Threading on a PM1127 lathe - turning instead of threading

Pcmaker said:
This is what's on the lathe itself. What's the top box for? If the middle is metric, the bottom box is inches, what's the top?

gAw2KJH.jpg
Click to expand...

Ok, that's better, I'd follow the chart on your lathe instead of the manual. As I said above I don't understand why there are 2 gear combos with the same lever position for 1.25mm pitch in the manual.

In my post above, follow the gear combo in the second pic as that's what matches the chart on your lathe.

The top section is for feed rate in inches (used for roughing & finishing passes). When you hear IPR (inch per revolution of the spindle), that's what that is. The first 3 lines are feed rates for the carriage. The next 3 lines are feed rates for the cross slide.



So starting from the top for 1.25mm...

60T on the inside/right side, spacer on the outside/left side.
63T on the inside, 50T on the outside. 63T meshes with the 60T.
Spacer on the inside, 80T on the outside. 80T meshes with the 50T.
Lever on position A.
 
These charts seem messed up to me. Look in post 24 where you can see all 6 boxes. Look at the bottow 2 boxes left and right. The QC gear positions change left and right for B & C with the different gears combos. Then look at the A position. It stays the same left to right yet the same gear combinations that change B & C are NOT changing A. That seems impossible.
 
The manual has, I think, a set for metric leadscrew. Use the inch side, PM only sells inch leadscrew models. It matches the one on the lathe.

The top chart is for feed rates. It shows the rates for longitudinal and cross feed.

The gear setup for threading looks weird compared to how it came.

For metric threads, remember that you can't disengage the half nuts once you start or use the thread dial. (there are a few ways, but for just starting out, it's just easier).

For the sleeves, yeah, mine were a bit tight. I took a file to them. You only want to take off just under a thou. I believe it was an "X" drill bit I ran through it as well. Mostly to clean up burs from filing. :)

If you do that, don't take much off. You want them snug, slop in the gears would be bad.
 
ttabbal has it right.....use the chart on the lathe......its riveted to the lathe for a reason...can't misplace it or get on the wrong page of the manual.
Top chart..cross feed and longitudinal feed in inches.
 
I think I figured out the gears, but now the issue is the washers. Trying to figure out how to how to keep the right side of the gears from grinding on the banjo and to keep the gears from "wobbling." That one is probably a washer issue, too.
 
If the gears are wobbling or scraping, they are installed incorrectly.

There are 2 washers for each gear stack. Large ID goes first on the axle. The small ID goes on last. Once the axle is tightened, there should be no play in the gear stack, other than being able to rotate.
 
Pcmaker said:
This is what's on the lathe itself. What's the top box for? If the middle is metric, the bottom box is inches, what's the top?

gAw2KJH.jpg
Click to expand...
I believe the box indicates feed rates for the feed screw instead of the lead screw in thousandths.
 
I would try to put a spacer and a 60T gear on the Z1/Z2 spindle with the 60T gear meshing with the 40T gear. The Z3/Z4 spindle gets a 63/50T gear with the 63T gear meshing with the 60T gear on the Z1/Z2 spindle. The L spindle gets a spacer and an 80T gear with the 80T gear meshing with the 50T gear on the Z3/Z4 spindle. Also, You would need to be in the A position.
 
the top box is feed in inches/revolution. Look at the little drawing on the left. The first one show a lathe tool cutting longitudinally and refers to the first three rows. The second drawing is a lathe tool facing a shaft (crossfeed) and refers to the next three rows. You use the feed lever for these and the power goes thru the gears in the apron to slow it down way more than the thread settings. Lottsa good stuff in the apron!DSC_0708.JPGDSC_0713.JPG
 
We're repeating ourselves. I said, we're repeating ourselves. ;)

Tom
 
You must log in or register to reply here.
Back
Top