4 jaw help

[mike os]

Bought an er collet chuck with a straight shank thinking I can center it once then use it for easy centering on smaller sections


It has a 100mm mm long shank and it is only clamping at the back of the jaws meaning I have movement. ...... pain in the proverbials. ... only 0.2mm but that's a lot lol

Is this normal for a 4 jaw chuck?.... would cutting down the shaft to say 40mm work or will it simply grip further forward and still move?


Suggestions please,

 

[ukracer]

Bought an er collet chuck with a straight shank thinking I can center it once then use it for easy centering on smaller sections


It has a 100mm mm long shank and it is only clamping at the back of the jaws meaning I have movement. ...... pain in the proverbials. ... only 0.2mm but that's a lot lol

Is this normal for a 4 jaw chuck?.... would cutting down the shaft to say 40mm work or will it simply grip further forward and still move?


Suggestions please,

Do you mean you intend to center the collet chuck in the 4 jaw you already have but did not know it was bellmouthed?

 

[mike os]

Do you mean you intend to center the collet chuck in the 4 jaw you already have but did not know it was bellmouthed?

Yes

 

[grim_d]

Sell it on and get a collet chuck for your spindle instead.

https://www.arceurotrade.co.uk/Catalogue/Collets/ER-Lathe-Collet-Chucks

 

[mike os]

Found that today grim..... couldn't find mt5 when I was looking..... also need a locking ring retainer for the chuck mount....... was hoping to avoid that as I can't find one for a Colchester at the mo

I might have to adapt the 3 jaw backplate as it's ******** anyway but it's probably cheaper to just buy an mt5 and ring

 

[Hood]

Your 4 jaw sounds like it is knackered, you should have even grip along the length of the work piece.
Lots of people ignore using soft jaws on 3 jaw chucks, they associate them more with CNC but they are very handy for things like you are wanting to do. Just remember if boring out soft jaws that they need to be loaded in the direction of clamping or they will not be deadly accurate.

 

[mike os]

Your 4 jaw sounds like it is knackered, you should have even grip along the length of the work piece.
Lots of people ignore using soft jaws on 3 jaw chucks, they associate them more with CNC but they are very handy for things like you are wanting to do. Just remember if boring out soft jaws that they need to be loaded in the direction of clamping or they will not be deadly accurate.

Whch is unfortunate because it has hardly been used....... but explains a lot.......

 

[Hood]

Is it a good make or a Chinese/Indian one? Even these tend to be fairly decent nowadays but maybe it has had a heavy crash which has sprung the jaw guides.

 

[God mode restorations]

Found that today grim..... couldn't find mt5 when I was looking..... also need a locking ring retainer for the chuck mount....... was hoping to avoid that as I can't find one for a Colchester at the mo

I might have to adapt the 3 jaw backplate as it's ******** anyway but it's probably cheaper to just buy an mt5 and ring

What part do you need for the Colchester.

 

[mike os]

L

What part do you need for the Colchester.

Catch plate or spindle nose cover.... really to lock up the nut more than anything, old backplate, faceplate. ...can always machine it to suit

 

[Hood]

L

Catch plate or spindle nose cover.... really to lock up the nut more than anything, old backplate, faceplate. ...can always machine it to suit

You have a lathe

 

[grim_d]

What fitment is your Colchester? Presumably a taper if it has a lock ring

Rdg sell a range of finished backplates for Colchesters if you can't be bothered to make one.

Backplate + collet chuck = win.

Or am I misunderstanding?

 

[mike os]

New is dear.... l0 taper and big back nut 3tpi iirc

Yes have lathe, but not the change gear to cut less than 5 tpi. ... otherwise it would be done already

 

[grim_d]

https://www.rdgtools.co.uk/acatalog...O-Taper--Colchester-Studant-etc--612H485.html

Is that the right one? ~£90 with return customer discount. It's not a bargain but £140 all in with a collet chuck is a fairly reasonable price IMO for something you will likely have for the rest of your life.

You will use a collet chuck so much that it will pay for itself in no time at all.

 

[Hood]

New is dear.... l0 taper and big back nut 3tpi iirc

Yes have lathe, but not the change gear to cut less than 5 tpi. ... otherwise it would be done already

Must be a Student with the L0 taper then, don't think they went less than 4 TPI even with the change gear.

 

[grim_d]

It's a bit crap that the lathe is incapable of cutting the thread on its own spindle nose!!

 

[Hood]

6TPI for a L0, still need the gear though for less than 8

 

[mike os]

6TPI for a L0, still need the gear though for less than 8

Knew it was something like that. ..... memory is shot

 

[mike os]

It's a bit crap that the lathe is incapable of cutting the thread on its own spindle nose!!

It can if you have the change gear.... but iirc it's only for about 3 very coarse threads and you never see them. Everything else is cut from the standard gearing and the thread cutting box

 

[grim_d]

Maybe @pete can help you with a gear?

I'm one to talk. I have literally everything to cut gears for my Harrison apart from the effort to actually do it.