Myford Dixon-type toolholders: different dimensions?

[iconParticipant @icon]

I thought I’d treat myself to a couple of spare toolholders for my QC toolpost – I have seven holders of varying provenance, picked up at random shows, and they all fit fine. I confidently bought a couple from RDG on Amazon (https://www.amazon.co.uk/dp/B0C8NNK4YR) and they don’t quite fit – they’re a fraction too wide across the angled ‘shoulders’ so they won’t drop onto the clamp; they seem to be identical in every other dimension. Are there two types of almost identical toolpost, and I have the wrong one? There’s no markings on mine, but I suspect I bought it from the Myford stand at a show, decades ago. Might be wrong!

[Tony Pratt 1Participant @tonypratt1]

I’m afraid whether or not your new toolholders fit the tool post is a matter of pot luck, and no there are not two almost identical designs of tool posts. The original UK design has been copied by all and sundry but the subtlety of dimensional importance has not been followed in manufacture.

Tony

[Neil LickfoldParticipant @neillickfold44316]

For some holders, it is the thickness of the area where the clamp fits into the woodruf slot.

Others , it is the ground Vee profile is too thick or too far from the woodruf slot.

Mine, I got a carbide single point milling insert cutter, will cut Oring grooves etc on a lathe, and recut the slot area that the clamp fits into. On one of the holders, the slot was not only too thick by about 0.8mm, it was too narrow by more than 1mm .

I have the Original Dickson blocks , and the holders have a W stamped on them. I did buy a copy one from a supply place in Auckland, and all it’s holders also interchange superbly.

It appears to me, that unless you get them from who ever originally made them, the copy sets are a gamble as to if they will fit.  Getting a generic block, and it’s holders from the same supplier, they should all fit.

It is very frustrating when they are not made correctly.

[MacolmParticipant @macolm]

The interface is problematic for volume manufacture, and I suspect for best fit will need a second operation shave off one or other of the V faces, either in a jig or after checking the sizing. Clearly the original maker allowed for this, so it makes buying low cost copies a bit of a lottery.

[noel shelleyParticipant @noelshelley55608]

The Myford units with a W stamped on were made by a fellow down in the west country for Myford. I bought some tooling off him, an interesting fellow. Noel.

[jaCK HobsonParticipant @jackhobson50760]

The ones I get are always relatively soft metal and can be fettled with a file to fit. Might take a little while.

[EmgeeParticipant @emgee]

If you have a milling machine it’s not so difficult to make your own, I made some from EN8 for my Emco 5 cnc lathe and have not found any problem with variable tool references when changing tools within a program run, link below to the Youtube video for those interested, mostly at actual speed so quite a long video but it’s simple to skip over.

https://youtu.be/KNo82KCiGdo?si=Fgqtp09ScPrKRRE1

 

Emgee

[SillyOldDufferModerator @sillyoldduffer]

Had to smile a wry smile because I was recently assured by mgnbuk, who is keen on QCTPs,  that:

Most of the sizing related QCTP questions that pop up on here could be easily resolved by a bit of reading of the QCTP system spec sheets & a couple of measurements from the lathe concerned – it isn’t rocket science ! (His post #764721.)

I hope Nigel (mgnbuk) will be along to help icon soon.

A few have suggested that the reason holders don’t fit is due to poor copying or quality management.  They may be right, especially at the too cheap end of the market.   Other reasons possible:

QCTP tool-posts and holders are not made to a standard, there isn’t one, so there’s no particular reason why a Dickson-style holder should fit a QCTP made by someone other than Dickson.   It might, but no guarantee.

Holders are certainly made to fit a particular holder, and these could be deliberately different from others for commercial reasons:

• Proprietary lock-in, whereby purchasers are nudged into placing repeat orders with the original supplier.
• As a way of avoiding Patent restrictions or license fees.   Whoever owns the original design doesn’t have a clear claim because the alternative holder and QCTP aren’t interchangeable with the original.  No money changes hands because the two systems are incompatible.   Hint: often possible for owners to machine alternative holders to fit, and them being slightly too big suggests the option may be built-in ‘accidentally done a purpose‘.

None of these games are new!  Buyer beware.   The best answer seems to be to buy a large set of holders with the QCTP at the same time.  Trouble is much more likely when folk start by buying a few holders and then add more several years later.  Another is to buy from a seller like Myford, who maintain consistency over time.   But their holders are on the pricey side, making it oh so tempting to look for cheaper on the web…

Dave

[JasonBModerator @jasonb]

Dave, Mgnbuk was talking of the size of toolpost and holder heights not the size compatability of originals and copies.

Oh and Dickson never made them, they were made by Wessex Weston Engineering hence the “W” mentioned above.

[noel shelley]

On noel shelley Said:

The Myford units with a W stamped on were made by a fellow down in the west country for Myford. I bought some tooling off him, an interesting fellow. Noel.

I have a couple of these! I might just try RDG’s ‘proper’ Myford ones – hopefully they’ll fit.

[SillyOldDuffer]

On SillyOldDuffer Said:

[…] Another is to buy from a seller like Myford, who maintain consistency over time.   But their holders are on the pricey side, making it oh so tempting to look for cheaper on the web…

Dave

This is a delicate matter, and I will not be surprised if my post is deleted by the Moderators … but here goes:

’cheaper on the web’ was in this case a purchase from RDG

I believe it is common knowledge [it certainly should be] that although RDG and Myford are separate Companies, some individuals are involved in both.

I have no idea what, if any, inter-company trading occurs; but it is tempting to think that some items are ‘made’ by RDG and the best of those are selected to become Myford items. … I hasten to add that there would be nothing inappropriate or unreasonable in this !

MichaelG.

[JasonBModerator @jasonb]

Two different tool posts Michael so not a case of picking the ones that come in on spec and badging as Myford.

The Myford one would be about double the price of the RDG once you figure in the additional holders as the Myford only comes with two compared to the four with the RDG.

Also if you look closely at the tool holders you can see that they are machined differently on the mounting faces so off a different production line.

[Michael GilliganParticipant @michaelgilligan61133]

Apologies for my misunderstanding, Jason.

… I regret the subtlety of the Amazon listing must be lost on me 🙁

MichaelG.

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[John PurdyParticipant @johnpurdy78347]

About a year ago I bought 3 new tool holders for my original Myford tool post from the current Myford, 2 standard and one extended nose. While they all fit the tool post with no problem, the two standard ones won’t allow the use of a 3/8″ tool bit. They can’t be lowered enough so the tip is on or below centre line. The distance from the bottom of the slot to the bottom of the tool holder is a full .050″ larger than the original Dickson ones, .275″ vice .225″. The extended nose one is OK, .225″. I believe it is made by a different supplier. I though about putting them in the mill and milling off the excess .050″ but they are dead hard, and I don’t know anyone with a surface grinder.

John

[Michael Gilligan]

On Michael Gilligan Said:

Apologies for my misunderstanding, Jason.

… I regret the subtlety of the Amazon listing must be lost on me 🙁

MichaelG.

.

You image is also lost to me and the members.

A close look at the offerings on the Myford website and the RDG Website will show the differences but I’ll take a photo tomorrow which will be clearer and make it obvious that the “Dickson style” are not made with the same process as the originals or those on the Myford site.

I have been able to modify one batch (Chronos) with a belt sander and another (RDG) with a Woodruff cutter but it did render the cutter not much use for anything else.

[JasonB]

On JasonB Said:

image is also lost to me and the members.

Like so many things ‘round here …that’s disappointing

It was simply a screenshot of the Amazon page linked by the OP, with the following words ringed in Red, and an arrow pointing to them:

2 SPARE HOLDERS FOR MYFORD QUICK CHANGE BLOCK

MichaelG.

 

[JasonBModerator @jasonb]

outweighed 2:1 by “Myford size” and “Dixon style” Not even DICKSON

[Dave HalfordParticipant @davehalford22513]

There was also a time when ‘Myford’ brand tool posts were made by A&R Precision in Coventry. They subsequently lost the contract to someone else, whilst beginning to sell them under the A&R brand on ebay.

So there are at least 3 different suppliers of genuine Myford tool posts.

[Michael GilliganParticipant @michaelgilligan61133]

I await clarification in due course

Can’t personally get excited about any of this nonsense

I still have a boxed set purchased from Beeston, as-yet unused because of domestic and health problems.

[ all the parts fit together as they should ]

There are more important things in life.

MichaelG.

[Michael GilliganParticipant @michaelgilligan61133]

For the avoidance of doubt:

DIXON = https://youtu.be/K-U7yl7tvtU?feature=shared

MichaelG.

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[mgnbukParticipant @mgnbuk]

I hope Nigel (mgnbuk) will be along to help icon soon.

Naughty Dave !

As Jason has already pointed out, you are taking a quote about one aspect of QCTP selection (measuring up the lathe to determine most suitable size of toolpost) and using it in another, completely different, aspect (inter-operability of components from different manufactures). Tut Tut !

I guess I must have been lucky with the latter – toolholders purchased from RDG & Chronos at various times fit both the original Myford supplied (W marked – bought from the Beeston Spares Counter) toolpost and an RDG purchased rear mounted QC toolpost just as well as those supplied with the Myford set. So it would appear that any tolerance or dimension differences there may be between my examples don’t interfere with normal operation. Same goes for the Indian made Ebay purchased larger set I bought for the Warco GH600 – not all the holders came from the same maker by the looks of them (many detail differences from those supplied with the basic set), but they all fit and function just fine.

Nigel B.

[mgnbuk]

On mgnbuk Said:

I hope Nigel (mgnbuk) will be along to help icon soon.

Naughty Dave !

As Jason has already pointed out, you are taking a quote about one aspect of QCTP selection (measuring up the lathe to determine most suitable size of toolpost) and using it in another, completely different, aspect (inter-operability of components from different manufactures). Tut Tut !

…

Nigel B.

It’s true Nigel, but you did the same to me in the other thread.  I posted a list of potential QCTP misfit problems which you mostly ignored, instead concentrating on one of them as if that solved all problems.  For example, after I suggested buying several holders with a new QCTP  tool post, the advantage being the ability to quick-change most of the cutters, you dismissed that by saying you could manage with only two.   Duh…

Has enthusiasm for QCTPs led you to believe they are beyond criticism?  I’d rather beginners where told of the potential pitfalls, thereby enabling them to avoid trouble after purchase, and when buying holders later.

Cheers,

Dave

[JasonBModerator @jasonb]

As this thread has come up again I took the photo I mentioned several posts back.

On the right is an original “W” marked tool holder, on the left two differently sourced similar style holders.

The green shows the obvious differences which would seem to indicate that each has been made on a different production line in a different factory so unlikely that cheaper ones are just rejects that do not meet the standards of the best ones which get sold at a premium with a premium name on them.

The red indicates where I have found the problem of fit is. The original is quite a bit thinner. Some of the similar style I have been able to thin the surface where the two are touching on a belt sander as that surface touched the post before the clamp was tight. Others have needed a woodruff cutter to get into the back as the piston would not extend out enough to allow them to fit. But all are usable and as the last lot cost me £50 for 4 that is a lot better than Bison or similar prices.

The original is also a couple of MM shorter which does give a wider adjustment range so touching on Nigel’s comments don’t make use of the established suppliers who publish the tool post sizes and then go and buy “the same” cheap one from elsewhere as it is unlikely to be the same. Also if shoping for additional holders visit the supplier or a show and take your post with you to test the fit.

It would also seem that Pratt Bernerd have the “Dickson” name and use it on their version, although they don’t do the small myford size the prices of what they do make are considerable.

If you are of a sensitive nature about your 4-way tool post don’t read this

[Grindstone CowboyParticipant @grindstonecowboy]

I have one holder for my Boxford Dickson toolpost that is thicker than the others in the area Jason highlighted. However, it fits the toolpost OK, and I only noticed when I 3D-printed some holders, and it wouldn’t fit on them. No idea who the supplier was as it came with the lathe.

Rob

[JasonB]

On JasonB Said:

[…] obvious differences which would seem to indicate that each has been made on a different production line in a different factory so unlikely that cheaper ones are just rejects that do not meet the standards of the best ones which get sold at a premium with a premium name on them. […]

Just curious …Do you have an example of what Myford is currently selling, to compare with what RDG is selling ‘for Myford’ ?

… That is the question

MichaelG.

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