Integral lathe chuck V Backplate

[fizzy]

I have been offered a nice Burnerd collet chuck for my lathe. Price is ok ish. Only thing is it isn't a dedicated L1 fitting but has an L1 backplate fitted.
Is this a problem? Very old so I doubt it is a Chinese backplate!

 

[Hopefuldave]

It'll mean about an inch extra stick-out from the headstock, not a problem unless you're running out of room on long work - which you robably won't be doing in collets?

Dave H. (the other one)

 

[fizzy]

It'll mean about an inch extra stick-out from the headstock, not a problem unless you're running out of room on long work - which you robably won't be doing in collets?

Dave H. (the other one)

No problem with room - 48" between centres!

Just worried about less accuracy.

 

[Agroshield]

In principle, a backplate-mounted one can be more accurate than an integral one.

The integral one was originally machined on one machine and will now be mounted on another machine, which at some infinitesimal level will be different.

A backplate mounted one allows you to dial in the the collet taper to give zero runout on your spindle.

Check which size collet it uses and that all the collets are there with it and in good condition. EC is the common size; EB is smaller and rarer; EE is bigger and rarer. Collets second hand are £60 upwards each. Look at Rotagrip's site when seated for new prices. Also make sure it has the key as these are difficult to find when missing and a standard Jacobs key does not fit properly.

 

[Pete.]

Hardinge Sjogren collet chucks come in backplate variant and you're not getting much better that that in terms on accuracy.

https://www.shophardinge.com/assets/docs/SjogrenPtsLst.pdf