QCTP dilema?

[Bo’sunParticipant @bosun58570]

Good morning,

I want to buy a QCTP, but which type? Piston, Dixon, Wedge, etc.

Clearly the decision is going to be a combination of function, reliability and quality. Any thoughts appreciated.

The toolpost is for a Warco WM240.

[Bo’sunParticipant @bosun58570]

[Michael GilliganParticipant @michaelgilligan61133]

With respect, Bo’sun … I see you have omitted the criterion of price from your list.

This may be of no consequence to you, or it may be decisive !!

Any of the types listed will be available in various qualities, and a good example of one type will be better than a bad example of another. … There is nothing fundamentally wrong with any of the designs; it’s the quality of manufacture that counts.

MichaelG.

[Bo’sunParticipant @bosun58570]

Thank you Michael,

Yes, price is important, but not if the sacrifice is quality and reliability (I think you know where I'm coming from).

Warco recommend their version of the Dixon type for the WM240, which, I have to admit,looks very nice. I just feel the sensible thing to do, is to look at the other options out there before taking the plunge.

I'd like to think you get what you pay for, but with an item I have limited experience with, I'm looking for some guidance.

[Ian ParkinParticipant @ianparkin39383]

Another consideration is to do with price as well

how many tool holders do you expect to end up with

i bought the Chinese piston type first (300 size)was quite happy with it but always had niggling doubts about its ridigity and repeatability

so at great expense bought a wedge type from USA ( 300 size not common over here)

and happy with that

ive had a Dixon type which came with my lathe but toolholders so expensive so sold that

and dabbled with a multifix ( the best in my opinion) but holders very expensive so sold that 

But all told now i have 50 toolholders all 300 size with various tools attachments in them.

so i would base your needs on the cost of toolholders…

Edited By Ian Parkin on 19/03/2020 09:57:11

[JohnFParticipant @johnf59703]

My three pennyworth — whilst most of the designs are probably OK personally I favour the Dickson design this along with the Multifix are as far as i am aware the oldest designs around, Dickson originating in the UK and the Multifix in Switzerland I believe.

I have been using Dickson tool posts since the 1960's and consequently favour them, however as Michael rightly points out there are many qualities of manufacture. If price is not a main criteria I would choose those made by Bison, if price is a consideration then I would buy from one of the main supplier's [RGD, Chronos,Myford etc] but whoever you choose should you need additional holders buy from the same source.

JOHN

[Former MemberParticipant @formermember32069]

[This posting has been removed]

[Brian GParticipant @briang]

I'm reasonably happy with the (Aloris copy) piston type but should we change to the wedge type we won't need to buy new toolholders as both take the same type.

One thing to consider is whether your compound slide is flat-topped or there is a spigot on which the 4-way is mounted. If there is a spigot it is easy to machine the piston type to fit over it, but for a wedge type you will need to either remove the spigot completely or do as I have done and machine it down to fit the toolpost. I managed to do this on the mill, but otherwise you would need access to another lathe or a raising block for the 4-way (which could perhaps then be re-used as a rear toolpost).

Brian G

[Bo’sunParticipant @bosun58570]

Thank you all for the quick responses,

If I take quality and stupidly expensive out of the equation, does any particular design shine through? Although it sounds like not.

To answer one of the questions above, I intend to have about 7 tool holders.

[Bryan Cedar 1Participant @bryancedar1]

Posted by Bo'sun on 19/03/2020 08:54:45:

Good morning,

I want to buy a QCTP, but which type? Piston, Dixon, Wedge, etc.

Clearly the decision is going to be a combination of function, reliability and quality. Any thoughts appreciated.

The toolpost is for a Warco WM240.

I recently bought a set of QCTP from Chronos for my Myford S7 but had to return them as the screw that is tapped into the tool holders were of different lengths. The holes were of similar depth but the tapping allowed the screws to screw down to different lengths and would not allow 8mm tools to be set to centre height. Bought a similar set from RGD which were obviously by a different maker, they were perfect. Tried to lock the Chronos threads with a thread lock but it would not take due to oil contamination which I could not remove in the tapped holes. Cannot understand why Chronos did not seem to know of this problem.

[mechman48Participant @mechman48]

… 'To answer one of the questions above, I intend to have about 7 tool holders'.

I have a WM250V-F lathe & have a ' Bison ' clone of the Dickson type qctp bought at auto jumble sale near York with 5 holders, it suits me just fine. I now have 18 tool holders each set up with particular tools & dial gauge & have used them all at some time or other, some bought from RDG at Harrogate exihib' some off eBay, some with the 'M – W' stamped on, all have averaged around£15 ea, so I would rethink '7 tool holders'… . Usual disclaimer applies.

George.

[Tony Pratt 1Participant @tonypratt1]

I have worked with most types in industry which were quality made but there are a lot of inferior products now on the hobbyist market, for that reason I sold off my Dickson clone & got a wedge type from Arc Euro, very pleased with it so far.

As an aside I am using a Multifix atm for work & I wouldn't pay the price they are going for.

Tony

[SteviegtrParticipant @steviegtr]

I got the wedge type. Very happy with it. Grips very tight against the dovetail. Was not expensive They come in a few sizes. I think 250-000 is the smallest. I bought the 2nd size up, which is the 250-111. Had to do a little work on the stud length.

Steve.

[not done it yetParticipant @notdoneityet]

I bought a piston type as a set. Bad decision as some holders were later not considered suitable for use (parting tool not horizontal – so needs resetting every time the blade is extended/retracted; ‘push’ type knurling tool – scissor type are far better for the machine). I bought the piston type because tool holders are cheaper, or easier to make.

Since then, a further two ‘not quite so quick to change’ QCTPs have come my way. They all get used, but the piston type is used most – one of them only has one small tool cutter mounted most of the time. They are all fitted to the compound slide by T-nut. A rear parting-off tool is mostly a permanent fixture – only removed when ‘in the way’- and at least a street better than the cutter fitted in an over-hanging tool holder perched on a compound slide.🙂

I anticipate actually getting round to making more piston type tool holders and moving on the other two sets.

I have considered the ‘multifix’ option and would love to have one, but just cannot really justify the price for a hobby. Cheaper ones may not be consistent and tool holders are more complex/expensive. Even a cheap one, with sufficient tool holders, would cost over half of what the (basic) machine cost me.🙂 The machine might deserve it, but it won’t happen for a while….

QCTPs are a minefield as it is, careful choice is needed and favourite is likely down to the individual. QCTPs are an added possibility for reduced cutter rigidity; multiple 4-way tool posts might even be a better option in some instances.

 

Edited By not done it yet on 19/03/2020 13:59:45

[thaiguzziParticipant @thaiguzzi]

Posted by Bo'sun on 19/03/2020 11:52:48:

Thank you all for the quick responses,

If I take quality and stupidly expensive out of the equation, does any particular design shine through? Although it sounds like not.

To answer one of the questions above, I intend to have about 7 tool holders.

I guarantee you will end up wanting more….

I started with 3 genuine, made another 10, then made another six, now 19 in total and i still want/need more…

Excluding a genuine 4 way i don't like using and a home made lantern that i do….

[Ian PParticipant @ianp]

Is there an easy explanation of what the different type of QCTP are defined as. Dickson and Multifix make sense to me (I can picture them in my mind) but with 'wedge' and 'piston' its not obvious where either of these two technologies are appliued in the QCTP

Is the piston the cylindrical pillar that the individual toolholders clamp or is the part that pulls the toolhoder against the Vee's of a Dickson. Wedge too is a loose term, does it refer to the 'cam' action of a Dickson?

Ian P

[Ian ParkinParticipant @ianparkin39383]

Ian P

the piston and wedge type are very similar the toolholders are the same

but the piston pushes the toolholders out against the dovetails

the wedge type pulls the holders in towards the block

[SamsarandaParticipant @samsaranda]

I have a Warco BV 20 lathe, no longer a current model, and I bought a Dickson type from RDG. I was happy with the quality and the price was reasonable with extra tool holders available also at very reasonable prices.
Dave W

[John BaronParticipant @johnbaron31275]

Hi Bo'sun,

FWIW, I got rid of my Dickson tool post and three holders and made my own Norman patent tool post. Much cheaper.

I also made one for the rear of the cross slide that is used to hold the parting off blade.

[oldveloParticipant @oldvelo]

Hi Bosún

A wedge and piston tool post and tool holders fabricated from mild steel are fairly easyif you have access to a mill with a dovetail cutter.

The mottley collection in my workshop have stood up to hobby machining very well for well over ten years.

Eric

[Graham StoppaniParticipant @grahamstoppani46499]

Last year I replaced my Dickson type tool holder with a wedge type one from ARC Eurotrade. Very happy with the new tool holder. My reason for changing was the old tool holder had too much play in it that allowed the tools to deflect downwards slightly while cutting. The wedge design by its nature takes up any slack when you tighten it which the Dickson type does not.

[Clive FosterParticipant @clivefoster55965]

Bottom line with QC toolposts is that they have to be well and accurately made to function properly.

Piston types were generally considered the cheap option with constructional standards to match. Hence the bad reputation. Easily made to so-so quality but the dovetails have to be really accurately matched for best performance. Which never seems to be done. Locking device is inherently in compression too which amy not be the best idea.

Wedge type positively locks against one dovetail so is more tolerant of production errors. Ultimately not as strong as Dickson, Multifix, Tripan and the other less common industrial designs. But relatively easy to produce to a respectable standard without having to chase silly tolerances. Its become the budget choice for a reason.

Dickson are quite easy to make but do require the tolerances on the pull back locking set up to be held pretty tightly. Which far too many of the affordable clones don't bother with. Hence the bad reputation in certain quarters. The actual locating guide system on a Dickson is remarkably tolerant of errors and setting up for production is relatively inexpensive too which is why its so widely cloned. Possibly the strongest post design. Not that that will worry us. Worst thing about the Dickson is that the innards seem to be a magnet for fine swarf which, if allowed to build up too much, degrades the locking and rigidity. Easily stripped for cleaning so its no great trouble to scrub them out every year.

Multifix is the high end engineered system. Pretty much has to be well made to work at all so cheap clones generally don't exist. The Create version seems to be well thought of and is not impossibly expensive so its a safe choice. Will never be my choice as stripping to clean out is hard and I can't see the point of paying for 40 tool positions, 37 of which I will probably never use. Depends how you work.

Despite its popularity with the home build folk the Norman design is flawed. The solid rod post is the weakest of the common designs and overhang relatively large. Fundamentally its designed for treadle machines where cutting forces aren't huge. But its easily made and if you don't push the cut envelope it works well.

Most painful thing about QC systems is the near universal truism that you can never have enough tool holders. Seems to be accepted that 16 to 20 "will do for now". Ideally every tool should be in a holder ready for use. But who is in a position to drop £500 or £600 plus on their new QC set.

In my view the steadily increasing use of carbide insert tooling which doesn't need easy height setting to compensate for sharpening means its time to re-consider alternatives to conventional QC posts. Especially for home builds. Slotted block posts are easily made and, if easy to change, would be an acceptable alternative to conventional QC systems.

A simple easy change design is to use a rotating centre stud cross drilled for a tommy bar arranged to engage in a castellated hollow nut on the toolpost. Once the nut is set a fraction of a turn releases the tommy bar so it can be pulled out to change the block. Needs an indexing system underneath to hold rotation alignment. Shimming HSS tools to height is much less of a pain as it can be done off the machine by direct measurement. I'd use two slot blocks arranged to index at 90° and parallel to the bed. One day I might make it just to see if it works. Having plenty of Dicksons I don't need it.

Clive

[Bob Unitt 1Participant @bobunitt1]

I have a 40 year old old Myford/Dickson QC toolholding system on my 254S. How hard would it be to make my own holders on the 254 and a VMB mill, are accurate drawings available anywhere and what's the best material to make them from (for pretty light usage) ?

Edited By Bob Unitt 1 on 20/03/2020 11:55:37

[A SmithParticipant @asmith78105]

If purchasing the Dixon type, I'd council caution, try to have a look before buying.

I recently bought two toolholders from Chronos for my Myford/Dixon system, purchased from the Nottingham factory many years ago. The new toolholders don't fit. I'll have to return them I've bought toolholders from Chronos in the past that have fitted perfectly. 5 or 6 years ago, I had to return one to RDG for the same reason, the replacement supplied was fine. I have several UK made toolholders, additional to the Dixon originals & they've all been fine.

Andy

[Tony Pratt 1Participant @tonypratt1]

Posted by Bob Unitt 1 on 20/03/2020 11:55:00:

I have a 40 year old old Myford/Dickson QC toolholding system on my 254S. How hard would it be to make my own holders on the 254 and a VMB mill, are accurate drawings available anywhere and what's the best material to make them from (for pretty light usage) ?

Edited By Bob Unitt 1 on 20/03/2020 11:55:37

You could just copy one of your 'proper' holders, hot rolled mild steel will be plenty good enough for light usage.

Tony

[Author]

Posts