Thread: Too holder screws

I want to fit longer cap screws to my tool post so I don't have to top pack certain tools.
It seems that metric square head set screws are a bit hard to come by, so now thinking socket head set screws, which are far easier to source. Any reason why that is not a good idea?

The hex holes of my cap screws always fill with swarf. I've made a few square head bolts out of ordinary hex bolts by milling their heads. Quick and easy job... Much better.

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Originally Posted by jhovel

The hex holes of my cap screws always fill with swarf. I've made a few square head bolts out of ordinary hex bolts by milling their heads. Quick and easy job... Much better.

Sent from my GOME 2017M27A using Tapatalk

Didn't think of that. Cheers.

When I use a conventional tool post I have noticed the problem that Joe refers to.

This is a rather obtuse way around the problem and its not going to help you much directly, but it shows a situation where hex cap screws on a tool posts don't matter so much.

99% of the time I use a QCTP and all the holders use hex cap screws.
I also use the diamond profile tool holders from Eccentric Engineering so I rarely remove the holder from the posts instead I remove the bits from the holder to sharpen them in the specially provided jig by Eccentric.
They also use cap screws but they are side on so don't fill with swarf.
AND
The more QCTP holders you have the less often will you have to swap bits out of their holders.
The main holder that gets tool bits swapped around is the one I mount boring bars in. But for some reason the caps screw heads on the holder don't seem to fill with swARF.

Which reminds me - I need to get some more holders.

You could turn the situation around by using permanent Loctite to fix short lengths of allen key into the head of the tool holding cap screws and make a tommy bar using a suitable socket if you have one or use another cap screw as a socket. I have not needed to try this but I think it should work and the parts are easy to replace when they get worn.
Mm.

I made a QCTP around 15 or so years ago all of the 10 toolholders have socket head bolts for clamping cutting tools and I can't recall a time where I had to clean swarfe from the socket of the bolt, I guess it is easy enough though to just slip the holder out and shake it upside down.

The compund rest is clamped also with socket head bolts, it only takes a short while before these are filled with swarfe, it is a nuisance.

So many of you have mentioned QCTPs, so I had a bit of a look at them.
I have never seen one in the flesh, so don't know if I can get one to fit my tool post, which is very different to what most common lathes have.

I found one that may lend itself to adaption, a Machifit 250-111, but not sure if I would be able to bore out the centre hole without damage to internals, and not sure if the height "E" will be what I need to retain my centre-bolt.
Any chance someone on here has one of these, and could advise the measurements "E" & "F" please, also if internals would be clear of a 16mm rebore of the centre hole for mounting?

Lathe tool post dismantled .jpgLathe QCTP dimensions.jpg

Have a look at this link.

https://metalworkforums.com/f303/t20...orman+Toolpost

I've sold my Dickson type QCTP in favour of the Norman one. Much more rigid and quite easy to make ! Primarily a turning exercise.

25-09-2018-007.JPG 25-09-2018-006.JPG
This is mine, I've since made a toolpost for the rear of the cross slide, primarily for a parting blade, but also interchangeable with the front post.

Nice work there.

Hi Phill,

If you have looked at the link, there is a drawing there for the Myford size one, adjust sizes to suit your machine. The large diameter of the post aids greatly to the rigidity but is not a critical size.

I've actually seen one of these tool holders made from a sandwich of three steel plates, each 12 mm thick, held together with screws and then machined. A lot of this type of tool holder used a slit block and a clamping screw, relying on the metal flexing enough to clamp onto the post. Whilst it can be made that way, I don't recommend it. The split collet type clamp is much superior and doesn't allow swarf to get into the slit.