Much the best is the first – a chuck that screws on to the spindle nose. This will allow you to pass long material through the headstock, and will have less overhang than the second, which is really intended for milling machines.

The best chucks are two-part. You screw the first part on the spindle nose and turn the (initially oversize) register to a close fit in the actual chuck bit which bolts on. This makes everything concentric to the spindle.

The second type has quite a lot of overhang (less rigidity), limits the length of work you can hold, and if the chuck you buy isn't quite true you're stuck with it.  

Whichever, drawbars are easy, just use a bit of studding and turn a top-hat collar to centre it in the back of the spindle.

Edited By John Haine on 02/06/2019 15:33:51

I use a collet chuck on my lathe and, because I can adjust it's back plate by tapping it to reduce error detected with a DTI) it's possible to centre collets very accurately. On the other hand, I have to tap the backplate to centre the chuck accurately, which is time wasted!

I imagine plugging an MT2 collet adaptor straight into the spindle would give good accuracy without messing about. The disadvantage is there's no way of tuning out any error if there is any. With hindsight, I would buy a collet adapter rather than fit a chuck, because it saves the bother of turning a back-plate.

I wouldn't bother machining a proper drawbar because a length of DIY Store M10 studding plus nut and washer would do the job. Cheap as chips. But a good looking drawbar would be easy enough to make.

Dave

Old mart,

My question is why bother with a register if it doesn’t? I thought the whole reason for a register was to get a precision fit every time? Spigots are there to add mechanical strength to the fixings (to reduce risk of shearing?).

I would go with a proper registered backplate and a carefully machined spigot for the chuck. If the actual ER chuck was off centre, send it back as ‘not fit for purpose’ (unless it came from bang good, of course.)

You can't go far wrong if you order from Arc Euro Trade. They have a very good reputation and everything that I have ordered from there has been excellent quality. Not the cheapest, maybe, but you know what they say about buying cheap . . . .

John

I machined a back plated oversize for one of my chucks for this very reason. Only held with 3 M8 cap screws and never moved!

Jim

First thing is to choose a backplate to suit the lathe. Arc Euro sell two threaded for Myford spindles, 4" diameter and 5" diameter. The backplate is drilled by the customer to make an adaptor by drilling holes to match those on the collet chuck: the two are bolted together and mounted as a unit on the spindle. The customer also turns a register on the backplate to fit into the recess on the back of the collet chuck.

I'd buy the middle collet chuck (95mm) to fit the 4" backplate, though the 100mm chuck is also a reasonable match (4" is 101.6mm). You can turn the backplate down to make it match the chuck if you want.

Dave

One of the backplates I use has been adapted to take a 4" chuck which was lying around and alternatively, the ER25 collet plate. 

I also can recommend Arceurotrade, they are also very quick delivering.

Edited By old mart on 03/06/2019 10:15:45

I had the MT2 adapter. It was ok for just short things. I chopped off the MT2 part and just hold it in the 3 Jaw chuck now. Very happy with it. I can put upto 5/8 stock through the S7 spindle into the collet chuck if needed.

I also have the smaller ER11 on a parallel shank to also go into the 3 jaw chuck.I use the ER11 for stuff under 7mm diameter. The bigger parts go into the larger ER20 or ER32 holders. The collet size I use the most on the things I make is the ER11 and most used in the 3,4,5,6mm collets.

The face plate mounted collet block I did not like very much. What I did not like about it, was the bed going forward over the gap area of the Myford lathe. With the collet holders in the 3 jaw chuck, the saddle never gets to the edge of the lathe bed. The Mt2 part was turned into a stop for the 3 jaw chuck and Er32 collet adapter.

Neil

I'll add my 2pennyworh, just watched 3 you tube videos by 'Ades workshop' on his trials mounting & using ER 32 collets, bottom line is you can normally work around a less than perfect collet chuck but if the collets do not have decent concentricity you are stuffed.

BTW Cutwel do a standard collet & a super precision offering.

Tony

Go for a 2 piece ER collet chuck screwed to the spindle nose. The reason for 2 part is you can turn the register yourself (as you would with a scroll chuck backplate) to ensure concentricity. Myford do them if you cannot find anyone else.

regards Martin

Edited By Martin Kyte on 03/06/2019 14:01:40

The Myford was designed to use Myford Collets which are 2MT direct into the spindle and are retained/ tightened with a closing ring which screws onto the nose thread. This gives the absolute minimum of overhang.The lathe was designed to be capable of turning right up to the nose. The only limitation is when the lathe is equiped with a gearbox the leadscew guard can foul the gearbox when working right up to the nose when the topslide is fully retracted. With a screw on ER chuck there is a greater overhang and this does not occur. Even when working right to the spindle nose I have never had to extent the topslide excessively. Myford collects are no longer avalable new but can be found second hand. Myford collets should only be used with dead to size material, either initially pre turned to size or precision ground stock.

I hope that answers the question.

regards Martin

Edited By Martin Kyte on 03/06/2019 14:43:47