10x22 Lathe spindle

[rogee07]

Yes it is a precision Matthews 1022 lathe.
I have had a PM 1022 lathe for the last three years a very nice machine, but a bit on the light side, and I find that changing the gear train to cut threads a real P.I.T.A. I also ordered an extra backing plate, with the intention of mounting an er collet chuck, but never got around to doing the job. They don't have one in stock at this time, and I would not hold my breath waiting for one to come in. as I have been waiting for two years for some extra change gears that I ordered. It would not be much of a job to mount a er collet chuck in your 4 jaw. chuck.

[Doozer]

This seems like a really cumbersome way to mount a lathe chuck on a spindle.

[old mart]

Tensecondsdown, where are you located? I thought Europe was a good guess because of the CE mark on the lathe.

[OaklandGB]

Doozer,

I am skeptical of this mount too, but it seems to work OK in my limited experience with it. That dark knurled ring in the pic is a captured, slotted ring like a giant washer with 3 slotted holes it that allows the chuck's mounting studs -with the bolts on them- through the "hole" part of slots. After they are in place you gotta rotate that ring so the bolts engage the "slots", then tighten the bolts with a flat open end wrench.

I believe that the chuck registers on the face of the spindle so the ring has to only provide a landing spot for the bolts to pull it up tight to the face of the spindle. I guess I would prefer a bolt through holes type mount even if it means tight quarters behind the chuck to get bolts started. Oh well, it is what came with the machine.

Like I said, it seems to work OK,. Haven't noticed any deflection in this knurled ring nor a lot of on-line complaints on this style, but then, it is a light duty hobby lathe.

[OaklandGB]

While strayed a bit off the topic, this is the "shutter ring" type mount looks. The spindle flange holes are large enough to admit the nuts on the chuck's mounting studs. Then the shutter ring is rotated to expose the slots for the nuts to tighten down on. I wonder if I could substitute 3 thick, larger washers in place of that shutter ring? I don't lose much sleep over it, but occasionally toss and turn about it. Couple of screen shots from the manual to show how this mount is supposed to work in case anyone is curious.

[old mart]

Now I see how the shutter ring works. It is to make the changing of the chuck much easier.
Oakland, I assume that you would like to increase the stiffness of the mount with thick washers at the expense of loosing the ease of changing the chuck. The only way that the shutter ring could be removed without taking the spindle out would be to cut it up. The thick washers could be double diameter to fit in the large holes and have a thinner flange next to the nut.

I wish my 7 X 12 had the shutter ring style mount, arthritic fingers and little nuts in a confined space make for much cursing. The only way I could improve things was to turn off the threads on the end 4mm of the studs so the nuts had something to sit on before starting screwing on.

[OaklandGB]

OldMart,
I think we are in the same boat. Retired now, and the joints are tougher and tougher to loosen up if at all. Still have to wrangle the nuts down in that limited space while holding the shutter ring in place, it is nice not to drop the nuts while trying to start them. Being a total amateur, but highly interested, I struggled a year and a half before buying a hobby lathe from PM. Power cross feed, variable speed, the quick change tool post, and some halfway decent reviews brought me to look at the PM line, and I bought it. I was clueless about chuck mounting systems at the time. But, I'm still happy with it. It is the same lathe Blondihacks uses, so I follow her channel regularly. Light cuts with HSS tooling is the order of the day but it is quite capable within its working envelope.

I would probably make the same choice again, shutter plate mount and all. It has been a couple of years but has worked out well on the few times I switched from 3 jaw to 4 jaw and back again. So far, no distortion, or slippage of that shutter plate, but I don't abuse it either. I think is is hardened, but trusting a couple of shoulders to set the nuts on, just gives me some minor angst.

Maybe this discussion, while it has wandered off OP's original question, will help some future hobby machinist take the plunge. Most enjoying, fascinating, boundless, and at times, frustrating, hobby imaginable.

[old mart]

You could mark the shutter plate and the spindle flange when the plate is fully in place to be sure it hasn't moved when the nuts are tightened. As you mentioned, the lathe is not expected to be highly stressed and the design, while not perfect is never likely to give trouble.

TSD, your reason for wanting the plate is the best solution for long bar stock, and should you also have, or be thinking about a mill, then the collets you have can have a dual purpose in an er40 adaptor for it. Also, with a mill, the entire plate can be clamped on the mill bed for additional use, as recently shown on the British Model Engineer forum.