Well, that addresses some problems I had finding a set of blocks I liked for my ER32 collet sets. Could you provide a little more detail on the internal locking collars? A photo or two should do it. :)
I considered something like that, was looking to see if anyone made them, and not finding any. Not at all sure I could make the blocks for the standard external locking rings. Nice work!
Bill in OKC
On Saturday, September 7, 2019, 4:45:30 AM CDT, John Lindo <bechetboat@...> wrote:
The late John Stevenson developed the ER 32 collet holders and was an overnight success.
His original design still manufactured commercially was based around the ER 32.
The problem being when buying commercial blocks the ER 32 locking collar has a larger diameter than the 4 or 6 sided
body. this means when clamping the blocks horizontally in a standard mill vice the locking collar touches the jaws
before clamping onto the 4 or 6 sides.not really an issue but means using packing pieces between the block flats?
and the vise jaws.
i wanted to find a solution, the easiest being, make the blocks larger across the flats than the diameter of the locking collar.
I also wanted to use my ER 25 collets in a small 2" toolmakers vise.
Solution, make a set of blocks with an internal locking ring that pushes the collets down the taper of the body.
Set about doing this and instead of 4 flats I developed 8 flats and a traditional 6 flat holder.
So the body was a standard lathe op, internal taper and screw-cut with the ELS.
The internal locking ring, screw-cut and a 30 degree cone that pushes onto the collet.
The block flats were milled and finish cuts were done using the Electronic Step Indexer.
Using a ER 32 holder in the indexer spindle and a 16 mm ground bar stock, the internal block was clamped onto
this.
All worked out well, TIR of the flat variance from c/line within 0.0025".
I hope the photos can explain better.
--
John
Bill in OKC too