Hi I fitted one of these to my ML4 which has a 7/16 dia toolpost stud, all that was necessary was to bore the diameter of the centre of the toolpost to fit the slightly large stud. It is hard, but chinese hard! so even the weedy ML4 coped with a carbide tipped boring bar.This only require the removal of about 20 thou and seems to have had no effect on the improved rigidity and general ease of use over the original jack stud, shims and relying only on the stiffness of the stud to resist cutting forces.

I hope this is useful to you

regards Paul

The Dixon type tool posts are good IF made to a high standard, the imports are not so I would go for a wedge type.

Tony

Chris M,

I have purchased dozens of items from Arc over the years and all orders found to be satisfactory and arrive quickly, so no worries there. Most of the ME/MEW advertisers have been found to be quick and supply reliable goods

John

Much better to ask yourself this question: 'Why exactly do I need a QCTP in my workshop, doing the sort of work I do'

A very bad answer would be: 'Don't know, but other people are pleased with them.'

A good answer would be: 'I understand the pros and cons of a QCTP and know the type of work I do will be facilitated by fitting one because [list of reasons]. ' There will be a clear idea of how many holders are needed: 2,4,6,8,10 or more. Not knowing how many holders are needed suggests a rethink is in order!

Different rules apply in 'for fun' rather than 'for production' workshops. If the workshop is for fun (which includes self-education), it's entirely respectable to tool-up whimsically and to accessorize however the fancy takes you. The main objection is cost, and it's not appropriate to learners on a tight budget!

While both approaches to Model Engineering are valid, I suggest it pays to think about which class one is in before rushing to spend money. If cash is short, it's definitely better to approach purchasing carefully which requires experience and understanding to be developed first.

That said, buying a QCTP (with sufficient holders), won't be a disaster. It's just that the money could have been spent on something more useful like a DRO. I'd say a 4-jaw chuck, micrometer, dial indicator and stand, digital caliper, and grinder are all far more important than a QCTP. The most useful tool in my workshop is a bandsaw: because sawing metal by hand is a boring, sweaty time-waster. My saw saves more time than a QCTP ever would!

For what it's worth, I decided not to fit a QCTP to my lathe immediately because – although it seemed a good idea – I didn't know if it would help me do what I expected to do. 8 years later I'm still happily using a 4-way tool-post, and it's crystal clear a QCTP is unnecessary in my workshop. My experience doesn't damn all QCTPs to perdition though, because many others benefit from them: the value of a QCTP depends on the type of work done by the owner. Only Chris can explain that!

Dave

Edited By SillyOldDuffer on 26/08/2022 10:37:29

Having owned a lathe for about 40 years, I soon graduated from the Myford clamp arrangement, to a four way toolpost, and then made a rear one for the ML7. On the larger successor, stayed with the four way supplied, and then made a four way rear toolpost.

This allows me to have six tools available. Normally, Carbide rougher, Carbide boring bar, Tangential turning tool, in the front post; Front Chamfer, Parting Tool, Back Chamfer, in the rear post.

The rear post was made specifically to take the rather large Parting Tool that I had been given when I bought the ML7. The blade still has a lot of life left in it!.

If any other tool, (usually knurling, or radius turning ) one of the "normal" tools has to come out, temporarily, most often the Boring Bar..

But I have no need to save a few seconds, on each operation, since piece work is not part of my pension.

QCTP came about to save time in industry where time is money.

They have the advantage of keeping a tool, once set, at centre height

From what I read, it seems that a lot of QCTP s require some modification to either the QCTP or to the Cross Slide to enable their fitment.

Although I could afford them, I lack the space to store about ten holders, and survived for a LONG time, quite happily with my set up.

But each to their own. If that's what you want, go ahead and buy one, but make sure that it will fit, or can adapted easily be modified to fit to your lathe..

Your lathe already has a four way post, so, as beginner, there must be more important things to learn to use than another toolpost..

Beware of having all the gear, but no idea of how to use it! I have fallen into the trap, thankfully not often, of buying something because it seemed a good idea at the time. (Tailstock capstan, and Tilting Table fall into that category! )

NOTE. Shims to adjust tool height can be made by cutting up tins, such as Sardine or Biscuit tins. They are usually 0.010" thick material. )

Howard

Edited By Howard Lewis on 26/08/2022 11:27:45

In my book good surface finishes are produced by having a correctly ground tool set at centre height, and with a fine feed rate.

These are things that have to learned at the bottom of the learning curve.

They were for me, in my first few weeks as an Apprentice!

I was fortunate in that EVERYONE, no matter what Grade of Apprenticeship you were on, you spent the first year in the Training School, to learn the basics..

Howard

My QCTP set up can take very big cuts if need be. However the set up is not as rigid as the 4 way. Taking deep cuts with both set ups, shows this quite clearly.

Andrew.

Chris, If you talk to Arc,I think you will find that they do not reccomend enlarging the bore of the oo qctp

they supply. regards, Lynne

Isn't that why ARC supply the new stud, so you don't have to make one. I think John Stevenson worked out the sizes required so it should be upto the job.

My friend has the Myford QCTP on his ML7. The best part, is that we can share holders or tools of need be.