Lathe die head Wanted!!

Why not buy long threaded rod? It comes in 10 foot lengths.

What size? You might be better off simply purchasing the all thread, but you can find geometric die heads on ebay. It took me about 4 months to find one that a) I could afford, and b) I could rebuild to work.

Why in the *heck* are they using 5-40 screws in those things!?

Jim

================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================

Agreed! I've got some, but I have uses for them, and got them by haunting eBay for a while. And as I use them (on a bed turret), there is a limitation of about four inches before the end of the workpiece would hit the vertical rod which runs through the center of the turret for clamping it during the cuts.

If you mount it in a quick-change boring bar holder, you could probably do it, but there are other problems:

1) How far will the carriage travel before it has to stop? It will open the chasers and stop cutting at that point. (How does this compare to the needed length of the threaded workpiece?)

Any attempt to unclamp the workpiece and re-start the cut after repositioning will probably generate problems, though you *might* be able to close the chasers onto an already cut area.

2) How will you feed the carriage?

If by threading feed, there is a chance for a slight error between the leadscrew feed and the thread pitch being cut by the die chasers, which can either pull the die head ahead enough to trip the release.

Or -- there is the possibility that the feed will be faster than the thread, in which case you will have excess force which will probably damage the threads being cut.

If you are feeding the carriage by hand, there is a better chance of things working, as you can keep up with the feed by feel.

3) How are you supporting the workpiece which has already passed through the die head? If it is truly long, you will need a steady rest beyond the die head to keep it from whipping (unless you are running *very* slow.) And the fingers of the steady rest will probably damage the already cut threads.

Long threaded rod is usually made in production by *rolling* the threads, not cutting it, and I'm not sure what the lathe is like to allow such long rods.

As long as the needed thread is a standard one, and the rod doesn't need any other features (bearing points and such), commercial rod is probably the better choice. Even Home Depot has 24" and 36" all-thread available. If you need it longer than that, you'll have to find an industrial supplier somewhere, I think. But if you need it longer than that, it would also be a serious pain to do on a lathe, with or without a Geometric die head.

Perhaps some more details -- length, diameter, and thread form (e.g. standard V threads or Acme or something else), would give people more of a starting point for advice. Also, some information as to how big a lathe you're working with, and what other tools. You *can* do the job within reasonable length limits with a single-point cutter, a live center in the tailstock to support the free end, and a follower rest to support the workpiece very close to where the cutting is being done.

Geometric die heads *can* be found from time to time on eBay -- but they may not do just what you need, so it would be good to be sure that one would serve your needs before purchasing one -- even if you luck into one in good condition for $300.00 or so. (Price is also a function of the diameter of the workpiece. Mine are 5/16", 1/2" (rare),

9/16", and 3/4", and after you get that, you still probably have to purchase a set of chasers for the thread you intend to make. The odds are against your eBay find having just the right chasers in good condition. And a set of chasers will go for something between perhaps $70.00 (for ones for the 5/16" die head) up through $140.00 (for the 3/4" die head). These prices can go up or down depending on whether you hit Grand Tool during a clearance sale, or whether you have to order a special that your vendor does not normally carry.

Good Luck, DoN.

To encourage the sale of 5-40 chaser sets? :-)

Enjoy, DoN.

I've found that the smaller die heads tend to go for *more* money. Possibly because they are rarer, the small ones are pretty fragile and maybe never survive a stint in a production shop.

Jim

================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================

Will that work for you? I almost bought it for myself. Oh I just remembered that I have a large Landis head out in the shop that I have never used. If you are interested let me know and I will send you some pictures.

Richard W.

1" die head? 1-3/4" shank? Way too big for *my* machine. (But then, I wasn't the one looking for it.) The important thing is whether chasers are available for that to cut the intended thread. (Not that the thread is known to anyone except the original poster, yet. :-) But the bigger the die head, the more the (new) chasers cost.

Other than that -- the current price is attractive.

Enjoy, DoN.

Like don asked, how long a piece do you need? Longer than a few inches and a die head won't do it.

If it is a non-standard thread you proably won't be able to purchase off-the shelf chasers anyway. Single point it with a follower rest would be the way I would do it.

Jim

================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================

I went out and looked and the die head I have is a 2 Landmatic. Cuts 3/8" to

1 1/4" threads. It also has a 2" shank that appears to be bolted on.

Richard W.

DoN and I have different models of Clausing lathes and we both have bed turrets. Mine (on a 5914) must be different than his, though, as there is

1" of daylight all the way through the bore on one station to to the bore on it's opposite side. IOW, it would be possible to thread a pretty long piece with a die head, providing the OD was small enough to fit therough the die head shank bore.

snipped-for-privacy@msn.net

Yes -- quite different in that. There is a threaded stud up through the center of my turret, which passes through a disc and has a nut with a single lever handle to tighten down so there is *no* play in the turret head for heavy cuts. Thus on my turret, the limit is about

3" plus whatever extension there is beyond the turret's face.

*And* as long as you had some way to capture and steady the free end of the workpiece as it passes through the turret. The other problem is that the total travel of the turret ram is about 8-10" (I think -- maybe a full 12"), and if you use the back-most two inches, you will pick up the pawl which will try to rotate the turret as you pull back -- which could be very awakward with a long workpiece passing through it.

I guess that you could limit the travel and use the lever collet assembly to lock and unlock the collet to pull more stock through the headstock.

But we really don't know what kind of lathe the original poster ( snipped-for-privacy@msn.net) has, nor whether it has a turret of any form, or what the diameter is. Though we now know that it is an Acme thread, and I've never seen a set of Acme chasers for a Geometric die head. I guess that they could be purchased, but I would think that you would want a larger die head to handle the extra cutting load for the Acme thread form -- let alone the extra cutting force needed for a good bronze.

"Larger than a standard diameter" may well mean also "larger than any die head which will fit in my turret", and thus "possible problems in most lathes which will fit in a typical home shop." My largest die head which I've used is a 3/4", with a 1" diameter shank. I think that it may have a full 3/4" diameter clear through the shank, though I've never actually measured it. But that could be a limiting factor.

I agree. I can handle up to 24" long between centers, and with a single point tool, plus a follower rest, I can cut Acme threads on that up to perhaps 6" diameter. If it is 1" diameter or less, I can pass it through collets, and with a steady rest replacing the turret or tailstock, I can single-point any 24" long section. Beyond that, by unclamping and reclamping, and taking a lot of time tuning the feed to pick up the previous pass, I can probably continue the thread -- but each re-clamping increases the chance for a mistake which would spoil the whole thing.

Using a chuck, I could pass a full 1-3/8" through the spindle, but could thread somewhat less length at a pass, thanks to the loss of space taken up by the chuck.

The longer it gets, the more likely to have problems with whipping -- (and the smaller the diameter the more likely to have those problems -- but if you have whipping with a large diameter, you have major destruction -- including possibly of the lathe or yourself.

So -- yes, knowing about the approximate dimensions -- *and* the size of your lathe -- do make a difference. The more we know, the better our advice can be.

But if you have to be secretive about it for whatever reason (perhaps a non-disclosure agreement?) so be it.

Knowing that it is larger than the largest die head your lathe will handle is one important thing. Knowing that the overall threaded length is greater than the travel of the carriage on your lathe is another important thing.

If you're trying to do this with a 1-1/2" die head, and a Sherline lathe, we will all turn our backs and wait for the final outcome. :-)

Enjoy, DoN.

Ah, mine is a hardinge DSM-59, where the turret is basically conical, and mounted at an angle. So there is no daylight available! :)

I think the original poster is certainly being less than informative about the setup involved.

Jim

================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================

I have two good die heads that I have no use for. One is a genuine GEOMETRIC, the other a good knock off. Plus I have a whole case of oddball threading dies typically used in the locksmithing trade.

If you want an independent review of the items, I can bring them down to MarMachine in Costa Mesa.

I am SURE he would agree that two heads and 25 die sets are worth $200.

I've got manuals for both available and see what you mean about the turret head lock (threaded stud) on yours. Mine has no such feature but seems pretty sturdy nonetheless. Haven't taxed it much yet, except for using it to drill 1/2" holes about 2" deep in SS and it had no problem there.

Some of the Logans had "pass through" turrets, but the DV-59 is a true Second Ops lathe, and is not really a "turret Lathe" though it has a turret.

There is a difference, moot for the most part..but a difference.

Gunner

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote!" -- Ben Franklin

GACK!!!!!

Thats one FINE price! Somebody snag it NOW! before he changes his mind.

Gunner

"Democracy is two wolves and a lamb voting on what to have for lunch. Liberty is a well-armed lamb contesting the vote!" -- Ben Franklin

If the machine was intended to be a turret lathe, as in my W&S, B&O and Garvin, there are two turret stations that line up with a hole in the pivot post, allowing almost any length to be passed through it. I have one die head limited to a 3/4 inch length, but both of my geometrics will pass any length. All three of my machines also accept

1" shanks. They may be old, but it's nice when things work.

A turret lathe of that size is outside my experience. As gunner has correctly pointed out, my DSM-59 was really designed as a second op machine, but has a bed turret that can be fitted.

To save space the turret is mounted with its axis at an angle to the vertical, and is basically cone-shaped. So the tools rotate up as well as around.

I guess on a larger machine, the limiting factor would be turret stroke length. If it were a true bed turret then that would be pretty much the working bed length. I still find it hard to belive that the original poster has such a turret lathe handy to mount a large capacity die head on.

But hey stranger things do happen. Around here.

Jim

================================================== please reply to: JRR(zero) at yktvmv (dot) vnet (dot) ibm (dot) com ==================================================