Lathe Parting Tool holder

[jcdammeyer]

I stumbled on this rather long video. I've never had great success parting off even though my South Bend cross feed is designed to to be pulled into the work I still have it jam often when parting.

This is an interesting solution.

As well as the original model from a guy named winky.

 

[DavidR8]

I stumbled on this rather long video. I've never had great success parting off even though my South Bend cross feed is designed to to be pulled into the work I still have it jam often when parting.

This is an interesting solution.

As well as the original model from a guy named winky.

I have yet to try parting on my lathe so I will definitely watch these.

 

[jcdammeyer]

Should have said designed to be not pulled into the work which is why a rear parting off tool isn't required.

 

[DavidR8]

Mark's is certainly easier to make.

 

[DavidR8]

 

[DavidR8]

 

[Susquatch]

@David_R8 @jcdammeyer

Can you guys part upside down in reverse on the front or in forward on the backside? It's an easy elegant solution to an old problem. No special holders are required.

I've gotten a lot better at parting as time passes thanks to some advice from @Darren a year or two ago and a nice carbide tool gifted to me by another member. The best way to say it is: No pussy footing allowed......

The old rigidity rigidity rigidity certainly applies, but it wasn't always enough for me. Thanks to Darren I've also learned to be bold. I think we are all afraid to drive hard and fast. Too many bad things can happen. But parting seems to be one of those tasks that doesn't like timid cautious machinists.

Nuff said.

For those times when NOTHING else works, upside down in reverse ALWAYS does! I've never tried backside in forward cuz I never needed to. But for those with screw-on chucks, it ought to be the same as front side in reverse.

 

[DavidR8]

@David_R8 @jcdammeyer

Can you guys part upside down in reverse on the front or in forward on the backside? It's an easy elegant solution to an old problem. No special holders are required.

I've gotten a lot better at parting as time passes thanks to some advice from @Darren a year or two ago and a nice carbide tool gifted to me by another member. The best way to say it is: No pussy footing allowed......

The old rigidity rigidity rigidity certainly applies, but it wasn't always enough for me. Thanks to Darren I've also learned to be bold. I think we are all afraid to drive hard and fast. Too many bad things can happen. But parting seems to be one of those tasks that doesn't like timid cautious machinists.

Nuff said.

For those times when NOTHING else works, upside down in reverse ALWAYS does! I've never tried backside in forward cuz I never needed to. But for those with screw-on chucks, it ought to be the same as front side in reverse.

I haven’t tried it because until this lathe I have never had a cross slide that would allow for rear tool mounting.

I’ll look at some rear tool mount ideas to see what might work for me.

 

[Ironman]

I like the simplicity of the Winky tool. The eye opener for me was the P series tool, and great that it is not high speed steel. I never knew that type existed before.

 

[jcdammeyer]

Given the loads parting off appears to produce I'm not sure I'd want to do this in reverse on my SB for fear of spinning off the chuck. All it takes is one time...
And there's no way to mount it behind. But then again the way the taper attachment cross slide is designed it's not supposed be able to dig in when parting from the front in forward. Maybe if it wasn't such an old worn lathe...

 

[DavidR8]

Given the loads parting off appears to produce I'm not sure I'd want to do this in reverse on my SB for fear of spinning off the chuck. All it takes is one time...
And there's no way to mount it behind. But then again the way the taper attachment cross slide is designed it's not supposed be able to dig in when parting from the front in forward. Maybe if it wasn't such an old worn lathe...

I think I'd build the parting tool holder in the last video I posted. The Armstrong style holder idea is from the vintage of lathes with thread-on chucks where parting off in reverse wasn't an option.
Mark's lathe is definitely not a spring chicken and his parting under power feed is darn impressive.

 

[whydontu]

Not sure if I’ll build this parting tool holder, but his drill press tap guide is brilliant!

 

[DavidR8]

Not sure if I’ll build this parting tool holder, but his drill press tap guide is brilliant!

Mark (Winky) does some very clever work. And he's a nice fellow to deal with.

 

[terry_g]

When I got my SouthBend 10K lathe years ago one of the things I could not do was part.
My employer hired a mechanic that many years prior was a machinist on an aircraft carrier,
back before carbide tooling. He told me to bring him my parting blade. He took the blade and
clamped it in the vice and heated the tip with a mapp gas torch to a dull red and peened
it slightly so it had a bit of side clearance, then he ground the cutting face slightly rounded.
He knew what he was talking about as I was able to part very successfully with it.
The blade pictured is a 3/4" Eclipse.

The tool holder I used it in is the steel block on the left with the drill chuck on the other side.

 

[Susquatch]

I’ll look at some rear tool mount ideas to see what might work for me.

Sounds like a plan. Don't forget it doesn't have to be solid. Unlike regular parting where rigidity is king, the whole idea is to be forgiving.

The tool @terry_g shows above is how I grind my HSS parting blades. But I like T-blades cuz they don't need to be peened.

 

[Bandit]

It seem a lack of side clearance is also a problem, even with t-blades, likely due to heat expansion as cutting. Thus making the peened blade easier to use, and don't need to set blade at a perfect rite angle to work.
Many times while parting deeper cuts, have pulled back and shaved a little extra off of one side for clearance. But, not able to in every circumstance.
I seem to remember using some inserts one time, that were fairly wide at the tip and having a lot of side clearance, but also had a v shaped nose/cutting edge, allowing shaving sides of cut as/if needed.