Tailstock die holder

After posting a question about cutting a m10 thread, some of you suggested macking a tail stock die holder.

So here goes.

This project was born from needing a tool to make a tool. As is so often in the home workshop.

Anyway i was making a toolpost mount and needed to cut a m10 thread. Didn't have a die so i orded one. When i came the OD was 1.5 inches. Didn't have a die holder big enough. Order one no no make one. So i started to make one out of god knows what HARD HARD steel i had. As i was in no rush and not having used the 4 jaw cuck i dug it out and after 10 minutes faffing about got in running within about half a thau. Good enough for me. Some pictures

Started out by turning the OD to what seemed to be a decent size to accommodate to handles.

Drilled and bored out the the ID to a perfect fit.

Using the DTI to get to the correct depth.

In this picture the die isn't pushed all the way in. When it is its perfectly flush.

Then marked out, drilled and tapped the 3 securing / adjusting screw holes.

The plan was to cut it off the length, drill and tap 2 holes 180 from each othe and add handles. Job done.

Well not so. After taking advice from forum members its back in the 4 jaw running true and ill drill and bore through the middle and turn it in to a tail stock die holder.

Is my skills are at the beginer level im not going to make a mores taper arber. My plan is to bore the through hole 1 or 2 thou over the OD of my tail stock and use the extended tail stock as the running arber if that make sense.

More progress pictures to follow when i get back in the work shop. Hope you enjoyed read the exploits of a beginner and any advice more than welcome.

Thanks

Steve

Nice work. I once bought a tail stock die holder and regretted not making it myself. Hope to see yours completed soon,

Mark

Did you leave a small allowance for opening the split die up?. On my 1.5" the bore is actually 1.508

The smaller ones are 1.003 for 1"

0.8175 for 13/16"

and 25.11 for 25mm

I have no idea what the official standard is.

Perhaps one of our toolmakers will chip in and tell us.

regards Martin

I didn't at first it was such a thight fit i had to get the heat gun on it to get the die out. Then the penny dropped and I left about 5 thou clearance.

Thanks

Steve

You need clearance to expand split dies for the first cut. Then they are closed down a little at a time to get the final exact size. This gives the best finish on the thread. I have a set, but have never used them, as I prefer to single point using the lathe.

Most commercial Tailstock Die Holders cater for a number of sizes of die OD

The body, which carries the individual die holders slides on an arbor.

A handle is screwed into a tapping in the body, that can rest against the toolpost, to prevent rotation.

The fit between the body and the arbor is fairly slack so that the die can centre itself on the workpioece. The fact that the body carrying the Die can slide lessens the load on the newly cut thread, in that it does not have to drag the Tailstock along the bed.

Take a look at the offerings from Arc Euro, Chronos, Warco etc to see the body and the holders for various sizes of Dies.

Howard

+1 for Howard's point. A sliding die holder is preferable to one fixed to the tailstock. I have a Wardson Easi-Thread which has about a 4" slide travel and has a clutch which disengages the die when the lever is released. Reverse the headstock spindle and the thread winds out of the die and resets the clutch. Wonderful piece of kit!

Edit of spelling mistakes!

Edited By Oily Rag on 07/06/2020 22:53:19

OILY RAG: The Wardson Easi-thread sounds like an interesting bit of gear. I have not been able to find any information on the internet about these. I did find a Wardson Esi-thread which is for threading sewing needles. Not a lot of use

Can anyone point me to a source of information or supply of one of these?

Chas

Here is a sliding die holder that I made. The body slides on a steel rod that is held in the tailstock drill chuck.

It was easier than turning a M2 taper and permits it to be used in my mill.

I added the (weak) spring to help it along but not sure that it really needed it.

* Danny M *

The Hemmingway kit is another good design and a nice machining exercise, uses a cone clutch and sliding die holder with interchangable heads for different size dies.

You may well be right about thread finish but I believe best practice is to aim to set the die correctly at the outset, particularly if multiple threads are to be cut.

For concentricity drill and ream the hole for the tailstock bar at the same time as the bore for the die. When I made my first die holder for the Myford I just copied the commercially made holder that was on a Boxford at work,,steel body with knurling ,1/2 inch hole through the centre ,the support rod was held in the tailstock chuck ,and cross hole for a tommy bar , the knurling was so that small BA theads could be threaded by just gripping the holder in your hand,olt quicker than using a tommy bar. After over 50 years I have a number of holders to hold dies from 10 BA to 3/4 BSP some are made from steel the rest from aluminium alloy bar (HE 30 ) they have withstood hobby and 25 years commercial use. things I have learnt, three equi spaced tommy bar holes are easier and quicker to use on a larger lathe, one of my tailstock support bars has hole down the centre so that long small threads dont foul on the end of the bar. Long threads can also foul on the tommy bar ,so one of my tommy bars is made from larger dia material than the bar hole in the die holder, the end of this larger bar is reduce in dia for a short length so that the tommy bar only enters the bar for a short distance and does not foul the workpiece. the die holders being alloy are lighter so can have thicker wall around the die and the tommy bar does not slip out. Do NOT allow the tommy bar to rest on the lathe bed , if you require a torque stop to stop the holder rotaing ,allow the tommy bar to rest on a length of steek bar held in a tool holder, necessary when cutting lots of course threads.Why a/alloy ?they are lighter,a quantity of material was/is available and if you should accidentaly drop one on the lathe bed they do not any damage, heavier Work is done on my Colchester which having forward/reverse clutches makes threading easy and quick,and the quantity of holders allows the most used dies to remain set in their holders.

Lipscombe Chas:

Here are photos of the box the tool came in and the tool itself.

There were 3 die holders originally but I made a 4th for larger dies (1.5". The mandrel is 2MT and there is a pin (visible near the end of the parallel shank) which engages in a slot in the sliding part of the tool with a rotating circlip to 'lock' the tool onto the slider. I have a rack operated tailstock so engage the die onto the workpiece whilst holding the lever vertically. The apron needs to be clear of the handle to allow it to rotate about 90 degrees (towards me) to disengage the clutch. I always thread in 'back gear' to give plenty of torque and to allow for slow threading. The nice part is you can thread upto a shoulder with no concerns as the tool when abutting the shoulder turns the 90 degrees and disengages instantly. Reversing the lathe lifts the lever back tothe vertical and the die holder re-engages and winds the die off. The materials I commonly cut are A286 stainless and T614 Titanium. The lever is long enough to be able to comfortably hold by hand whilst cutting the thread.

I can't remember where I got this tool from but seem to think it was from J&S Industrial at Wednesbury in a 'clear out' they were having. Most likely about 10 or 15 years ago! I have seen one other at an agricultural engineering workshop nearby to where I live - they used it for making studs for agri equipment on a regular basis. Once set up it will knock out studs in a fraction of the time.

Definitely not a sewing machine threader!

Chas:-

Just found this at an auction - which has unfortunately ended now. It went for £19 + VAT +Auctioneer premium

**LINK**

Looks to be almost new:-

The pipe threader was also part of the Lot!

Thanks Oily Rag! I was right, it is an interesting bit of gear Threading up to a face is particularly interesting.

The only problem now is where to get one!

Chas

Thanks for all the advice, this project is now complete. Well as for the M10 die its is. I still want to make adapters for the other size dies i have but that will be for some other time.

George Thomas made holders for all his dies and his policy was 'set and forget'.

Neil

Question: Are dies made at the correct size in their ‘neutral’ state, or do they need opening slightly for the nominal thread size? I’ve made my die holders a sliding fit for the dies and they are (mostly) easily extracted by a gentle tap on the arbor.