Tangential tool holder for the mini lathe

[Galileu]

Hi,

These days many people are talking about tangential tool holders and all those who have tried them seem extremely pleased with the results. TTH come in many forms and, after reading a lot about it, I decided to give it a try, with the meagre resources that I have available, that is, milling was no option.
My 7x12 Einhell has a very short distance from the top of compound to centre line, not really enough to hold a tool bit tangentially, so the tool holder had to be designed to drop below the compound top. I started with 10mm 1018 steel plate and cut the basic shape with the band saw.

Then I chanfered the top at 15 degrees in the table grinder, both to reduce height and to provide a flat surface for a 15 degree hole. Next a 6mm hole was drilled at 15 degree and two pilot holes were also drilled for the tightening screws. The shank was then bent at 45 degrees to approximate the angle of attack.

The holder body was then slit open, the 6mm half-hole was shaped with a square file, the pilot holes were tapped M3 on the main body and enlarged to 3.5mm on the cover plate and several clearance surfaces were ground. The first trial cut is shown in the next to last photo; I've since made several cuts and I'm very pleased with the results.

I had previously made an experiment with another holder, without 45 degree shank angle, with the peculiarity that it 3mm uses concrete nails for tool bits; as you can see it also works pretty well. In both cases the tool bits were sharpened in their holders, with the table grinder, using my angle setting jig.

José

 

[FarFar]

Hello Jose

I am fan of tangential holders myself and will congratulate on the design using no mill.
It migth even be possible to avoid the square filing operation and use a presss as they have on every auto repair shop.
Drill hole a little undersize ,force a little open,put in a toolbit and squeze violently.A hammer will probably also do.
What on earth are the 3 mm concrete nails You mention?
Picture and short material describtion please?
It is very seldom that I cut swarf more than 3 mm deep.

Regards

Niels

 

[Galileu]

Hello Jose


What on earth are the 3 mm concrete nails You mention?


Niels

You know... The sort of nails used for hanging pictures on walls! They are very hard but you can grind a 30 degree surface at the end and you're in business.

Regards,
José

 

[Hawkeye]

Nicely done, Jose. Until you use one, it's hard to understand how well they work.

You'll have to show us the experimental one now. The concrete nail is a great idea. Really hard steel. That would be a quick one to throw together in a hurry.