Threaded Norman Toolpost

Have been pondering this Norman Toolpost - the block and the post are both threaded to allow for tool height control.

Locked at the top by a lock nut on the post.

But if you are cutting towards headstock, then surely the block could be pushed back towards the headstock as there is nothing underneath it to stop it it could rotate on the thread and it might simply drop away from the lock nut ?

Did anybody apart from the author ever make this one ? How did you stop it unscrewing ?

Gotta be a few different ways of doing it, however was wondering if I had missed something in the text

EDIT : Think I got it - relies upon the pinch bolt to squeeze it tight ? Would that be good enough ? That way no lock nut required and  the vernier arrangement is easier to understand.

Bill

Edited By BW on 10/08/2019 08:32:16

Edited By BW on 10/08/2019 08:33:41

Edited By BW on 10/08/2019 08:51:03

Does the hex-headed screw pinch the body enough to lock it ?

... or is it just to improve the fit of thread ?

MichaelG.

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Edit: I think we can safely assume that you didn't build it,

... so; where does the image come from ?

Edited By Michael Gilligan on 10/08/2019 09:01:07

Hey Michael,

Think we were posting at approx the same time. I think thats it, will read the whole thing again maybe I missed something.

EDIT : Scanned the image from the magazine page. Got a whole heap of magzines and have been trawling through them for interesting things to have a go at.

Bill

Edited By BW on 10/08/2019 09:04:04

Seems very limited, much better to have a QCTP or a 4 way toolpost in my opinion.

Tony

Hello BW.

I have two of these toolposts. I bought one for the Myford Speed 10, and made another to for my Cowells lathe. They are very much better than the standard toolpost, and well worth having in my opinion. They are also a lot cheaper to either buy or make than QCTP s. There was a Myford sized one on ebay a few weeks ago.

The body block will be split so that it grips on the threaded upright when the bolt is tightened. I assume that the upright has a 40 tpi thread about 3/4" diameter. It appears to be a useful design variation.

Regards. Mike.

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If the threads are closely toleranced in the first place, and the tool is not doing very heavy work ... it should be quite adequate.

MichaelG.

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P.S. Apologies ... I missed the subtitle of your post

I shouldn't have needed to ask

Why? I had the impression the Norman tool post was a very rigid tool post with minimal overhang over the cross slide. On the downside the tool holders are considerably larger, but then they are far easier to machine than say an Aloris type holder. Am I missing something?

Unless I am mistaken the toolpost only takes one tool or do you replace the whole unit when a different tool is reqd?

Tony

You can have as many tool holders as you wish just like an Aloris, Dickson etc. The drawback on the Norman, the way I see it is the holders are much larger. The whole block in the top photo is the holder. The central boss of course remains on the cross slide. So if I need to replace a holder I just need to slacker the hex bolt at the aft and the holder slides off the top.

I'm thinking of building one myself, so I'm following this thread to see what's the general opinion.

Ps. Not exactly sure the one pictured above can be classified as a qctp if you have to unscrew the holder all the way up to remove it. Kind of defeats the purpose...

Edited By ChrisB on 10/08/2019 13:57:38

Edited By ChrisB on 10/08/2019 14:01:50

I think you could have a few tool blocks and also keep some notes regarding what height to set the tool blocks at if you changed the tool in the slot. I guess you could slowly build up to a set of 10-20 blocks - seems to me that there are a lot of people out there who have lots and lots of "blocks" for their particular type of QCTP.

Bill

Hi Guys,

I've built two of these for use on my Myford S7LB. One as a replacement for the originally supplied 4 way tool holder and the subsequent replacement expensive QCTP. The second one as a rear tool post replacing a parting off tool post that I made. The idea being that I can just swap tool holders between both back and front at will.

All the tool holders that I've made will take a maximum 1/2" tool and right down to a 4 mm square tool. Also the original Norman Patent tool holder used a split pinch bolt and not a slit with a bolt through the block. A split bolt gives better rigidity and better clamping. A quarter turn on an M6 clamp screw from loose to locked tight is all it takes.

I believe that the slit block was used to make the tool holder easier to make !

If It was good enough for Rolls Royce its good enough for me !

Edited By John Baron on 10/08/2019 14:22:10

But the Rolls Royce (Norman) tool post is not exactly a QCTP right? If I understand the working of that tool post, it's quick change feature is it can be slid off the top slide easily, but you need a tool post for every other tool you have, right?

I have a Myford / Drummond M type, which uses Norman tool holders

Over the years I have added to the collection and now have 10 tool holders

I think it's a great system easy to swap and change and each one is set so the tool is accurately centered when tightened in place. The only downside is you have no angular indexing, but that's not a problem for me.

Some years ago I bought a second top slide and converted it for a dickson toolpost. I bought the tool post and holders from A & R precision in coventry. They were expensive but really well made. I've used the top slide and dickson set up about 3 or 4 times in all. The whole lot is collecting dust on a shelf. I always use the norman tool holders. I must be one of the few people on here who does not like the dickson set up.

Geoff

You have a tool holder for each tool you want to use, just as you would have a tool holder for each tool using a QCTP. The post stays on the top slide, it is not removed. Also the centre hight is adjusted in exactly the same fashion as a QCTP using a screw. In the case of my Norman patent tool holder, a M6 cap screw, 39.3 thou per turn or 1 MM.

I Ebayed mine and got about half back of what they cost me. For a hobbyist not a good buy at all.

These are pictures of mine.

My rear tool post and tool block with parting blade holder.

Edited to insert pictures.

Edited By John Baron on 10/08/2019 16:24:34

Edited By John Baron on 10/08/2019 16:39:38

How does the clamping work John?

Michael Cox's collet type Norman tool post is also very interesting **LINK**

Did you bother to actually read my first post ?

Hi John,

Not just me then who dislikes the dickson setup. I guess mine will end up on e ebay in due course.

Seen those pictures before, hadn't noticed there was no split in the holder.

They/it looks well made.

You should make some with an angled tool slot. Very useful gives a little extra reach over the end of the top slide.

Geoff

Actually I did, and not just once...but looking at your photo and your description I still didn't get how the pinch bolt works without the tool holder being split at one end.

But never mind, don't worry.

Hi Chris,

Take a look at these pictures !

This picture shows the pin after it has been split into two halves and before one half has been drilled to remove the threads.

This picture shows the above being checked for clearance before drilling out the threads in one half..

Note that the split pin is machined at the same time as the hole is being bored.

It did occur to me that you may have thought that the first picture in the original post was mine !  I can assure you that it was not, although I do admit to having looked at that design and discounted it as poor.

I have all my original drawings should you want a copy. My drawings are based on the original Van Norman 1880's patent document and not on the later modified ones using a slit and a pinch bolt to clamp the tool block. It was Norman's original design that was used by Rolls Royce in their experimental workshops.

Edited By John Baron on 10/08/2019 20:19:19