straight shank 3/4 inch toolholder system?

Has anyone heard of a toolholding system using 3/4 inch
straight round shank holders? I've got a 50-year-old lathe
whose turret tailstock has 6 sockets each 3/4 inch in diameter
and about 1 inch deep. I'd really like to find a ready made
holder for morse taper #1 or #2 tools, since I have live
centers and boring setups, etc. with morse taper shanks.
I have seen much larger straight shank bushing/holders for
1mt and 2mt - 1 1/4 inch and up, but I'd rather not have
to turn those down while trying to maintain concentricity.
Anyone have a clue? Or do I have to get someone to make
a set of bushing/arbor/adapters for me?
thanks!
Reply to
gwes
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--IIRC the Myford turret uses 3/4" straight shank holders; try them?
Reply to
steamer
Alas, all I could find were mt2 or screw thread sockets. I did find a number of makers of straight shank CNC sockets but they are all at least 1" in diameter. I've emailed several to see how much they'd extortXXXXcharge for a few with smaller ODs.
Reply to
gwes
According to gwes :
It varies with the size of the lathe. My 12x24" Clausing has 1" sockets in the turret. I've got lots of tools which mount there, some with native 1" shanks, others with adaptor collars to fit 5/8" or so shanks to the 1" sockets.
Hmm ... I'm not at all sure that a bed turret (like mine, at least) would be a good choice with live centers and such, though I do have some sockets for converting 1" to #2 MT at least. Yes, I would use it for a drill prior to boring or reaming, but I can't apply sufficient force to use with a live center, let alone not having a way to lock it in position. Mine has the turret ram feed with a rack-and-pinion gear connected to a four-armed spider -- good for cycling the turret quickly, but not for applying high force full time. Does your turret have a way to lock it forward?
In the turret, I use things like:
1) Drill chuck
2) Box tools.
3) Geometric die heads for quick threading.
4) Center drill in a depth stop for double functions.
5) T-format knurling tool.
6) Releasing tap holders for internal threading.
But I don't use centers there. When I need to turn work between centers, I pull off the bed turret and put on a standard tailstock (which I had to hunt down from eBay), since that is what a standard tailstock is best at. The bed turret came with my lathe, with matching serial numbers. The tailstock, obviously, did not.)
And -- because a bed turret for that size lathe is *heavy*, I made a narrow table (of 4x4s and 2x4s) at just the right height to slide the turret onto from the back end of the lathe bed. The standard tailstock is a lot lighter, so I just lift it into place when I need it. The base of the table has two 2x4 rails running the length to both stabilize the legs and to support several chucks when not in use.
Make a blank, and step drill it undersized for the Morse taper, and mount that in the turret (making a mark for which side is the top), then put a Morse taper finish reamer in a collet in the headstock, and feed the blank over it to form the Morse taper socket. This will assure that it is concentric with the spindle, even if the socket is a bit off.
Then, (*before* you get something stuck in it) mill a through slot for a drill drift key.
It would be nicer to have it hardened and ground, but more difficult to maintain the accuracy you need.
You get a real tailstock for work needing the centers. For the rest, you can make your own adaptors (resulting in a more precise match of centers) by following my hints above. Remember to mark them for which side is the top, so you retain your center accuracy.
Good Luck, DoN.
Reply to
DoN. Nichols
Look for turret lathe tooling, though you may not have much luck finding MT adapters.
Reply to
Mike Henry
--Yeah, well, FWIW I bought my Myford turret used and I've been making my own toolholders for it. This may be your best bet, particularly if you've a yen to do anything unusual..
Reply to
steamer
Thanks to everyone who's answered so far! Here's what I found:
For holding things like drills & other round things, a 3/4" bar which holds ER16 or ER25 collets. That gets me up to about 1/2 inch.
For holding things with tapers, Victor Machinery Exchange has various Morse Taper sockets in -soft- cylinders. I have a drill bit with taper mount which I will chuck in reverse (mount outwards) and see if the socket fits sufficiently concentrically. If it does, I can turn down the end 1" suitably. If not, I expect I can center it in my 4-jaw and turn it there. Failing this, I'm sure I can find someone locally who can do the job.
There's a part (#68711) mentioned on the Collis Tool website which is part of a larger toolholder. I can't find any more information on their website other than a cryptic 3/4" shank 1 MT socket. So I guess a phone call is in order.
And a screw on the gibs of the slide on the turret tailstock body will hold it in place - a small modification for a lot more utility.
Reply to
gwes

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