Ideas for tangential cutter tool holder?
I'm looking at putting together a tangential tool holder to suit Norman Patent style QCTP systems, primarily this one:
Here's the design I've come up with:
A few disadvantages I can see right from the start: The front face of the holder has a 12 degree angle with respect to the back face. The slot for the holder has a similar 12 degree angle, but should be much easier to accomplish, as it's just a 0.25 inch slot.
Here's what I'm curious about: I'm looking at securing the tool in the slot with a large conical washer for a flat face M4 socket head cap screw. The slot will be ever so slightly less than the width of the tool. I don't think it will be enough, but I'm not sure.
I'm wondering if anyone has a better idea for accomplishing this.
Last edited by burdickjp; 11-23-2014 at 10:47 PM.
It looks like the washer will be in the way of the stock being turned. You could bandsaw a slot along the inside edge of the lathe bit slot and use a flathead screw coming in from the side opposite the slot in the drawing to clamp it in.
I think if I mirror the whole thing to put the washer on the face closest to the head stock instead of its current face that may cure that. I can also run a thinner washer or recess it or something like that.
Originally Posted by Toolguy
I've made a couple of these tangential toolholders now. My favorite design looks like this:
This design allows for turning and facing without changing the set-up of the holder. The tool-bit is held very firmly--never had one slip!
Here's a couple pics of the toolholder:
Here's another one that uses a round bit for radii between facing and turning or taper and face, etc.
Maybe you could adapt this to your tool post?
I had been looking at the ones that grip that way and scratching my head as to how they get in there to cut it that way, and as I was looking at your pictures it dawned on me.
It'd probably still be useful if you could discuss how you went about it.
It can be done in essentially 3 setups:
1) Drill the hole for the back corner of the toolbit, and the "flex" hole for clamping
2) Machine the slot for the tool-bit. Use a slitting saw to remove the metal for one corner, a small end-mill to remove the metal from the other.
3) Remove metal to shape the front and side of tool-holder, cut slit for clamping, drill and tap for clamp screws.
Last edited by Jim2; 11-24-2014 at 02:59 PM.
Reason: added coordinate axes to drawings
That is fantastically helpful. Thank you VERY much.
I love the tangentials! Always happy to spread the good news.
Here's where I'm at thus far with a clamping-style tool holder. I'm thinking one or the other sides needs a slot so that clamping the tool doesn't work against clamping to the post.
I think it'd be easy to add another tool to the other corners of the holder. Either 1/8 inch or round or whatever.
I'm trying to decide if it'd be advantageous to make the thickness of the holder such that I don't need to adjust height by moving the holder vertically on the post, since the tool can move vertically in the holder.
Last edited by burdickjp; 11-27-2014 at 11:24 PM.
Here I've made the clamping mechanism different and added a round holder.
I think when I go to make something I'll start with round since it will be much easier to manufacture.
The rest of it honestly looks much more complicated than I want to attempt making. Way too many set ups and processes.