Myford 254 S

Hullo all, I have contacted Myford to get a set of inner and outer jaws for the chuck, or a complete new chuck, but nothing is available, they don’t carry these parts anymore. I would imagine other owners of the 254 S might have had the same problem. Can a backplate be fitted to take an aftermarket chuck ? Any help would be appreciated, thanks, John Parry.

I would try the manufacturer of the chuck

If I remember correctly the 254s uses standard D1-3 chucks.

Ian

If Myford won't help you could talk to Rotagrip or maybe a BS0 dividing head may fit.

As Ian says the lathe uses the D1-3 Chucks/Backplates the non standard spindle still has the D1-3 nose taper all you need is to remove the D1-3 pins from the chuck and replace with suitable threaded studs and nuts. Same with a backplate..

Edited By MichaelR on 11/06/2021 18:18:31

I bought a D1-3 chuck from Rotagrip replaced the pins as described above for my 254 even managed to get soft jaws to go with it. Same chuck as the one I already had it does not have a name just some numbers.

I have a 254S, and yes it has a D1-3 chuck mounting. It is truly a great way to fit and change chucks. I am currently looking for a 200mm, D1-3, Independent 4 Jaw Chuck. I can get a 150mm one but the 200mm ones tend to have a D1-4 mounting which is not compatible with a D1-3.. Burnerd and Bison D1-3's are available for too many hundred pounds, for what is going to be a single project/batch of parts. I continue my search and there was one on ebay last week, but it had been wrongly described and was again a D1-4. So as I do have a 200mm D1-3 back plate from Chronos, I intend to buy a 200mm front fix chuck. Turn a register on the faceplate and mount a Chinese 200mm chuck on it. Problem will be solved.........unless somebody has a 200mm D1-3 Independent 4 Jaw Chuck they are willing to sell to me.

Hi John

There were two types of chuck mounting on the 254's the D1-3 Camlock or a taper with three studs as used on many chinese lathes. The camlock has three square keyholes that operate cams to pull the chuck in and hold it, the other a flange with three holes,you will need to identify which type yours is. A bit of googling or posting a picture of your spindle nose would help.

D1-3 backplates and chucks are easily available, I have purchased from both Warco and Gloster tooling with complete satisfaction, not tried Chronos. But I had to send the backplates from another well known supplier back as the fit was appallling. I bought a 125mm 4 jaw s/c from ARC and am very pleased with it.

I seem to remember reading that the D1-3 backplates can be easily modified to fit the non camlock spindle by replacing the existing camlock pins by studs, but my memory often fails me!. I'm sure someone on the forum will know more about that type of mounting. If you PM me I can try to scan the page from the manual showing chuck fitting.

Dave

Just re-read the trail above after morning caffeine injection and had missed that the D1-3 backplate conversion has been covered already, so it's not only the memory thats failing then! But I did have a very late night yesterday!!

Edited By Dave Wootton on 12/06/2021 07:27:39

Edited By Dave Wootton on 12/06/2021 07:30:24

Are you sure it is a non-standard spindle?

If the D1-3 taper fits, there is a possibility it is an A2-3 taper.

See https://www.smalltools.com/lathe-spindle-nose-identification-chart/

The A-series tapers were more popular in Europe. From those I have seen, the stud has a reasonably precise plain diameter that goes through the holes in the spindle before being threaded at a smaller diameter, then a washer and a nut.

D1-x camlock chucks may be fitted to many Chinese lathes but they were devised in the 1930's and fitted to many high quality machines long before the Chinese adpoted their use. It's a very secure and popular fitment.

I'm aware of that which is why I put the word or in the sentence to differentiate between D1-3 and the 3 stud method.

Dave

Good morning, and thanks to all for your input. I think to contact Rotagrip will be the answer. I have had th chuck off, a 17 mm spanner was needed for 3 10 X 1.5 flanged nuts holding the chuck on. A long piece of bar tightened in the chuck, soon gave enough leverage to release from the taper. Only a short tapes, quite shallow. To Dave Wootton, find me on Facebook, for any message. I am on several Bultaco motorcycle sites (there is no known cure ) ! Again, many thanks for the advice given. John Parry

Just to clear this up, Myford supplied the 254s with either the cam lock spindle or non camlock spindle depending on how much you wanted to pay. The taper on both spindles for fitting the Chuck, is a D1-3 regardless of which one was supplied, the D1-3 chucks can be fitted to either spindle by removing the pins and fitting studs as mentioned earlier.

Any D1-3 Chuck will fit.

Edited By Ian Hewson on 12/06/2021 09:45:27

Think you have a "B.S.4442-A3" spindle according to Tony's site.

The far eastern lathes upto the 280/290 size do use 3 studs but seldom have a taper, the spigot is a close fitting parallel one.

That’s correct, designed to take D1-3 chucks.

Thanks Jason B, yes, mine is the standard 3 stud, non camlock version. Looking again at the general information booklet that I have, the spindle is to BS 4442, so that is what I need to quote when ordering. To mention, the Bultaco motors I work on have a bronze bush in the kickstart assembly. This gear rotates all the time the motor is running. Over the years, with possibly not much in the way of oil changes, or using a wrong oil, I have come across some really worn ones. Normally, I turn a new bush, press in, then ream to final fit. The last one I did, when fitted, wobbled quite a lot. Strange, I always machine the outer diameter first, then the inner diameter, allowing a few thou to use an adjustable reamer to get the final diameter. I assume it is a worn chuck and jaws causing this.

See https://shop.bsigroup.com/ProductDetail?pid=000000000010086127 where it states the standard is withdrawn.

You might have more luck if you quote a more modern and internationally-recognised standard.

See: http://www.lathes.co.uk/spindlenose/spindlenoses.pdf (A2 spindle nose).

The standard may be withdrawn, but he will not have any trouble sourcing a D1-3 Chuck on the net in the UK, we’re as he would asking for an A2. Just try looking at any of our usual suppliers, including RDG/Myford.

As others have suggested above, the 254 series lathes were fitted with a BS 4222 spindle nose. That defines the taper (1:4 on the diameter) and the PCD and size of the bolt holes. They are the same whether studs or cam-lock pins are fitted.

D1-3 back-plates fit the Myford spindle, but you will need to make up some studs with, as you have identified, an M10 x 1.5 thread. (The holes are 10.5 mm diameter.)

Then it gets more interesting. Don't assume that just because the thread on the spindle end of the studs is metric that the other end is. The cam-lock pins for a Pratt-Burnerd back-plate are threaded 7/16" x 20 UNF and not M11 x 1.25.

ETA: 7/16" x 20 = 11.11 x 1.27 mm. How do you think that I found that out? 

Edited By Chris Pearson 1 on 12/06/2021 18:20:05