Threading barrels

[Ksracer]

They are size specific and fairly expensive for what they are but pretty foolproof to use.

Those are cool. Reminds me of a conversation I read where the guy wound welding wire into an internal thread and then used snap gauges to measure the PD.

Also… stupid defiance actions!

Rim-X?

 

[jelrod1]

The 16 pitch in that picture are Vudoo and the others are RimX

 

[Greg Y]

I've had best luck with AR Warner HSS inserts. I can thread to the shoulder and get very close. The hss is friendly at lower spindle speeds and produces nice surface finishes.....and it offers the durability of hss with the ease of carbide.

Ive ground parting tools, hand ground blanks, lantern style williams and Armstrong....and I keep going back to the Warners.

I thread to the headstock with the cross and to a travel dial.

 

[TylerFromMS]

^^^
Ditto, never seen spring gages before. Definitely less headache than wires, but they're diameter and pitch specific so you need a bunch of them- and won't work on a non-"standard" diameter. I'll stick with my handful of thread mikes. Three mikes 0-1", and two 1"-2" measure every pitch and diameter I need.

I epoxied a cheap sprit level on my thread mics to make sure I’m flat and thus in the middle of the barrel. That’s my thought anyways.

 

[BAD LT]

Man waiting on my lathe has got me asking lots of questions. I guess iam just excited. Now here another guesting for you guys. What method do you use straight in with crossfeed or 29 1/2 deg compound method. What are the pro,s and cons of each. Also do any of you guy thread away from the chuck. Thanks

E

The only important thing is never set the compound beyond 30 deg. The truth is you can use any angle to zero on the compound. What happens as you change degrees it biases the cut more on the L side of the bit or insert. Most machinists doing barrel threading simply plunge cut with the crosslide when using carbide. As long as you have a lathe with a 2hp motor straight in is great. I and many others thread away from the chuck. Works great, just remember to invert your tool upside down. Also if your using carbide thread from 360-600 rpm. It creates beautiful threads. A great way to start inverted threading is to go to Mc Master Carr web site. Buy a L hand carbide 60 deg tool. Also remember to use your fish gauge when aligning your bit with the tenion It really improves thread quality. Also after your scratch cut TPI test you can run your first real cut between 0.0015-0.0020, after that keep your depth around 0.0005.

 

[BAD LT]

The Man waiting on my lathe has got me asking lots of questions. I guess iam just excited. Now here another guesting for you guys. What method do you use straight in with crossfeed or 29 1/2 deg compound method. What are the pro,s and cons of each. Also do any of you guy thread away from the chuck. Thanks

Ed

Example of reverse threading with direct plunge cut

 

[Dusty Stevens]

Example of reverse threading with direct plunge cut View attachment 1408327

Those threads dont look right at all. Not a V thread for sure

 

[DShortt]

I'm not even sure how that can be done with a 60° threading tool set correctly.

 

[Walt Krafft]

Cut a M27x3 thread yesterday. Straight feed in with the cross slide. 0.010 on the diameter per pass. Kennametal positive rake 8 pitch Topnotch insert. 420 rpm. Moves pretty quick at that speed.

 

[xr650rRider]

Those threads dont look right at all. Not a V thread for sure

Looks like somebody rotated the compound but forget to square up the threading tool.

 

[LVLAaron]

Those threads dont look right at all. Not a V thread for sure

Compound off by 30 degrees. Or other worse things.

 

[INTJ]

Is it an optical illusion?

 

[Carl S]

Those threads dont look right at all. Not a V thread for sure

Looks like the compound is set at the wrong angle.

 

[ridgeway]

Yes...angle off by 90° in wrong direction. If you feed on compound, needs kicked 30° from face. LLooksto be kicked 30° from axis. Depends on how scale is oriented on cross feed that can be confusing. Some start a zero at 6 o'clock and some at 9 o'clock.

 

[ridgeway]

Looks like the compound at 30 but he plunged straight in maybe.

You can thread with plunging directly in from beginning to end. The tool will just cut on both sides. Not a big deal for the little tenon threads, but may become a challenge on deeper course threads because the amount of tool pressure on tool. Depends on machine and tool size as well. Many ways to thread. But looks like he fed in at 30 in wrong position.

 

[sdean]

You can thread with plunging directly in from beginning to end. The tool will just cut on both sides. Not a big deal for the little tenon threads, but may become a challenge on deeper course threads because the amount of tool pressure on tool. Depends on machine and tool size as well. Many ways to thread. But looks like he fed in at 30 in wrong position.

Yes I worded it wrong. Like the tool is set at 30 instead of compound.

 

[Dusty Stevens]

Yes I worded it wrong. Like the tool is set at 30 instead of compound.

I dont know what he did, but i can tell he did it wrong. I cant duplicate it. Looks like the tooling is cutting good though- thats a plus

 

[ridgeway]

I see it all the time. The compound is angled 30 degrees from the spindle axis. The tool is fed in on compound for each pass cutting the front flank away.

If the tool itself was angled and fed directly in in X, I don't think the tool would have lasted to create the buttress looking thread.

When feeding on compound, must be angled 29.5-30 degrees from face of part. Infeed direct in X, tool needs to be square(regardless tool needs centered) but compound can by anywhere, just don't feed with it

 

[LVLAaron]

Asian lathes have the compound numbers off by 90 degrees or whatever. So he cut them at "30" but it was actually 60.

 

[BuffaloBill]

Asian lathes have the compound numbers off by 90 degrees or whatever. So he cut them at "30" but it was actually 60.

That’s my guess as well.