Tangential threading tool?

burdickjp

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I was putting together a design for a tangential turning and facing tool holder and was curious if the tangential design could be leveraged for threading. I understand that a regular tangential tool holder can be leveraged for threading by cutting additional angles to the tool. That's not what I'm after. I did some sketching in Fusion 360 and found that if you angle the tool from corner to corner about 35 degrees then the included angle of the sides is just under 60 degrees.
I haven't seen this done this way, but I haven't looked too deeply. Am I missing something? Am I looking at this correctly?
 
I believe the tangential turning idea you are referring to is a great idea and believe it’s more for the folks that have a hard time sharpening their tool bits. So it’s basically just a grind on the top. For a threading tool, the sides would also need to be ground for the correct 60° angle…more grinding. Maybe just punt and grind a normal threading tool?...Dave
 
I was putting together a design for a tangential turning and facing tool holder and was curious if the tangential design could be leveraged for threading. I understand that a regular tangential tool holder can be leveraged for threading by cutting additional angles to the tool. That's not what I'm after. I did some sketching in Fusion 360 and found that if you angle the tool from corner to corner about 35 degrees then the included angle of the sides is just under 60 degrees.
I haven't seen this done this way, but I haven't looked too deeply. Am I missing something? Am I looking at this correctly?

The Diamond tool holder by Eccentric engineering claims to be able to be used for screwcutting, but I gather you do need to grind extra angles on the toolbit, but I think they provide am gauge for this.

can you post a pic of what your proposing, might help to see if it will work, can't visualise it. Pity they don't make triangular HSS tool bits, there's your 60 deg. right out of the box.
 
The Diamond tool holder by Eccentric engineering claims to be able to be used for screwcutting, but I gather you do need to grind extra angles on the toolbit, but I think they provide am gauge for this.

can you post a pic of what your proposing, might help to see if it will work, can't visualise it. Pity they don't make triangular HSS tool bits, there's your 60 deg. right out of the box.

I also am not sure of the proposed design without a picture.

In the US A.R. Warner makes HSS triangular inserts for their tools. Some are for threading.

A.R. Warner inserts page
 
I believe the tangential turning idea you are referring to is a great idea and believe it’s more for the folks that have a hard time sharpening their tool bits. So it’s basically just a grind on the top. For a threading tool, the sides would also need to be ground for the correct 60° angle…more grinding. Maybe just punt and grind a normal threading tool?...Dave

It's not really for "folks that have a hard time sharpening their tool bits". It's more about a better way to use and hold your toolbits, Sure the grinding process is much quicker and more simple, so it saves time even for those that do know how to grind them. holding a tool bit tangentially is a much stronger way to hold it.

The forces on the tool bit are longitudinal rather that transverse, in normal turning the force is trying to bend the tool bit and break it, In a properly made tangential holder the force if excessive will just push the tool down into the holder rather than break it.

Being stronger it allows you to change from say a 3/8 tool bit to 1/4 saving considerable cash and even more grinding time. you can even use odd pieces of round tool steel such as broken center drills, etc.
 
I am a fan of A R Warner's stuff, for sure.

Here's a view of the toolholder. I've set it up to be able to rotate to accomodate helix angles, but I'm starting to wonder if it's necessary, and recognizing that rotating to accomodate helix angles will inevitably change the inclusion angle, which defeats the whole purpose of doing it this way.
tool holder threading assembly v4.png

Here's a top view:
tool holder threading assembly top view.png
 
I am a fan of A R Warner's stuff, for sure.

Here's a view of the toolholder. I've set it up to be able to rotate to accomodate helix angles, but I'm starting to wonder if it's necessary, and recognizing that rotating to accomodate helix angles will inevitably change the inclusion angle, which defeats the whole purpose of doing it this way.
View attachment 270534

Here's a top view:
View attachment 270535
Looks to me you're over complicating the idea, and kinda defeating the purpose, have a look the Diamond tool holder from eccentric engineering to see how it's done. .eccentricengineering.com.au
 
I'm aware of the diamond tool holder from eccentric. It is a turning and facing holder and the angle the tool is held is optimized for turning and facing. I'm looking for a dedicated threading holder which means the lean angles of the tool can be made more for threading. The square can be leaned over until the adjacent faces are at a 60 degree inclusion. The tool can then be ground with whatever top rake is necessary.

I'm doing a little bit of modeling and I don't think the tool should have clearance for that without tipping.
 
It's not really for "folks that have a hard time sharpening their tool bits". It's more about a better way to use and hold your toolbits, Sure the grinding process is much quicker and more simple, so it saves time even for those that do know how to grind them. holding a tool bit tangentially is a much stronger way to hold it.

The forces on the tool bit are longitudinal rather that transverse, in normal turning the force is trying to bend the tool bit and break it, In a properly made tangential holder the force if excessive will just push the tool down into the holder rather than break it.

Being stronger it allows you to change from say a 3/8 tool bit to 1/4 saving considerable cash and even more grinding time. you can even use odd pieces of round tool steel such as broken center drills, etc.
Stronger you say? Please explain. The cutting forces could push the bit right out of the holder. Or, did you mean the tool bit is at a stronger position?
 
Re the tool mounting angle required, as shown in post #6, I'm thinking the reason no one has done it before is that the relief angle under the tip would be so much that it would be too fragile.

Tom
 
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