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View Full Version : H&G Die Head adaptable for home shop?



Cannonmn
11-29-2016, 10:32 PM
Wondering if anyone has successfully adapted one of this type for use on medium or large lathes? Big question is what would hold the bar to be threaded, it doesn't seem like something I'd want to do to my tailstock. Maybe a lathe Chuck mounted somehow to the left of the headstock, fastened to something very heavy?

While I'm getting pix uploaded you can see what the die head looks like and read how it works in the patent.

http://www.google.ms/patents/US1937418

https://springfieldarsenal.files.wordpress.com/2016/11/img_4309.jpg

https://springfieldarsenal.files.wordpress.com/2016/11/img_4310.jpg

https://springfieldarsenal.files.wordpress.com/2016/11/img_4311.jpg

https://springfieldarsenal.files.wordpress.com/2016/11/img_4313.jpg

ken
11-30-2016, 01:41 AM
I think the one you show is a rotary type of head. You would want a stationary type of head to use on your tool post or tailstock

Spin Doctor
11-30-2016, 05:55 AM
One possibility is to mount some type of centering vise on the cross slide. The ones meant for shaft work come to mind. Mount the Die Head in holder made for it in the spindle. This would actually allow you to cut threaded shaft or rods that are quite long. We used to use a Landis Thread Cutter to make long threaded bars for both dis-assembly and assembly purposes. That's how they are set up

Cannonmn
11-30-2016, 07:33 AM
One possibility is to mount some type of centering vise on the cross slide. The ones meant for shaft work come to mind. Mount the Die Head in holder made for it in the spindle. This would actually allow you to cut threaded shaft or rods that are quite long. We used to use a Landis Thread Cutter to make long threaded bars for both dis-assembly and assembly purposes. That's how they are set up
Thanks. Thought I had a geo type but if so it is hiding from me now. Yes this H&G is an all-spinning type, easy to tell since there are no levers or other projections sticking out. The ability to thread long rods is attractive, think I'll work on this as time permits. I'll try hard to get something to work that attaches to the toolpost or compound, lacking anything but tailstock that fits on the ways.

JoeLee
11-30-2016, 08:01 AM
Do the dies have a starting taper to them??? Doesn't look so from what is shown in the picture. I'm guessing that the taper is on the inside and the rod stock is fed through the shaft end of the die head which would also act as a guide. Like a bolt die.
A working video with this in action would be interesting.

JL.................

Cannonmn
11-30-2016, 08:45 AM
Starting taper is on the face/front end, is about 30 degrees for 1/8", but definitely where threading meant to start, as back/inside end is perfectly square. Will def make video when/if it gets up and running, will post link here. Cannonmn has about 350 vids on YT now so I almost make videos as a daily function.

JoeLee
11-30-2016, 10:55 AM
OK, just curious. I've seen these before in screw machine shops but never saw one in action.
From what I can see in the pic the dies don't look like they have any starting taper. But I'm comparing what I see to a hand hex die.

What's the deal with the elongated slots on the side with the SHCS ?? also are those springs inside the housing ??

JL................

Cannonmn
11-30-2016, 01:19 PM
OK, just curious. I've seen these before in screw machine shops but never saw one in action.
From what I can see in the pic the dies don't look like they have any starting taper. But I'm comparing what I see to a hand hex die.

What's the deal with the elongated slots on the side with the SHCS ?? also are those springs inside the housing ??

JL................

Taper I described above, for construcion details take a look at the patent drawings linked in first post, they are much more informative than I would be.

Cannonmn
12-02-2016, 07:43 AM
I couldn't figure out how the installed 5/8"-18? Die wafers would move from the position they were in when received, 7/8" diameter, to the required 5/8" diameter. I read some of the patent text, linked above, then compressed the rear flange of the outer collar toward the front of the device with both hands. It took maybe 60 lbs. pressure, but the collar moved 3/8" toward the face and the 4 jaws moved inward to make a 5/8" diameter, and locked in that position. I released them by pulling the rear flange rearward as hard as possible by hand, and the jaws snapped open to 7/8" again, with a bang. The device is bistatic, meaning it is only stable when jaws are fully open or closed, anywhere in between requires considerable pressure on the spring system exerted via the collar.

I'll have to read more of the patent, or experiment more, but each Chuck jaw is marked on the outside "102 D.H. 17/32. 3/4." So the jaws are adjustable in that range. The 90 degree segment of the face marked "4" has a small Allen screw recessed in it, and there's another in line with it on the side of the device, so maybe those are for setting and locking the setting respectively, but in which order I don't yet know, they're both in very tight now. Will add some penetrant and try later, I really hate to damage important screws.

Anyway, now we know why there isn't much of a starting chamfer at either end of the Die inserts (I called them wafers above.). No chamfer is needed, when enough force is applied on the collar in the direction of the face the sharp thread-cutting inserts are forced to dig into the round stock until (head would be rotating at this time) they lock in place for the duration of the thread-cutting stroke.