Chuck backplate for a Myford 254S

[Dave Sawdon 1Participant @davesawdon1]

I believe the 254S came with alternative chuck mounts: either D1-3 camlock or 3 bolts onto a flange. My lathe is the latter which, I’m told, has the same bolt PCD and centring taper as the D1-3 – is that correct? The lathe only came with a 3-jaw chuck but I need to add a faceplate and 4 jaw chuck. What have other owners done in this situation? Is there a source of suitable backplates, or do I buy a D1-3 backplate and throw-away the pins?

[DurhambuilderParticipant @durhambuilder]

Yes – use the D1-3 camlock backplate, remove the camlock pins and use studs. I made ‘special studs one end 7/16” unf ( to fit the chuck) and the other M10 to match the other 254 chucks I had.

[alan-lloydParticipant @alan-lloyd]

I’ve always bought my backplates from warco, they came with the pins and studs at a reasonable price, watch out because some dealers charge the earth for these backplates,

[Dave Sawdon 1Participant @davesawdon1]

£69 for a simple back plate seems a little OTT when the pins aren’t needed. Unless I’m missing something, it wouldn’t be difficult to make a plate with a central hole, 3 holes on a circle and a register for the chuck. The only problem being to source the raw material.

[DiogenesParticipant @diogenes]

What diameter?

M-Machine Metals sell biggish flat rounds in various grades of CI & steel..

..always found them reliable..

[JasonBModerator @jasonb]

Ideally you would want to cut the taper on the spindle side of the backplate as well which is probably the hardest part but not impossible. I suppose as it is for a 4-jaw it is a bit less critical that you get axial location. My old Emco had a similar DIN mount and I cut the taper on the backplate that I made.

You also need to be able to hold the blank, assuming you have a 125mm 3-jaw then a 160mm 4-jaw would be a good companion size so ideally you need to hold 160mm dia billet tough a smaller backplate can be used so you may be OK with outside jaws in the 3-jaw if you go for an undersize backplate.

As Said M-machine will have the bar

[Dave WoottonParticipant @davewootton]

I’ve purchased a few D1-3 backplates fairly recently and the quality does vary enormously, so if you go down the buying route I can recommend and have used the backplates supplied by Warco, Chronos and Gloster Tooling, they all seem to come in the same packaging so I would think from the same supplier (I sourced them from multiple suppliers as they don’t have them in stock all the time). The backplates from another well known supplier were a very poor fit on the register, and after having them replaced once and the replacements just as bad I returned them for a refund. I have made a T-slotted faceplate with a D1-3 backplate integral from bar stock and it is a lot of work and swarf, I did it at work during a slack time so didn’t mind, but it did take quite a lot of machining time, I cheated and bought the pins!

PS I wished I hadn’t bothered with the T slots, radial tapped holes are much less faff to use.

[MacolmParticipant @macolm]

A Camlock faceplate is a bit tricky to make if you want to achieve the intended location accuracy. With the thing mounted and tightened, the faces should make full area contact, and the taper be a tight push fit so that the axis location is exact. What you can do is machine it up so that there is very slight slack in the taper with the faces in contact, then face down on fine abrasive to get the correct taper fit.

A satisfactory fit is when on releasing the pins (or bolts), the taper holds in place, but a light thump with a fist releases it.

[Dave Sawdon 1]

On Dave Sawdon 1 Said:

£69 for a simple back plate seems a little OTT…Unless I’m missing something

main difficulty is getting nose dimensions correct:

There was an article in MEW (No 102 Nov 2004) about making it, using fitting gauge.

There is also an excellent YT video about making short taper dial indicator/gauge to help with making it

(if you have original good quality master backplate to compare):

I have produced (successfully) backplate of this type for my lathe,

which has DIN 55021 spindle (same as D1-3).

It can be done, but to be honest… considering what’s involved in getting it right,

next time I might spend £70 with Warco

[Chris KaminskiParticipant @chriskaminski64716]

Pratt Burnerd 4  jaw chuck with integral D1-3 back converted to three bolt fitting

[Dave Sawdon 1Participant @davesawdon1]

Thanks for mentioning M-Metals (what a great stock) and for the other replies.

I’d forgotten that, only having access to the one lathe, I would have to make or buy a master before being able to make the backplates. Considering the time and material cost it’s probably better to buy this time and reconsider if I can find or scrounge some material for blanks.

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