Damaged Screws & QCTP help!!!

Let me know the two shown

Edited By JasonB on 30/07/2023 20:48:45

Jason:

Thanks for those Margret, Both the QCTP you have and the 111 would work with larger tooling but the 000 may not suit the smaller sizes. To check exactly what works could you put something pointe din the lathe chuck or tailstock and take the measurement from that to the top surface of the top slide as below

Also if you could measure the diameter of the threaded portion of your toolpost stud that would help deciding what's the best way to modify that. I suspect it's an M8 thread so should be 8mm or a bit under.

As jason says, the thread on the original toolpost "bolt" is probably M8, while the new stud for the QCTP may be M10.

IF long enough the "bolt", having a 10 mm shank, wsould be useable with a new washer, Top Hat or conical, with the QCTP.

The damaged csk screws can be replaced by ordinary csk Allen screws. No need to anything different.

Howard

Hello chaps,

sorry for my late responses but I am at work.

I am awaiting responses from arceuro and Amadeal.

Jason - putting the tool in and offering up to a workpiece looks fine - although I did have to adjust the tool holder up a little (not sure if this is normal practice as i have nothing to compare against) - but a standard tool of the size I generally use does reach the work piece ok. See pic. I will try the stud later when home tonight but it looks likely that the stud will work or worst case, I need a new stud. The threads on the original stud look a bit worn don’t they?

i’ll send dimensions of the stud later when home and reply to all the pm’s.

thanks all

M

Edited By JasonB on 31/07/2023 11:26:56

Thanks Margret.

Looking at the first photo the tool does not look like it is not yet lined up with the ctr of what you have in the chuck so could do with going up maybe another 2mm. This will put you right at the limit for that height of tool (10mm? ) and anything smaller won't really come upto ctr height without being packed up. So I would be more likely to opt for the 111 toolpost with standard holders so smaller tooling can be used. (hope the bottom ring is screwed on in that photo)

The other advantage of the 111 is the hole in the middle of the toolpost is 14mm which would be better to allow the existing stud to be retained and a shouldered nut made.

Hello chaps,

sorry for my late responses but I am at work.

I am awaiting responses from arceuro and Amadeal.

Jason - putting the tool in and offering up to a workpiece looks fine - although I did have to adjust the tool holder up a little (not sure if this is normal practice as i have nothing to compare against) - but a standard tool of the size I generally use does reach the work piece ok. See pics. Although I am concerned how far I have had to adjust it. There doesn’t seem to be much thread left on the adjuster- is this normal?

I will try the stud later when home tonight but it looks likely that the stud will work or worst case, I need a new stud. The threads on the original stud look a bit worn don’t they?

i’ll send dimensions of the stud later when home and reply to all the pm’s.

thanks all

M

Hi Jason, just read your latest response during a break (lol). Yes I think you may be right, it does seem quite near the extremity of it's adjustment - I think the 111 might be a better option. See pics below, they show clearly how near it is to the limit of adjustment.

Do you agree?

How I would make a shouldered nut though, I have no idea!

I have just asked my brother to measure the distance from the top of the top slide to the centre of the workpiece/chuck - it is 20mm.

Does that help in anyway? Looking at arceuro's spec, I can't make head nor tail of which QCTP is the correct one for this!

That sounds a bit low to me, from the photos I would put it closer to 25-28mm maybe check again when you are home.

The tool opening in a holder is 13mm so your tool looks to be about 10mm square. Max height of the bottom of the holder is 17mm but your adjuster is a couple of mm from max so lets say 15mm. so add the 15mm and 10mm and the edge of your tool is 25mm from topslide surface.

As for the nut well it only needs to be hexagonal if you want an extra spanner to loose. Simpler to go with something like you have that is cylindrical with either a fixed tommybar or just a hole for one. You could use the washer that comes with the toolpost then it is just a case of turning one end of some say 25mm bar down until it fits inside the toolpost and threading that end to suit the stud assume M8. Last thing is a hole for the tommy bar.

Not far off what I use on mine, the hole is drilled so I can use the chuck key to tighten the "nut"

the larger 14mm hole in the 111 toolpost gives a decent amount of metal around the M8 thread that you would not get if it had to fit the 10mm hole of the 000 size

Hi Jason,

Thanks, I'll check the measurement when I get home. That is a nice QCTP you have on your machine, where is that from please? Would it fit my machine do you think?

Many thanks

Margaret

Hi everyone,

OK, I have come to a decision. It's been a day of lots of conversations and to-ing and fro-ing. I have been overwhelmed by the helpfulness of Ian at Arceurotrade but the long and short is, I am reverting back to my original 4-post tool holder.

The QCTP has defeated me and being honest, my abilities are not sufficient enough to make a stud (or even Jason's suggestion of a shouldered nut). Kind offers from you gentlemen have humbled me, but realistically, I don't use the lathe enough yet to warrant going to all the effort to get one made.

Thank you all for your support and effort. It's been quite a weekend of broken screws, drilling, tapping and generally messing about with something which I had hoped would be an easy conversion.

But that's it, in a nutshell. It's not the end of the world. It's a learning curve and I may revisit this in the future if I find I am using the lathe more and more.

Again, thank you all.

M

Although the decision has been made - like any good government does - I may do a U-turn lol. I ‘may’ swap the 000 for a 111 anyway and keep it for a rainy day when I have more experience. Although it will present the same issue with the rogue stud, it will at least be more suitable for smaller tools and not need the extreme adjustment position them as the 000 need.

Jason - you were right about the measurement. Somebody (who shall remain nameless) didn’t do it correctly - it’s 22mm. Does that help in anyway?

Ps: it could be more than 22mm Jason but my topslide is not bolted together at the moment while I await those new screws.

That is an original Dickson toolpost that is mostly equipped with additional holders purchased from Chronos of no doubt of far eastern manufacture, most fitted straight away but a few needed a tweak or two. I was already on my previous lathe when I bought that so as I had a lot of holders I made it fit my Current Warco and added even more holders. Interestingly it is a bit short for this larger lathe so It sits on a square of 1/4" steel to raise it up which would be an option for you but I think the 111 would be better due to the ease of making the nut shown and by retaining the original stud you can easily use the old 4-way post for large tooling, I do that when I want to use large boring bars that won't fit the QCTP.

If 22mm plus is correct then a 111 will allow you to use upto 10mm sq tooling with the standard holders or 12mm with the slim bottomed ones. You will also be able to get smaller tooling such as 3 or 4mm square HSS upto ctr height which is handy for making small form tools as the small section makes it quick and easy to grind.

When you feel ready I'm sure you will get 20 different suggestions on how to make a nut like I show.

Thanks Jason - great info.

Should I decide to have a crack at the stud, what material would you suggest? Mild steel? Did we say it was an M10 thread on the QCTP top? I can’t find the post with it on!

The nut would probably be the easier of the two to make,just needs to be tapped M8 (to be confirmed) for your existing stud and could just be mild steel.

As could a new stud though the serrated part would be the hardest for you to make and get a good fit so that the stud does not rotate. The 000 uses an M10 thread the 111 a fine 1.5mm pitch M14 thread as standard.

I do fancy a crack at the nut.

Would the stud need the serrated part - could it not just be machined to a tight fit?

Just watched a YouTube video where a chap had a problem

mounting a 111 due to the spindle being incorrect - so he drilled the supplied internal mounting bolt of the 111 and tapped it - then fitted it over his spindle. Seemed to work

well.

Yes that is an option with the larger 14mm dia of the 111 QCTP, the one from the 10mm would probably be a bit weak by the time M8 thrad had been cut into it.

A tight fit without serrations may work, possibly with some Loctite. A lot of other designs have a tight fit AND a small pin to ensure the stud does not rotate.