresh. I'll run it for another couple of weeks and see if any more metal shows up.

 

[Coug67]

feed a little quick as opposed to slow.

Michael, I appreciate the advice. My stock was about 2.75" with a 1.625" center bore. I'm still REALLY new on all this. I've been reading and watching all the videos I can. I was very careful to square up the parting tool to the end of the stock. Sounds like a little more aggressive feed and speed may be the trick.

 

[Coug67]

Feel for a notch worn in the drive belts. If the spindle stopped and the motor was going it takes very little time for the motor drive pulley to make a divot in the sides of the belts. Might be visible but might be hard to see. Rotating till you feel the spot and then checking that spot on the drive belts (part that is then on the motor drive pulley) you might find a wear spot in the sides of the belts that makes the belt jump once per revolution when it passes the drive pulley.

Parting can be intimidating, but to slow sfpm can be a bigger problem than to fast as far as the grabbing.

I just happen to have a new belt. The reviews I'd read said the stock belt was pretty much junk, so I picked up a new belt just in case. I'll try swapping it out and see if it makes a difference.

 

[18w]

Michael, I appreciate the advice. My stock was about 2.75" with a 1.625" center bore. I'm still REALLY new on all this. I've been reading and watching all the videos I can. I was very careful to square up the parting tool to the end of the stock. Sounds like a little more aggressive feed and speed may be the trick.

And don't spare the lubricant! WD 40 works well on aluminum as do other products. I like Relton A-9 for parting aluminum and use WD for milling.

Darrell

 

[coolidge]

I just happen to have a new belt. The reviews I'd read said the stock belt was pretty much junk, so I picked up a new belt just in case. I'll try swapping it out and see if it makes a difference.

Have you tried a link belt? You can buy link belts at Harbor Freight, note they are made in Europe not China. I measured vibration on my G4003G with a test indicator and there was a considerable reduction in vibration with the link belt vs BOTH the China factory belt AND a Made in USA NAPA variable cog belt.

 

[Doubleeboy]

Coug67, If you are new to machining you may want to limit your parting adventures in stock larger than 1.5 inches for a while, get the feel of it, try slightly different grinds on your parting tool if HSS. I say this guardedly lest some newbie takes it as recommendation to part with tool off center, but...... sometimes dropping the tool just a little, I mean a few thousandths, not a lot, can help the tool start cutting quicker and not rub, if your feed is half decent say .010 or quicker you start to cut as soon as your tool touches workpiece, with a quick feed you motor right thru . When parting I always have my hand on crossfeed lever. If it does not start cutting nicely , starts squealing, or seems to be fighting the tool, I stop feeding , back out, turn spindle off and figure out what was wrong. I frequently dismount work from lathe, take it to saw and cut off then return to lathe for finish facing cut, to avoid the drama of parting large work.

You can also part half way thru, back out , move over a few thou and go at it again, now giving your tool some side clearance for chips to easily exit the cut.


michael

 

[coolidge]

You can also just hack it off on the band saw then face the cut edge, most times I have to face a part off anyway.