Triumph 2000 dead center head stock drive

[lee gilesParticipant @leegiles21499]

Hi, what is the best way to fit a driven dead center to the head stock of a triumph 2000 please?

I have never turned on centers, I have only used a live tail stock center to support a job in the chuck but i have a job coming up that I will need to turn on centers.

Thanks!!

lee

[lee gilesParticipant @leegiles21499]

[Brian WoodParticipant @brianwood45127]

Hello Lee,

With a spindle bore in excess of 2 inches in diameter, I think you will have a job fitting any kind of centre.

Instead, turn a centre on the end of a piece of bar gripped in the chuck and mount the job between that and the tailstock centre.

Regards

Brian

[JasonBModerator @jasonb]

If you are lucky it will have the reducing bush so you can just pop in a standard MT dead ctr

Brian's method is as good if not better, just don't remove the homemade ctr until the job is complete, you can often use one of the chuck jaws to drive a dog.

[capnahabParticipant @capnahab]

In case your looking here is an example of a reducing bush for a DSG. Not sure what the outside taper is.

[Nigel McBurney 1Participant @nigelmcburney1]

Colchester lathes were supplied with a hardened and ground reducing bush which fitted the spindle and was bored to accept a 4 morse taper centre. You should be able to get one from one of the dealers specialising in used machine tools, try G & M tools ,or Home and Workshop machinery etc When I needed a bush for my Colchester master 2500 I got one from G & M tools but I did find that the bush from a earlier roundhead master was different to the 2500 bush.A catch plate to drive the lathe carrier can be obtained from similar sources,or the face plate can be used. A home centre can be made by obtaining a short length of 1.5 or 2 inch bar then bore out and weld a disc of steel halfway along the bar ,the disc wants to be about 6 to 8 inches in dis for a 2000. .drill a hole in the disc so that a bolt with two nuts can be fixed to the plate to drive the lathe carrier. put the bar in the chuck with the disc hard up to the jaws,so that it cannot slip in the direction of the headstock, If it does slip the work can come out from between centres. Turn a taper on the bar to make a centre (60 degrees) , this produces a very accurate centre but of course the centre has to be skimmed every time it is used.Years ago soft centre were available but none seem available now. If this is the first time you have turned between centres you will need to reduce your usual cutting feeds as the workpiece is not so well supported compared to chuck work or chuch and centre. Ensure that a disc is used for the home made centre,if a bar o metal is used instead it can cause a lot of harm if you catch your hand or clothing in it,thats why catch plates are circular.

[lee gilesParticipant @leegiles21499]

Thanks for your help everyone! I will try M&G if not I will make one as suggested.

If I go down the make myself route what hardness steel bar should i use? something like EN24T?

I am guessing a Through hardened material would be preferable so if it did wear at the point the material hardness doesnt drop off?

Really appreciate the advice thanks!

lee

[Bob Brown 1Participant @bobbrown1]

The centre in the headstock should not wear as it rotates with the work piece.

Bob

[LambtonParticipant @lambton]

Lee,

As the centre in the headstock rotates with the work piece it does not need to be hardened mild steel will be OK. In fact MS has the advantage of being capable of being easiiy trued up before use as described by Brian.

When turning between centres watch for the work warming up and expanding along its length requiring the tailstock end to be adjusted accordingly to prevent any distortion, particularly if the work piece is of small diameter.

[Steve PaveyParticipant @stevepavey65865]

I can't really add anything to Nigel's post above, except that it might be worth checking that the spindle bore is in fact MT4 – my Harrison lathe (both Colchester and Harrison were part of the 600 Group) has a spindle bore with a 4 ½ MT bore – some of the Clausing (made by Colchester I believe, and badged for the US market) lathes were also 4 ½ MT as well

If you need to turn between centres only occasionally, you could just chuck a bit of 1" bar in the 3 jaw, turn a 60 degree point on the end and then drive the work with a dog riding against one of the chuck jaws.

edit – I see Brian has already suggested doing this.

Edited By Steve Pavey on 10/08/2015 17:10:22

[AjohnwParticipant @ajohnw51620]

I've been looking at D1 3 Boxford spindle fittings recently. From this it seems there is some standard relating to the taper in the spindle so that a bush can be fitted to take a standard morse fitting. It could be that D1 D2 etc all have their own standard sized bushes. Boxfords spindles for instance take a No 4 1/2 ASABS.10 that has a 3 morse socket in it.

John

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[KWILParticipant @kwil]

No 4 Morse Taper centres was the standard supplied with this lathe.

Handbook here–

http://www.chainganger.co.uk/T2000/Colchester%20Triumph%202000%20footbrake%20manual.pdf

[Steve PaveyParticipant @stevepavey65865]

To correct my post above, it is now clear that the external taper of the reducing bush is obviously not MT4 ½.

Looking at the hendbook it is possible that the reducing bush will have an MT6 external taper (assuming that Colchester actually used Morse tapers and not one of the many other standards). The MT4 taper referred to in the handbook refers to the internal taper of the bush. This is my guesswork, based on the spindle bore of 2.125" and the size of an MT6 which is 2.494 to 2.116".

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