homemade indexable turning tools

[mzetati]

a friend of mine brought me a few blunt inserts he had, got the idea of making the holder the 'easy' way: I'm pretty sure some more skilled hands could get to nicer results in minutes.

I a nutshell, I milled a large pocket into the back of a chinese carbide tool, drilled and tapped a hole into whatever position looked good and screwed in the most blunt carbide insert of the 'set'.
The pocket was made about 3mm larger then the insert, with the intentions of quickly filling the gap through electrical welding.
Do not want to tell You how much time later, here's the result of my efforts:

Ugly, I agree. Much worse than the out-of-focus picture shows.
But it worked well, to the point I used it to remove the scale from some cast iron I had at hand.

The picture below shows also a couple of the SH screws I turned to a 'better fit' with the insert.

The next two holders, I made more conventionally (to save some time and electric power)

The tool on the left was a perfect fit, till when I misplaced the hole for the screw. :-((

Marcello

 

[mzetati]

Made another holder for bigger inserts, then came the tiny boring bar shown at the bottom of the picture and an insert holder definitely too big for my lathe

Here’s the new holder, already reduced in size, together with a carbide flycutter I had made years ago. That flycutter never worked too well, but it was the only cutter I had suitable for the job of thinning that shanks.

Days later, that same scraps bin revealed some more turning jewels

And a coupla indexable mills, here’s one at work:

(You will notice the chipped edge on the mill insert)
More tools, a RH one for bigger inserts and a parting holder. Well, most of it as the insert broke and the tool itself hit the workpiece. They’re too huge to fit my QTCP (had to remove about 8mm from the bottom face to have them set on the lathe centerline).
Had the idea of making them QCTP-compliant by bolting a dovetail right on their shanks

When I had to bring the dovetails to the wanted thickness, I set the QCTP vertical into the vice.
It worked.

Then came the drilling of three holes into each dovetail and shank. (Gosh! They’re tough.)
Bad news, as I had suspected while drilling, came when I tried tapping them holes: no way, though I had made them well oversized. I managed to punch (most of) that tap outta that shank, anyway.
Now it is either a bolts and nuts job (but aint much happy with the idea) or having them dovetails soldered in place (by some skilled hands).

Marcello

 

[Niels Abildgaard]

Hello Marcello

Have been there myself but found another way.
It is nearly as fast to change as a QCTP and miles cheaper and more rigid.

 

[mzetati]

Hello Niels,

that holder of Yours surely beats mine in rigidity but I'm sure I win when it comes to repeated tool swaps: have a look at my rack.
(The time spent into making them holders does not count, of course).

[The rack base was a CD holder. The backs of the slots were filled with plastic foam offcuts to prevent the tools from hiding into their holes anytime I accidentally hit them].

As for costs, we're even: my QCTP and holders being homemade from polished scraps. (Again, electric power and costs of the cutters* are to be counted into the fun, not the item).

Please, disregard that golf ball on the QCTP lock: it's still there, though I've made a ball turning attachment to replace it with something more appropriate, some years ago.
Just never got around putting it into work.

--

On more serious terms, now You've shown me those pictures I recall having seen Your holder before, maybe on this same board. Thank You for reminding me of that, the idea is fairly good: especially when applied to that large parting/grooving tool I've shown above (inserts being 8mm wide. I suspect chatter and stoppages will be in order, when I will try to use them).

I will have a look about how I might fit it (over or without the compound) next time I'll go to the shop.
Thank You very much, again.

Marcello




*) even the 4jaws was purchased on that occasion: at that time, I did not know I could offset the workpiece just by shimming into the 3jaws.