Eastern Geometric head issues

[zimbo]

Morning all,

I am new to geometric heads and have been out witted with this particular one that came with loads of chasers, that I purchased several years ago whilst visiting the states. Maybe I purchased a fancy paper weight.

It’s made by Eastern Machine Screw Corp. Style DMLN. Size 1101 & has a number stamped on its side 3014. The shank is 1”.
What does the DMLN style refer to? Día of work piece or just style of chaser. I have made an adapter to hold it in my lathe tail stock.

Web doesn’t have too much info regarding this, other than sales. I did post a while back how to open the die head to insert the chaser blocks and all that is working fine now. Hidden detent ball bearing!

What I am stumped on is what diameter range of studs can I thread with this head? Like I said, there is a very large range of chasers I got, mostly fine pitches, odd balls I have never heard of, so assume die head was with someone producing specialist equipment.
So, I have 3 types of chaser blocks. I have installed both the 12mmx1.25mm chaser and ½”x13 chasers on all 3 blocks and when the die head is closed, doesn’t even come close to the dia. of the rod I am wanting to thread. E.g. when the 12mm is installed and is closed measurement between the opposite chasers, say 1&3 closed is 22.36mm & open is 28.09mm. I have rotated the chasers on all 3 blocks and the numbers are similar.

The number on the head indicating which slot is 1,2,3 & 4 is stamped in the middle of each slot so a bit confusing which slot it’s referring too, left it right. Have rotated the blocks to both left and right of corresponding number, still the same. Seems maybe the blocks or chasers are too short or the chasers were to thread larger dia. stock?The photo below shows the engraving on each set.
Top - 101DN/0-1-2 59 94
Middle -101,17-32, 3 -4
Bottom – HA6, (HA7)1101, 25-32
Do the 17-32 & 25-32 refer to the thread pitch?
Appreciate you help. TIA
Greg

Showing die head open.

Showing die head closed.





Showing backs of chaser packages

Which slot is referring to 1? Left or right? Yes blocks currently in wrong position


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[calvin b]

Zimbo Sir,
Can you post a picture of just one of the chasers and a corresponding empty slot in the die head ?
I think you may have "k" style head. But then again I could be wrong. The chasers you show have been heavily modified.
Stay safe
Calvin B

 

[L Vanice]

Geometric is a brand name for a line of die heads and collapsing taps that has been owned by several companies since the original design around 1900. They have proved to be excellent devices, especially the style D die heads, which are still very popular and have been copied closely enough that the copies can use Geometric D chasers. Of course, others have made the D chasers.

Then there are the less popular types of die head, made by Landis and Eastern Screw Machine and probably some even more obscure. They all made good die heads that worked, but they never became as popular as the Geometric heads. They used chasers and possibly also chaser holders that are nothing like the Geometric D chasers. Some people think that any die head can be called a geometric. But there is no such thing as an Eastern Geometric die head. Once you start looking for chasers, you quickly learn that not all die heads can use Geometric D chasers.

I have lots of Geometric and copies of Geometric D type heads in various sizes. I got my first one, a 9/16 D with a 1900 patent date, but still working fine, in 1982 or so. I soon learned that the three Landis heads and one Eastern Machine Screw head I thought were good deals at the time would never see any use in my shop. I did actually use a Geometric K head for one job, but it needed scarce chasers, so I sold it.

I still have my Eastern Machine Screw Type DML head, which is in excellent condition. It has a 5/8" shank with a 5/16" through hole. The center hole in the head is 5/8", but I suspect the capacity is probably much less, like 5/16". It has a set of 1/4-32 chasers in it. The chaser holders are marked NP 64 and have a Cleveland Twist Drill logo on them. Maybe Cleveland owned the Eastern die head design at one time, so you might find the chasers and holders are listed under Cleveland, as suggested by the brand name on some of your chasers.

On my head, the slot numbers are close to one slot. I think it does not matter which slot you call number 1, but it is important that the chasers are placed in the slots in the same order as the slot numbers. Just decide which slot will be number 1 and insert the chaser/holder assemblies accordingly.

I did a little research and found that Eastern Machine Screw used the trademark "H&G" for their die heads. There is a listing for some H&G 100 series chasers on eBay now that states, "these will fit any head that uses the 100 series chaser. this would include style DMN, MM,MMV,DMLN,DMS,DMSL,TM,TMM AND SSM Style die head .there may be others these fit as well for the 101,1101,and 102 size heads. please look carefully at the pictures and compare yours to these. I am going by information from a sales brochure and may be wrong on the size head their fit."

Here is the listing. https://www.ebay.com/itm/383509308180

I also saw on eBay a die head like mine that was said to be an H&G size 00, perhaps a reference to the B&S 00 screw machines that take 5/8" shank tooling.

Larry

 

[Illinoyance]

Did H&G die heads use different holders for their chasers? That could allow different diameter threads with a single set of say 20 pitch chasers.

 

[L Vanice]

Did H&G die heads use different holders for their chasers? That could allow different diameter threads with a single set of say 20 pitch chasers.

The answer is in the H&G chasers and in the chaser packages. You can see each chaser is marked with a diameter and pitch.

The Landis tangential die heads used chasers with just the pitch on them. They need different holders for different diameter and pitch ranges because the pitch angle changes with diameter for the same pitch.

Of course, you can fiddle the pitch diameter a little with the head adjustment on a Geometric D die head. I cut .275-40 threads with 1/4-40 chasers.

Larry

 

[JST]

The H&G, at least mine, do not have a lot of adjustment range on the head, so it is very difficult to get a different size at same pitch. They basically have enough range to cover the fit classes on the coarsest pitch.

The chasers are made sized for the diameters. There is no good way to "fiddle" them to cut a different size

But mine are rather old ones, and newer might be different.

 

[Greg Menke]

I have a couple UK Coventry die heads, pretty much the same ability to adjust a bit over/under to compensate for chaser sharpening and tweaking fits. The J&L tangential heads seem like the might be capable of wider variation of diameter but I've not tried to do that with them.

 

[zimbo]

Zimbo Sir,
Can you post a picture of just one of the chasers and a corresponding empty slot in the die head ?
I think you may have "k" style head. But then again I could be wrong. The chasers you show have been heavily modified.
Stay safe
Calvin B

Some of the chasers I have been wanting to use.


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[zimbo]

Calvin. Here a couple of shots of the open slots without the blocks.







Hopefully that’s what u wanted to see.


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[calvin b]

Zimbo Sir,
The resolution of the pictures is not great enough for me to identify what you have. More detailed photos would be a help. I suspect what you have has been modified..
Til you can post better pictures you could browse these good folks web site and try and identify what you have..
Quality Chaser Company
Hope this helps.
Stay safe
Calvin B

 

[john.k]

i once bought a 2 head Landis machine from the railways......when I was picking it up they hit me with a loading fee......anyhoo ,I complained about the fee ,and the forklift driver brought me out a pallet of dies in cardboard boxes.....2 tons of dies......Not a single one of those dies fitted the Landis ,or anything else I had .......Moral ,unless you see the dies fitted to your head,assume they wont fit.There are literally a zillion different dies/chasers/.inserts/ call them what you will.

 

[john.k]

In any case ,you must have the correct sharpening fixture for radial chasers..The Coventry type often appear on EBAY UK.....Landis tangential chasers can be sharpened by hand ,provided the angles are maintained.