Camlock chucks

[AdeV]

How many pins does the D1-5 have?

You do not have to use all six pins. Three out of six would suffice.

Except that, as I'm making the spindle nose, I'd have to have 6 holes (even if some of the chucks I end up with only have 3, some may only be available with 6).

I need some more tooling & in particular some of those rather excellent "ultra sharp" inserts that Chronos/Glanze do.

Glanze inserts are not the best quality (toolholders themselves are good). The ones cutwel sell are branded and much better.

I'll bear that in mind, thanks. So far, I still have plenty of spare inserts (I bought a pack of 10 "ali cutting" inserts, and IIRC have a pack of 10 of the standard type too, of which I have many left. So far, I'm still on my original sharp insert. It's the screws I seem to have mislaid...

Have you considered finding a lathe with the appropriate spindle nose that someone is breaking and buying the spindle off them? All the work is done for you. I wanted to make a D1-3 adaptor for my rotary table and that's the route I went - buy a complete spindle and chop off the bit you don't need.

Before you settle on a final design, have a look at the chucks. Like with mill tooling, 40 taper is more common than 30 taper and thus is cheaper. I do not know how the prices of D1-4, D1-5 and D1-6 compare.

That would be fine for a rotary table, I should think, but not for the lathe spindle. I'd not be confident of getting it perfectly concentric with the spindle, and I'm already borderline on how far I want this thing to stick out in use.

As for the size, the D1-5 seems to give me the best range to suit my lathe. It's a decent size (6 1/2" centre height) and being old it only turns slowly (less than 700rpm flat out), so it suits the bigger chucks. I reckon 8-10" is the sweet spot, and the D1-5 copes with those no bother.

[AdeV]

If you already have a flange, what advantage are you lookig for with Camlock? Not fiddling with mount screws save a little time, but given a flange, you already have the FWD/REV safety aspect covered. If your flange is round and flat, then tight fitting chuck backplates should already remount with high reapeatablity.

a) They're a pain in the arse to change.
b) Being non-standard, I would have to machine a backplate for any chuck I bought. OK, woo, it's machining.... but easier to just buy a new fitting and have it fit straight on. In seconds.
c) Repeatability is OK until the chuck (or worse, the spindle) wears. This is a 1950s lathe. It's bound to have worn... and I can't do anything with the spindle without buggering up all my chucks. (even worse than they're already buggered, that is)

The Camlock standard has such tight tolerances as it is designed for the chucks to contact both on the taper and similtaneously on the flange.

Ideally, the camlock spindle adapter should be hardened, and then ground. The clearance at the back of the camlock taper is to provide the run out space for the grinder wheel to run out into. This is why you can't measure this dimension directly. Even if you use a sharp tool without a nose radius, and dont have the undercuts, you are not likely to get repeatable measurements on the back end of that taper to within 8 microns.

I wouldn't need to measure the taper, that's what I'm saying. I'd measure the OD of the cylinder that the taper is then cut into. I don't have suitable heat treatment/grinding facilities, so I'd have to leave it soft.

Whether an unhardened, unground approximation of the camlock spindle will give significant benefit over the standard nose flange is debatable.

Well, I guess we'll find out one day (assuming I ever get a round tuit!)

[Pete.]

Ideally, the camlock spindle adapter should be hardened, and then ground. The clearance at the back of the camlock taper is to provide the run out space for the grinder wheel to run out into. This is why you can't measure this dimension directly. Even if you use a sharp tool without a nose radius, and dont have the undercuts, you are not likely to get repeatable measurements on the back end of that taper to within 8 microns.

Whether an unhardened, unground approximation of the camlock spindle will give significant benefit over the standard nose flange is debatable.
Mark

Having had three D1-3 camlock lathes I can say yes because none of them were hardened particularly hard and one was not at all.

Aside from that, even though the spec might specify a tolerance to 8 microns you don't need to meet that spec to make a very good chuck mount. I would also say it's not as difficult to attain face and taper contact as you might think. The taper is similar to Morse taper angles and if you set a tapered shank into a Morse taper socket until it lightly 'grips' then seat it firmly with a drift you get visible movement. This movement is the range you have between contact and full self-holding friction ther ofe the chuck radially.

[RotarySMP]

I guess this is one of those cases where there is a wide space between industrial manufactured and hardened to last 2 shifts a day for 20 years, or home shop, where we moght only use it on average 1 hour/week.

I realise my posts sounded discouraging. Sorry for that. I think it is a cool idea. I took a hard look at doing the same for my Boley 4LV, but the D1-3 just doesn't leave enough space for the cam pins once you put the spindle thread through it, and D1-4 would be too big.

Please post lot of photos.
Mark

[mattinker]

I realise that you've decided to have "quick change chucks", but, as somebody who owns the same type of lathe, I really don't see the point as three nuts isn't that big a deal! When I adapted my four jaw, which came with the lathe, but had never been fitted, I made a wooden support, that puts it at the right height to line up the chuck to the spindle as well as protecting the ways! Your probably right handed, which is a disadvantage when putting on the three nuts that hold the chuck on, but even so, it really isn't a big deal! How often do you change chucks anyway! Making two backing plates for new chucks is way simpler than making a camlock nose! You say you haven't used your bed gap yet. mine has been used quite a lot, it's much more of a pain than changing chucks!

I would consider a new four-jaw for precise work and regrind in situe the three jaw. The three jaw is only really for things that are not going to be taken out and put back, run out isn't really a problem!

All the best, Matthew

[AdeV]

I guess this is one of those cases where there is a wide space between industrial manufactured and hardened to last 2 shifts a day for 20 years, or home shop, where we moght only use it on average 1 hour/week.

...plus, how often will I be changing chucks? Not _that_ often, certainly not compared to an industrial setting.

I realise my posts sounded discouraging. Sorry for that.

No problem. I am infamous for not taking advice  In fact, the more they say it can't be done, the more I want to prove them wrong  Doesn't always work... 

I think it is a cool idea. I took a hard look at doing the same for my Boley 4LV, but the D1-3 just doesn't leave enough space for the cam pins once you put the spindle thread through it, and D1-4 would be too big.

Please post lot of photos.

Will do  Don't hold your breath though, it'll be a while before I get a piece of metal big enough to do the job!

I realise that you've decided to have "quick change chucks", but, as somebody who owns the same type of lathe, I really don't see the point as three nuts isn't that big a deal!

I get what you're saying, but it's still a pain in the arse. Dunno about your chuck, but the studs on the back of mine are all so long I can't put the chuck in place & then bolt it up; I have to hang it off the studs, put the nuts on & do them up a bit, move the chuck on a bit more... takes about 3 goes to get the nuts completely on. Same to take them off. So, in general, I've just left the 3-jaw on there all the time & worked around its shortcomings as best I can.

However... having made that collet chuck, I can see me using that _a lot_. Or, if I make a Camlock "spindle nose", maybe I'll buy a proper collet chuck... complete with collet closer and all the shenanigans. Since I have to take the 3-jaw off to use the collet chuck as is, that's definitely a factor. And maybe if I can change chucks quickly, I'll be tempted to use the 4-jaw more often.

Finally - as I said at the top of this thread, all (and I mean ALL) of my chucks are old and knackered. So at some point, it's time for some shiny new ones.... which, hopefully, are a bit more parallel than the ones I've got now!

[mattinker]

...plus, how often will I be changing chucks? Not _that_ often, certainly not compared to an industrial setting.

No problem. I am infamous for not taking advice  In fact, the more they say it can't be done, the more I want to prove them wrong  Doesn't always work... 

I get what you're saying, but it's still a pain in the arse. Dunno about your chuck, but the studs on the back of mine are all so long I can't put the chuck in place & then bolt it up; I have to hang it off the studs, put the nuts on & do them up a bit, move the chuck on a bit more... takes about 3 goes to get the nuts completely on. Same to take them off. So, in general, I've just left the 3-jaw on there all the time & worked around its shortcomings as best I can.

However... having made that collet chuck, I can see me using that _a lot_. Or, if I make a Camlock "spindle nose", maybe I'll buy a proper collet chuck... complete with collet closer and all the shenanigans. Since I have to take the 3-jaw off to use the collet chuck as is, that's definitely a factor. And maybe if I can change chucks quickly, I'll be tempted to use the 4-jaw more often.

Finally - as I said at the top of this thread, all (and I mean ALL) of my chucks are old and knackered. So at some point, it's time for some shiny new ones.... which, hopefully, are a bit more parallel than the ones I've got now!

You will have to buy a new chuck, if you only buy one, make it a nice four jaw to start with! The three jaw that I have has 1/2"Whitworth (21mm) studs, the nuts are less than half the gap between the flange and the head stock, cut them down so that you can fit it without frustration! the wooden block to support the chuck means that your not holding it up in the air! between the wooden block and the shorte studs, you will find it is as easy to change as a cam lock!

[mattinker]

...plus, how often will I be changing chucks? Not _that_ often, certainly not compared to an industrial setting.

No problem. I am infamous for not taking advice  In fact, the more they say it can't be done, the more I want to prove them wrong  Doesn't always work... 

I get what you're saying, but it's still a pain in the arse. Dunno about your chuck, but the studs on the back of mine are all so long I can't put the chuck in place & then bolt it up; I have to hang it off the studs, put the nuts on & do them up a bit, move the chuck on a bit more... takes about 3 goes to get the nuts completely on. Same to take them off. So, in general, I've just left the 3-jaw on there all the time & worked around its shortcomings as best I can.

However... having made that collet chuck, I can see me using that _a lot_. Or, if I make a Camlock "spindle nose", maybe I'll buy a proper collet chuck... complete with collet closer and all the shenanigans. Since I have to take the 3-jaw off to use the collet chuck as is, that's definitely a factor. And maybe if I can change chucks quickly, I'll be tempted to use the 4-jaw more often.

Finally - as I said at the top of this thread, all (and I mean ALL) of my chucks are old and knackered. So at some point, it's time for some shiny new ones.... which, hopefully, are a bit more parallel than the ones I've got now!

You will have to buy a new chuck, if you only buy one, make it a nice four jaw to start with! The three jaw that I have has 1/2"Whitworth (21mm spanner) studs, the nuts are less than half the gap between the flange and the head stock, cut them down so that you can fit it without frustration! the wooden block to support the chuck means that your not holding it up in the air! between the wooden block and the shorter studs, you will find it is as easy to change as a cam lock!