I have never been satisfied with the runout on my D1-4 setup. After removing and reinstalling any of my D1-4 chucks they never seem to locate properly. They are every so slightly cocked on the spindle. There is a gap between the back face of the chuck mount and the flat face of the spindle. The chuck seats on the taper and is allowed to cock to one side when the D1-4 pins are tightened. Because of this remounting the chuck is not repeatable. Should the flat face of the chuck back register on the flat of the spindle? Should there be a gap between the back of the chuck and this surface? The closest I have gotten to having the chuck straight is to use shims on each of the pins to hold the chuck proud of the tapered cone. This cannot be right because it bypasses the purpose of the cone. Seems like the flats should meet and the cone center in it's mating recess in the chuck mount at the same time. Using a 12" piece of ground stock, chucked in four jaw and centered close to the chuck there may be 0.005-0.008 runout 8" from chuck. Adjust here to 0.003" and the chuck end will be out by 0.006 or more. BTW, the spindle face and the tapered cone are both as true as anyone could hope for, 0.0001 so it seems like the problem has to be the interface between the chuck and spindle. I'd be interested in any comments anyone might have. TIA Gmasterman@aol.com
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D1-4 on a PM1340
- Thread starter Gerry
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Yes it should meet the flat face on the spindle & there should be no gap. Nose taper should also register but you obviously won't be able to physically see this without bluing.
Have you adjusted the cam lock pins, does the cam mark line up between the 2 arrows (between 3:00 & 6:00) for all three cam locks? If yes the backplate may not have been machined properly or someone took a face cut on it. Sounds like that's the case since you say the backplate does register on the nose.
Have you adjusted the cam lock pins, does the cam mark line up between the 2 arrows (between 3:00 & 6:00) for all three cam locks? If yes the backplate may not have been machined properly or someone took a face cut on it. Sounds like that's the case since you say the backplate does register on the nose.
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Very common problem. Darkzero hit it correctly. The chuck should seat on the spindle taper at the same time it fully seats to the spindle face. If not, adjust the chuck to get it correct. (Not the spindle! Only gently debur the taper and face if necessary)
Its possible to experience that with the occasional lathe accessory. I had that with a new, aftermarket face plate. But a decent quality adapter plate or integral chuck should match the spindle nose exactly right out of the box. As darkzero says, full contact on the taper & simultaneously flush on the vertical face. I hope you don't have a spindle issue like egged or incorrect grind angle. It would be rare & a bad thing. Its a bit of chicken & egg thing now, ideally if you have a known good D1-4 accessory to mount, that would lay the spindle issue to rest.
Here are some pics of my poor boy lapping procedure. I cured a blob of bondo on my known good taper (wax as releasing agent), that became a tool backing using ~ 600-800 wet/dry paper in between. I pre-blued it & went around the periphery so the material removal was visually equal, clean, test on nose... rinse & repeat. I was able to get a nice fit that takes a slight bonk to get it off.
Don't be tempted to use your spindle nose as a lap! If its good & the mounted accessory is bad, now you have 2 problems instead of 1.
You can put an accurate DTI on the spindle nose, rotate & see what you get. Technically this is involving your bearings but it should be very true. It might also turn up a raised burr. Its hard to scratch the nose because its hardened & we always strive to treat this surface with care, but a ding on the surface could be enough.
Here are some pics of my poor boy lapping procedure. I cured a blob of bondo on my known good taper (wax as releasing agent), that became a tool backing using ~ 600-800 wet/dry paper in between. I pre-blued it & went around the periphery so the material removal was visually equal, clean, test on nose... rinse & repeat. I was able to get a nice fit that takes a slight bonk to get it off.
Don't be tempted to use your spindle nose as a lap! If its good & the mounted accessory is bad, now you have 2 problems instead of 1.
You can put an accurate DTI on the spindle nose, rotate & see what you get. Technically this is involving your bearings but it should be very true. It might also turn up a raised burr. Its hard to scratch the nose because its hardened & we always strive to treat this surface with care, but a ding on the surface could be enough.
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Have you blue'd it yet to see if it is hitting properly?
On one of my D1-4's 3-jaws that I got with the lathe the pins were NOT mounted/positioned properly and the chuck wouldn't seat correctly.
On one of my D1-4's 3-jaws that I got with the lathe the pins were NOT mounted/positioned properly and the chuck wouldn't seat correctly.
Thanks for all the comments! Is there some spec for the D1-4 pin stick out. Should they all be the same or within some tolerance? I really do not have a good way to measure the pin cut out location.
To use blue to check for taper interference, would you remove the pins or leave them in place, install the chuck then remove to look for? The issue I have is with all my D1-4 chucks and faceplates. None of my stuff is what I would call "high end" so my issues may very well be in the quality of my equipment-just have to figure out how to make it better
To use blue to check for taper interference, would you remove the pins or leave them in place, install the chuck then remove to look for? The issue I have is with all my D1-4 chucks and faceplates. None of my stuff is what I would call "high end" so my issues may very well be in the quality of my equipment-just have to figure out how to make it better
Just went through the process of installing every D1-4 attachment and found that I do not have a single one that butts up the the back surface. Every one leaves a gap anywhere from a few thou to a bit over 10 thou. I would have thought that out of five chucks and a faceplate one would fit right. I also find that the cams in the headstock do not all turn to the same locking point but they are not far enough out to justify adjusting the pin in the chuck a full turn. Is there a way to correct this without risk of going too far? 30+ years ago I had a POC Smithy with the same issues. I ended up turning the nose on the spindle down to make the chucks fit flat but I hate the idea of trying to do this on a good machine to rectify chucks with poor tolerances. Too easy to screw up beyond repair. So, do I need to try to make a cone from aluminum to use to try to lap the chucks to fit? I have dealt with this problem for years by shimming the back of the chuck but I'd rather do things right. Thanks for any suggestion y'all offer
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I'm surprised none of your D1 accessories fit. Something is not right. I would not touch the spindle (lapping, etc), that would be absolute last resort for me.
To adjust the pins:
Can't really measure them, not length anyway as they will vary by manufacturer. Most pins will have a line on them. Adjust the pins in or out so that this line is flush with the mating surface on the backplate. Won't be able to get it perfect, just close enough as a starting point.
Then install the accessory on the spindle. Proper lock up should be between the 2 arrows. If you don't have any markings, proper lock up is between 3:00 & 6:00 with 12:00 being unlocked.
If the cam lock does not quite make it to 3:00, remove the SHCS, unscrew the cam lock pin one turn, reinstall the SHCS, try again. If the lock goes past 6:00, screw in the pin one turn & repeat.
Won't be able to get the marks all to lock at the same position cause of how the pins are adjusted (one full turn). As long as they're between the 2 arrows it's fine.
To adjust the pins:
Can't really measure them, not length anyway as they will vary by manufacturer. Most pins will have a line on them. Adjust the pins in or out so that this line is flush with the mating surface on the backplate. Won't be able to get it perfect, just close enough as a starting point.
Then install the accessory on the spindle. Proper lock up should be between the 2 arrows. If you don't have any markings, proper lock up is between 3:00 & 6:00 with 12:00 being unlocked.
If the cam lock does not quite make it to 3:00, remove the SHCS, unscrew the cam lock pin one turn, reinstall the SHCS, try again. If the lock goes past 6:00, screw in the pin one turn & repeat.
Won't be able to get the marks all to lock at the same position cause of how the pins are adjusted (one full turn). As long as they're between the 2 arrows it's fine.
To remove chucks have to be bumped to get them to unseat. Camlocks all work as they should. Installed my collet chuck with a 1" bar. Collet chuck(from Grizzly) does not seat on the flat of the spindle. Tighten the camlocks and the chuck goes off center. By adding 3 0.005" shims spaced evenly around the flat I can get the chuck to read within 0.002. Take the shims out and you can see the runout easily. Issue is the same with every chuck. On my 3 jaw, it takes nearly 0.020 shims to get it to run somewhat true. Seems like to run true the recess in the chuck back has to be shimed away from the cone on the spindle. Go too far then the cone is pointless. Have even tried tightening the camlocks in many steps hoping to pull the chuck in centered without luck. I'm not tightening up one then move to the next on to the next, trying to do things evenly. I have even clamped a 16" long piece of stock(in my 3jaw) with a center drilled in the end held in place with my live center and then tightened the camlocks but when I back off on the center the stock moves off center. Shim the back of the chuck and this works much better. Just cannot help but think the issue boils down to different manufacturers not following the same D1-4 specs for the recess that centers on the spindle cone. Never had this problem with my old Sheldon with a screw on chuck. The spindle on my PM runs true within a thou everywhere I check. Thanks again for listening to my problems and any suggestion you can offer