First threading attempt

[Dave in WI]

On my Grizzly, if you want to cut at 29.5° you set the compound scale at 59° on mark as it reads total degree.
Edited to add: what do you guys clean up layout fluid splashes with...

 

[linebaugh]

On my Grizzly, if you want to cut at 29.5° you set the compound scale at 59° on mark as it reads total degree.
Edited to add: what do you guys clean up layout fluid splashes with...

I cover them up with Cutting fluid and metal chips and shavings. Out of sight out of mind.

 

[geo.ulrich]

On my Grizzly, if you want to cut at 29.5° you set the compound scale at 59° on mark as it reads total degree.
Edited to add: what do you guys clean up layout fluid splashes with...

acetone

 

[Lucky Shooter]

Butch----I'll throw this out for the more experienced folks to comment and grind on.

Assuming you set the compound correctly------I think the orientation of your
threading tool tip, relative to your work piece might be off just a tad.

I've heard quite a few folks talk about lining up the edge of the threading tool
with the chuck jawa or the faced-off end of the work. I've also been told by
some of the old hands that this doesn't always work with all lathes.

The little fish tail might be a more dependable answer to this alignment.

A. Weldy

 

[Butch Bradshaw]

Well the answer to the wonky thread has been found. It was because I set the threading too high evidently.
Thanks for pointing out the problem!



The tool was rubbing the bottom rather than the cutting edge .

It pays to double check your setup!

 

[geo.ulrich]

That explains it tool chipped and changed vee....

 

[carlsbad]

Chipped tool could also explain the thread profile.

 

[Butch Bradshaw]

Chipped tool could also explain the thread profile.

Actually the chip portion is beneath the cutting edge. I had it set to high...

 

[carlsbad]

Does the cutting edge have clean cutting surfaces that are both at the same angle to square? Maybe a clearer photo.

 

[Butch Bradshaw]

Yes the cutting edge is clean. The bottom of the bit was doing the cutting! Lol!

 

[jdh47]

I'm far from expert but I've never had any luck threading to a shoulder with a cemented carbide tool. Carbide does not like to stop in a cut. It likes to be ran fast. Edges break down easily. HSS is good and laydown full profile carbide inserts do pretty well if used correctly. Arthur A. Warner tool makes HSS inserts for just about any profile and they work well. You can order their stand up inserts to use in Aloris type threading toolholders.
You can also grind your own HSS bits to use in your regular toolholders.
As lathes get older and more wear on them it is beneficial to take smaller cuts when threading at an angle. It seems to be all the rage trying to mimic CNC performance in threading. Truth is it can't be done. Our lathes aren't made for it. Pretty threads are a source of joy and good to look at but they don't hold any better than less than perfect finished threads if they are done correctly.

HSS bits work well if ground correctly and honed to a good finish. Good luck, Joe

 

[ckaberna]

Well the answer to the wonky thread has been found. It was because I set the threading too high evidently.
Thanks for pointing out the problem!

View attachment 1155185 View attachment 1155186

The tool was rubbing the bottom rather than the cutting edge .

It pays to double check your setup!

I am no expert, especially with carbide but that looks more like a turning tool than a threader? Maybe the way it’s chipped.

 

[ckaberna]

Buy you one of the aloris AXA 8 or whatever size you need BXA CXA? and be done with it. Should last a lifetime for part time machinists. HSS works much better on smaller slower lathes. Carbide is for deep/fast stuff

 

[Butch Bradshaw]

I am no expert, especially with carbide but that looks more like a turning tool than a threader? Maybe the way it’s chipped.

This is the tool I'm using

1/4 x 1/4 Inch Shank, Offset Threading Single Point Tool Bit

 

[Butch Bradshaw]

View attachment 1155423 View attachment 1155422 Buy you one of the aloris AXA 8 or whatever size you need BXA CXA? and be done with it. Should last a lifetime for part time machinists. HSS works much better on smaller slower lathes. Carbide is for deep/fast stuff

That looks like a geat threading tool! I've got an AR Warner tool coming right now, but may purchase one of these at some point.

Thanks for the tip!

 

[shortgrass]

Lots of advice given so far, I'll give mine. Get a setting gauge and use it so you know the tool is properly oriented to the work (slang it's called a 'fishtail"). Make sure the tool is on center. "On center" means the cutting tip is in the center of the bar. Take a piece of scrap bar stock and turn a point on it. The point is "center". Cemented carbide will work just fine, no need for a bunch of fancy high priced tools if your on center and properly oriented. But hell, what do I know, I've only made living machining since '74.

 

[ckaberna]

The author Warner’s look great to me but the aloris deal eliminates many issues. To sharpen you just grind or file the top of the “V” the 60 degree form is made into it.
That offset is what throwed me off, never even heard of one??

That looks like a geat threading tool! I've got an AR Warner tool coming right now, but may purchase one of these at some point.

Thanks for the tip!

 

[ckaberna]

Lots of advice given so far, I'll give mine. Get a setting gauge and use it so you know the tool is properly oriented to the work (slang it's called a 'fishtail"). Make sure the tool is on center. "On center" means the cutting tip is in the center of the bar. Take a piece of scrap bar stock and turn a point on it. The point is "center". Cemented carbide will work just fine, no need for a bunch of fancy high priced tools if your on center and properly oriented. But hell, what do I know, I've only made living machining since '74.

Another way is a 6” ruler pinched lightly between the work and cutter tip and ensure is perfectly vertical to have the tool contact the center. Fellow that has been machining for many years taught me that. Quick too!

 

[Butch Bradshaw]

Lots of advice given so far, I'll give mine. Get a setting gauge and use it so you know the tool is properly oriented to the work (slang it's called a 'fishtail"). Make sure the tool is on center. "On center" means the cutting tip is in the center of the bar. Take a piece of scrap bar stock and turn a point on it. The point is "center". Cemented carbide will work just fine, no need for a bunch of fancy high priced tools if your on center and properly oriented. But hell, what do I know, I've only made living machining since '74.

Thanks for the comments! I do have the "fishtail" and use it but failed to center on the work...now I see what the importance is. Congratulations, after 46 years of machining you might have a handle on it now ;-)

 

[shortgrass]

Thanks for the comments! I do have the "fishtail" and use it but failed to center on the work...now I see what the importance is. Congratulations, after 46 years of machining you might have a handle on it now ;-)

Maybe. When I screw-up its usually because I've ignored one of the 'basics'.