Carriage Interference PM 1127-VF-LB

[Logan Novice]

The carriage on my PM1127-VF-LB falls short of its full length of travel because the carriage strikes the face of the collar on the feed screw shaft. {part no. 25 (collar) in the gear assembly section owner's manual} as the carriage approaches the headstock. The collar's diameter is approx. 1.373" +/- (35mm) and I can't be sure if the interference is due to misalignment of the carriage apron or if the collar is simply too large. My plan is to turn down a replacement collar to a diameter that will eliminate the interference. I'm waiting for a response to my email to PM seeking their advice before I move forward with this idea. Wondering if any other PM112 owners have had to address this issue?​

 

[ttabbal]

I can get the tool as far left as I would ever want to. Any further and I would crash into the chuck jaws or similar. Even the shorter collet chuck works fine. I suspect that mine does hit the same spot your are asking about, but I can't say for sure till I'm at the machine.

Perhaps your compound needs to be moved around a bit?

 

[Logan Novice]

I can get the tool as far left as I would ever want to. Any further and I would crash into the chuck jaws or similar. Even the shorter collet chuck works fine. I suspect that mine does hit the same spot your are asking about, but I can't say for sure till I'm at the machine.

Perhaps your compound needs to be moved around a bit?

Thanks for the input. I'd really like to know if the left side of your carriage contacts that collar. At this moment, with a MT center in the tail stock and another in the headstock spindle (even with using a MT5 to MT3 sleeve adapter for the spindle center, which adds a bit of length to the center) I cannot get the tail stock close enough to the headstock for the points of the centers to touch.

 

[ttabbal]

Mine actually hits the collapsed leadscrew cover. It looks like it would hit the collar as well.

That said, just make a tailstock alignment bar. It's also easier to use and more accurate. That's the only reason I can think of for wanting to do that.

 

[Logan Novice]

Mine actually hits the collapsed leadscrew cover. It looks like it would hit the collar as well.

That said, just make a tailstock alignment bar. It's also easier to use and more accurate. That's the only reason I can think of for wanting to do that.

Thanks very much. You've convinced me that the design wasn't intended to allow the carriage to travel any further to the left than it does so I will do my best to abandon my OCD behaviors and just accept things the way they are. This whole episode was born of an alignment check technique I learned many many years ago (and used often with my vintage Logan lathe) where you can use a 6 inch steel rule held between the two opposing points (one headstock, other in tailstock) and if it holds a 90 degree angle from the horizontal plane of the lathe bed it's plenty good enough. Without having both centers touching I can't do that.