Tailstock larger workholding

[aRM]

Gentlemen
This is the right place to pose my quandary, given the deep dimension of experience and sheer knowledge prevalent.

The first part ......
What's the best way to hold bigger Tooling in the Tailstock, say about 1" to 1 1/4" diameter, without expending on another Large Keyless Chuck ?
Our Tailstock has a MT4 and we have Drills that Capacity as well.
We were thinking in the line of Endmills etc.

The second Question ......
Has anybody made one of those so-called LIVE MT (so-called-Chuck-Holding) Mountings for the Tailstock as well ???
Something mounted slightly smaller than a full blown 3 Jaw Chuck !!!
We have seen some here with a large Chuck Mounted in the Tailstock, which we don't have at present anyway.

And further .....
We have a small 3 Jaw ( 3", I think ) Chuck on a 5C Collet which we would like to make a little more versatile and wonder whether this could be Mounted in the MT4 Tailstock as well - with an adaptor of course !!! Cutting bothe MT4 and the Internal 5C THREADS should be a good challenge, if we could only ascertain the ID of the 1.041 x 24 THREADS ???
Have the so-called Bible, Machinery's Handbook, 21st Edition, nothing on 5C COLLETS, drew a blank on above Thread Dimensions etc. Zilch. Zero ??? Don't understand ??? Will try the Hardinge site, if any worth there. Better still, should just buy a TAP, if we can source it !!!

TIA
aRM

[John S.]

First part.

ER40 collet chuck with MT4 shank http://www.ebay.co.uk/itm/281397093260 ER40 normally goes to 25mm in the sets but you can buy 26 to 30mm collets to also fit this.

Second part.
Yes but use a 4 jaw, not a three jaw it's more versatile if you have to hold worn or say welded shafts.





That's an MT4 with an 8" 4 jaw on it, one bearing is in the backplate and one is sunk into the back of the chuck.

Further.
Just put the 3" chuck on a parallel shank and hold in the ER40 collet chuck.

[PixMan]

John,

That tailstock chuck setup is brilliant! I'd love to have one like that. Someday, perhaps.

[aRM]

(09-01-2015, 11:35 AM)John S. Wrote: First part.

ER40 collet chuck with MT4 shank http://www.ebay.co.uk/itm/281397093260 ER40 normally goes to 25mm in the sets but you can buy 26 to 30mm collets to also fit this.

Second part.
Yes but use a 4 jaw, not a three jaw it's more versatile if you have to hold worn or say welded shafts.





That's an MT4 with an 8" 4 jaw on it, one bearing is in the backplate and one is sunk into the back of the chuck.

Further.
Just put the 3" chuck on a parallel shank and hold in the ER40 collet chuck.

Thanks for the prompt response John S
That's a very good suggestion on the ER40 COLLET CHUCK. Just up our alley as we have these Collets on our Drill Sharpening machine to 25mm. Only thing is U have suggested one with an M16 Thread at the rear which we'd need to plug with the Tailgate or what'-Ya'-ma call-it, to stop the Chuck from turning in the TAILSTOCK under duress.

Really don't know if the 3" 5C can be separated as we as we think it is integral. If it can be, then Bobs Your Uncle, U gave us the dream-machine tool.
All the best
aRM