Thread: Really small QCTP's?

This is the current tool post on the ML10.
P2080001.JPG
It is usable but a QCTP would be nicer. Trouble is, there is only 13mm between the axis of the lathe and the top of the compound. I have some 5/16" HSS blanks but boring bar plus clamp block is around 1/2". I thought I had saved a set of drawings for a DIY multifix tool post that someone posted, but my filing system has defeated me on this one.

So, has any one got a copy of those drawings (or can find the link); alternately, does anyone know of a really compact design of tool post (either commercial or available for metal working types) that may form the basis of something or even just bolt straight on?

Michael

Hi Michael, i think that i would contemplate a packer for the head and tailstock then deal with the toolpost.
cheers shed

If you need more headroom for tooling could you make your qctp hang over the end of the compound effectively giving you unlimited headroom, on a big lathe that would lose you rigidity but on a lil guy like that i dont think it would change much.

This one requires ⅝" from compound to lathe centre. Could you mill 3mm off the top of the compound?

https://littlemachineshop.com/produc...ProductID=3112

Hi Michael,

Thr original one on my S7LB was like that, I then bought the square four way one which, although I made a QCTP to take 1/2" tool bits I don't use very often. I've seen an ML10 where the top slide has been removed and replaced by a post with a commercial QCTP but it didn't have the top slide fitted. I have a drawing somewhere that gives details for making one but it still needs a post to put it on.

Some people swear by alternative toolposts that replace the top slide completely. Especially on smaller lathes it’s said to increase the rigidity enormously and at the end of the day we don’t actually use the compound all that much.

1/2” is super-weeny and I think that’s what I’d be looking at in this case. It will give to much more room and allow you to use a conventional AXA toolpost, increase rigidity, and would be easy to pop off for the times you need a compound.

I really must get around to making one for my lathe, as it can use all the rigidity it can get!

I was looking at solid tool-posts just a couple of days ago. It's very tempting. Here's one (elaborate) solution: https://www.youtube.com/watch?v=pG3YSfgyJPI

Agree. I was thinking along similar lines myself - taking 3mm off the top of the compound reduces it to a thickness that I regard as marginal, so don't really want to go there.
It leaves the choice then to either hanging tools off the edge of the compound or replacing it entirely. The ML10 does have a T slotted cross slide, so I don't even have to use the compound mount if I don't want to (and as it is small, I don't...)

Michael

One thing I noticed with the Hercus is not to have too much tool overhang, especially when parting. A CVA these are not! By bringing the thrust line back between the ways as much as possible the rigidity is improved

Michael check out LPR Tools he does Myford stuff

https://www.lprtoolmakers.com.au/sea...ection=product

Michael,

I tried to send that file to you but Telstra just bounced it back to me. Claimed to have been rejected by a remote file server.

Ken

Ken kindly sent through a set of plans for a multifix style holder - unfortunately it is too big as drawn so would need to be scaled down. Not a big problem but still an issue so I'll have to look at that. I have decided to go with the suggestions made above to look at removing the compound and making up a custom mount - I may have to revert to the standard one for thread cutting but we will see. A multifix holder would be a good solution for that so it may have to be a longer term project.

Michael

I think I'd look at making it capable of pivoting on an axis and just manually set up the angle as required. It would mean more basic thread cutting (ie plunge only and not just resetting to zero), but unless you were planning to cut a lot of threads I don't see it as a show-stopper. Just write down what the compound setting is each cut to keep track of it

Hi Michael, just a thought, maybe you could make up several little tool holders similar to my classy drawing below.

Adjust the tool height for the various tools with shims, hold the hss and shims in place with a grub screw, you could likely make a few that would locate the end and side of the compound to get repeatability when swaping tools.

On small lathes (and some large) I often would firm up the centre gib screw, this can make a big difference to the rigidity.

Hi Michael,

Don't know if this is any help, its a drawing and two pictures of the QCTP I mentioned earlier,

Drawing-1.JPG

This could easily be scaled to suit. All the holes are based on a circle. Non of the dimensions are critical so it could be modified as needed. I admit that I made a number of mistakes when I made mine, silly ones such as getting the tool holders wrong by making them too wide.

QCTP-a07.jpg QCTP-02.jpg

These are a couple of WIP pictures. As can be seen the tool holder sticks out way too far. If I make some more tool holders I would make them much narrower. I made this to handle 1/2" inch tools, only because I found a box full of new HSS blanks.

HTH.