Thread: My Invicta 4M arrived

In regards to the size of the tool it is mainly dependant on what you have available.
The only limitations you will have,will be your cutting.
Generally the bigger the tool the bigger the cut.
Depending on the type of work you will be doing could also influence the size of the tool.
Generally for slabbing type opperations either horizontally or vertically the bigger the tool the better.
This said the HP of the machine will delegate your cutting conditions.
If you ever get the chance to get hold of some forged HSS tools that fit you tool block grab them.

Yea, it is not the size of the tool, but how you use it that makes the most difference..

I've been thinking about the adjustable tool holder on page 4 of this thread and I'm pretty sure I made a mistake when I suggested
"As for machining it "straight" if you work out the depth of cut you want at the perimeter, set the angle so you taper from that depth on the perimeter to 0 depth at the center, that would work wouldn't it?"
I believe Bryan got it right(even if he didn't know it) in his drawing,
https://www.woodworkforums.com/attach...ived-hirth.png

The taper needs to be set to go from full depth on one side to 0 on the other side(not the middle)

Hope to get around to making an adjustable tool holder soon so I'll let you know.
Stuart

Stuart, for some reason your link is not working for me. But going by the filename, the image below on the left is the one you're referring to. In both of those drawings the lines all radiate from a single point on the central axis. And I believe that's how a Hirth coupling works. That's not to say your suggestion won't work as a toolholder of course. I'm having a little trouble visualising it to be honest. Will look forward to seeing how it turns out.

Thanks Bryan, I've fixed it.

I've added some coloured arrows. Each color is on its own plane(technically different levels of the same plane, I hope you get what I mean).
In the example on page 4. I think the point of the cutting tool went from the right blue arrow to the left blue arrow, this means it only meshes on the circumference.
I said on page 5 to go from the right blue arrow to the left red arrow "0 depth at the center", this would mean the centers of the shafts meet but the teeth can't mesh.
Now I think the cut should pass from the right blue arrow through the left green arrow to be at 0 depth on the other side of the shaft, I think this will mean that both shafts can move into each other half the depth of cut before the centers bottom.

Sorry if I'm misinterpreting your drawing and of course I could be wrong. Was outbid on a Protractor last night that I would have used to grind the tool.

Stuart

Ok, I had a different idea of zero depth. I took the origin to be zero since it's the centre of everything, however your definition of zero is correct if measuring depth of an actual cut.

So I extended my drawing to see what would happen. Turns out the valleys are opposite valleys so my drawing doesn't agree with you. However, I think that's only because it happens to have an even number of teeth. If it had an odd number, the valleys would be opposite peaks. I think in that case your geometry would work. To put it another way, if you did what you propose, it would generate an odd-numbered hirth coupling. Without either drawing or making it I can't be sure but I think it would work just fine.

PS: Your approach seems the most simple and elegant, as well as fastest. I wish I'd made my slotter swivelable so I could try it.

After some more thinking I'm pretty happy that we have it right. I might try making a rough test in the mill to test my maths and angles etc.
I just need an easy way to index it as I dont have a proper index head(yet).
Stuart

Watching with interest,
The rotary base on your vise might do for now, depending on the accuracy your after.

Dave

Great idea Dave but I'm going to need something like 40mm height difference one side of the vice to the other and I'm not sure how I'd be able to clamp it down.

I think I can make the indexer I used for the T nuts work with an adjustable angle plate. This will just be on the mill and rough to cheek I have things right as I'm pretty sure the shaper would knock this setup to pieces.

Stuart

p.s. My replacement scale should be here soon, maybe even today.

While redoing the wiring on the shaper, I took the cover off the motor and found the three wires seen in the second picture and the wiring diagram for the shaper. That's a handy place to keep it lol.
As you can see I replaced the wires.
Looking at the wiring I assume its wired in delta. Is that right?(not that it matter ATM anyway)

Stuart

Well "soon" hasn't happened, but thanks to eskimo anyone that is interested in the angles involved in the adjustable tool holder should read Machinery's Handbook 28 page 2366 Fig 4(can't say I fully understand what the first table is trying to tell me though).
Stuart

Originally Posted by Stustoys

Well "soon" hasn't happened, but thanks to eskimo anyone that is interested in the angles involved in the adjustable tool holder should read Machinery's Handbook 28 page 2366 Fig 4(can't say I fully understand what the first table is trying to tell me though).
Stuart

your up to page 2366 already?...when I get there I'll tell you what it is your trying to understand............

i think im starting to see the appeal in sharpers. they look like lots of fun.,

Originally Posted by eskimo

your up to page 2366 already?...

I may have missed a page or two, lets call it a lucky flip.
Stuart