D1-4 on a PM1340

It is very unusual for every chuck to not seat on the spindle taper properly. One maybe, but not everything. Chucks are ground to a standard so if they all do not fit properly then it just has to be that the spindle taper is off. You might try checking the spindle mount to see if it fall within specs. If it does not then a call to Matt is in order.
 
Make sure there is a nice deep relief around your spindle nose.
Also the spindle nose should be 11mm tall/high.
Highly unlikely you'll see anything but worth a looksie.
 
I agree with Mike, highly unusual for all your D1-4 accessories not fitting correctly. Do some measuring to see if your spindle meets specifications. If not should probably give Matt a call. Is the lathe new (recent purchase)?

Edit: Oops, didn't notice Mike included a link already

D1-Camlock Dimensions.jpg
 
Another thought, if you completely remove the cam lock pins & place the backplate on the spindle, will it then make contact with the spindle face?

From all that you mentioned, it sounds like the spindle nose it too large/long. If that's the case I would get it replaced under warranty.
 
I have to say Matt has been EXTREMELY helpful in the past. Lathe is 10 years old and came with the wrong pitch gear in the thread dial. After trying to thread and failing many times(I am always the first to blame myself for anything that goes wrong) I contacted Matt and he had one custom made to replace the wrong on. Lathe was 6 years old at the time and he was not expected to furnish the right gear because the lathe was way out of warranty but he did. He is a fine fellow in my view, I just hate to involve him unless I have no other choice. I bought the lathe from him in 2008.
 
Yup Matt is awesome. Always willing to help, don't hesitate to contact him, he's just busy all the time which is unsurprising. He has given me parts for free that were not warranty related. Heck, he even upgraded my DRO display for free & gave me my 8" Vertex rotary table for free, wouldn't even let me pay shipping! Why, I have been wondering ever since but I am forever grateful.

So your lathe has been like this ever since you had? Even though out of warranty should still give Matt a call IF your spindle was machined out of spec. Should never have to use shims, the spindle is the most important part of the lathe, it should be accurate & repeat (unmounting/remounting chucks).
 
OK Gerry, I've seen something similar before. it is possible that there is a super simple fix: Please forgive me, but many guys don't tighten their D1-4 camlock properly and then grind down the spindle, like you were tempted to do.

Please try this procedure, and recheck the shim spacing behind the chuck to see: 1) if the gap disappears, or 2) if the thickness of the shim is less and if it is even.

Remove the chuck and reclean all surfaces with a solvent and wipes.
Put the chuck on very lightly, so the camlocks 'just catch'.
Rotate the camlocks, one at a time to the same rotation, but not hard (yet). On mine, it 1/2 way to the line and things begin to feel 'just snug' equally.
-- this, believe me is a necessary sub step, forD1-4 and D1-6 camlocks: everything should be lined up at that point.
If you wonder why, it is because if the chuck goes on cocked, it will never seat all the way down, even on perfectly fitting tapers. that's because the taper is much larger than it is long, and if it is already on diagonally, it cant seat all the way down.

You've checked everything is still parallel and straight. then tighten each -not all the way, but to about 3/4 of full tightness.
THEN and only then, tighten all the way.

I do this every time I use either camlock - and the guy who sold me my D1-4 machine reported the exact problem (of course after I paid for it).
When you do the 3 rotations like this it becomes automatic and they align perfectly every time. I was taught this 3 turn procedure nearly 40 years ago on the D1-6 lathe I just bought. The tool and die maker I got it from always did this procedure, and the chucks registered perfectly each time and the spindles show zero wear. And his chucks are always marked so the cams always meet the same studs.

Get back to me if this hasn't improved. There are a few other things to check. An offshore chuck adapter On someone else's lathe from a big name company showed the exact opposite problem (taper too loose), but in that case it requred remachining the backplate to make it fit properly.

The chances your spindle is out are miniscule. the next check is for spindle roundness in half tenths. That's far more likely than the taper being the wrong angle or too large. If the spindle is out by more than a half or 3/4 tenth , it will lead to the chucks always being on crooked.

If, however you've used the lathe for 10 years by putting your chucks on crooked, you will have worn your spindle out and made it non-round. This is an advanced fix.
 
Sorry for the grainy picture but somewhat shows the D1-4 relief groove on my Taiwan 14x40. The camlock diagram shows dimension B as 2.5005" but it doesn't show a relief groove. I remember wondering about this before, does B correspond to the theoretical diameter of the extended line intersecting the vertical surface when a groove is present? I can measure mine or take a better picture if you think its helpful. Its not exactly easy to verify the nose angle to the 7-3-30 accuracy, but there probably is a way. But you should be able to caliper the big end, small end & stickout just for a sanity check.

From everything you've described it appears like the spindle is a slightly larger diameter than your accessories. That would explain them all hanging prematurely up on the taper with open gap between the vertical faces. When this happens, the accessory can easily get cocked at an angle because its not mating along the taper. Sucking in the camlocks is just applying more force to a geometry problem (assuming the studs & lengths are all checked out). The other explanation is the accessory tapers are undersize to the spindle. But I get the impression you have tried a bunch of 'proven' ones all with same result? so this seems unlikely. So this is a new lathe where the problem cropped up?

I would do some basic Sharpy marking blueing & just gently push the best fitting accessory on by hand & see what it tells you. You can see by the post#13 chart that dimension B between D1-2,3,4 are significantly different, so hard to imagine the wrong spindle is inadvertently installed. Some of the big bore 14x40's have D1-5 but I'm pretty sure that would be a lot more mismatch evident. Yours sounds close but no cigar.
 

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Sorry to resurrect an old thread, but I think the post I am making should be here instead of starting another thread. Besides, I don't see a resolution posted here by the original author anyway.

FYI, I have the PM-1228VF-LB lathe and am having the same exact problem. I have 5 different chucks and NONE of them will contact the faceplate of the spindle. They are all seating on the back edge of the taper. I am discussing this problem with PM right now to see what they can come up with. FYI, two of the chucks came from them, so the premise that ALL of the chuck backplates have been machined out of spec is kind of hard for me to swallow.

And for the record, I did try the above mentioned method of tightening down the camlock pins slowly and alternating among them. Didn't help. If the chucks will not contact the faceplate, trying to get the chuck exactly centered on the taper is not my idea of good way to spend my time.
 
@Tired&Retired

If progressively tightening the camlock doesn't do it, then the fit has to be the problem. I wish I could be there to have a look.

The next thing I would try is to use a tenths indicator to ensure your spindle taper is concentric and is radially symmetrical.

If it is, I'd do a 'wear test' by taking the chuck that fits best, putting sharpie onto the taper, and put the chuck on, and then remove it. Check and document where the sharpie has worn off. Then index the chuck one pin, and repeat. Do this all the way around. You might be surprised by what you find.
 
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