Another obligatory New PM-833TV and PM-1340GT Ordered!

Mounted up what I thought was a 2” bar of aluminum, faced, flipped, then tapped in to within 1 thou runout in the 3 jaw. I’m guessing it’s about 12” stuck out. Took very light cuts. Whole bar cleaned up. My micrometer wouldn’t fit as it was a 2.25” bar so I measured at the jaw, then about 8” from the jaw. No detectable taper with digital calipers (igaging)

Great news, even though my facing cuts are about .001” convex at 3”.

I’ll take this win.
 
I still believe your headstock is not aligned if you get any dishing on a cross slide cut, may take some additional work. maybe try to mount up an 8" chuck and check the distance at the front and back with a dial indicator to check if it is square to the cross slide.
 
mksj said:
I still believe your headstock is not aligned if you get any dishing on a cross slide cut, may take some additional work. maybe try to mount up an 8" chuck and check the distance at the front and back with a dial indicator to check if it is square to the cross slide.
Click to expand...

I tried to align the spindle to the cross slide. If I do that, my x is off. I honestly believe my apron was not made exactly perpendicular to the ways and cross slide
 
Christianstark said:
I tried to align the spindle to the cross slide. If I do that, my x is off. I honestly believe my apron was not made exactly perpendicular to the ways and cross slide
Click to expand...
If you are interested in digging deeper into this, DM me. Most lathes are set up for the cross slide to move towards the chuck when advanced - but at a rate of 0.0005" over 6" or more.
 
On a silly side note, this weekend I decided to get more organized with my tools and as part of that I was making sure all related part of tools were in places that make more sense (storage wise) when I came to the sudden (and erroneous) realization that I had one set of outside jaws that fit my 8" 3-jaw chuck on my dividing head but did not have the jaws for my 6" 3-jaw or 8" 4-jaw chuck. In a panic thinking they were stored in some place that made sense to me 2 year ago, but baffeled me today I set out at doing a deep cleaning of everything in my shop.
Well a few days later, and realizing that I really needed to do this sooner it finally dawned on me that I did not get those jaws for my 2 lathe chucks because 1) the 3-jaw chuck has bolt on reversable jaws rather than jaws with a scroll machined in the Jaw. 2) the 4-Jaw chuck (which I have not needed yet for what I do in the lathe) the Jaws are reversable because they use big acme threads and not the spiral scroll of the 3 jaw.
I feel silly, but hey at least it forces me to organize my tools better.
 
Quick question, when you put the test bar in and slowly rotate the spindle does the reading stay at "0", if so then I agree that the cross slide is not running true. I would contact PM/QMT as to suggestions and replacement if needed. The variance of 0.002" across the spindle with the head alignment bar running true is not acceptable.
 
mksj said:
Quick question, when you put the test bar in and slowly rotate the spindle does the reading stay at "0", if so then I agree that the cross slide is not running true. I would contact PM/QMT as to suggestions and replacement if needed. The variance of 0.002" across the spindle with the head alignment bar running true is not acceptable.
Click to expand...

Yes. I can rotate the test bar with minimal fluctuations
 
mksj said:
Quick question, when you put the test bar in and slowly rotate the spindle does the reading stay at "0", if so then I agree that the cross slide is not running true. I would contact PM/QMT as to suggestions and replacement if needed. The variance of 0.002" across the spindle with the head alignment bar running true is not acceptable.
Click to expand...
 
Put your indicator on the face of the spindle nose and also on the outer diameter of the nose (as shown in this photo) and run the machine slowly again to see if either of those surfaces show runout. A camlock chuck should register to those surfaces, not the surface that the indicator is currently against in this photo.

screenshot_127.jpg
 
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