ER32 square collet?

[bentprop]

My problem is this:My 4-jaw chuck is too large to hold 3/8 square stock.
I have looked high and low,but cannot find an er32 square collet.
I thought of making a cathead(?),but doubt that I could make this accurate enough to hold square stock true.
My main reason for wanting to hold square stock in the lathe is to drill and tap the end.Any other work on it can be done on the mill.
Any ideas anyone?

 

[tel]

Interpose 4 packing pieces (one on each side - possibly more 3/8 sq.) and hold them on with a bit of sticky tape or superglue.

 

[Twmaster]

Funny you mention this. Earlier this evening while out in the workshop I was wishing I had a 1/4" hex collet for the ER16 spindle in my Taig milling machine.

 

[Ken I]

Split a piece of roundbar, mill 90° grooves down the centreline.
Use that to clamp stock in your 4 jaw.

Ken

 

[Jasonb]

Or just bore a hole down a bar end to suit the accross corner size of your Sq stock, slit it with a hacksaw and then just hold in the 3 jaw.

J

 

[mklotz]

Until I got square collets, I used to do what Ken suggests. It works very well although you may need to do a bit of shimming from time to time to deal with stock size variation.

 

[doc1955]

What Tel has said. I've done small square stock this way a few times and it works out just fine especially if you have a few pieces to do.

 

[bentprop]

Thanks for he replies,chaps.It's SO simple :big:
Being somewhat of a lazy disposition,I'll go with Tel's suggestion.
The part in question is the piston rod fork for Jan Ridder's simple 2 stroke.
Will post pics when I get the camera back.

 

[bob ward]

This is a bodge but it works for me, I just put the square bar into the appropriately sized round collet. In this case the .375" square is about 13.5mm on the diagonal, into the 14mm collet it goes.

There have been discussions in other fora about hex and square ER32 collets, and I gather that while there is technically no problem with grinding the collets to shapes other than round, the potential sales volume is considered by the makers to be insufficient to warrant making them.