Single point threading in reverse

[KyCarl]

eBay..Flea market..Craig's list. Most of the time I don't rush..Just keep my eyes and ears open? If you have a standard and it repeats use it..I have a lot of Etalon stuff
it's really nice and they know it!

 

[Chevytruckman]

I agree, there's always something else I think I need haha. I got a few used starett thread mics off eBay...wow is that simpler than trying to hold wires.

 

[shortgrass]

Another good idea. Think a Shars would be good enough for that or need to shell out the big bucks for a starret? Every time I turn around I'm spending just another couple hundred on this dang hobby...between lathe tooling and loading equipment I'm gonna go broke. And to make matters worse I hate my little grizzly and want to get a real lathe, so that requires adding on to the shop...it never ends

There is the problem, your little Grizzly is too small. It lacks enough mass to thread in reverse with the tool up-side down. The carriage wants to lift from the ways, instead of being pushed down, just as J.E Custom and KyCarl have pointed out in previous posts. . The result of the lift is now the tool is below center, causing it to want to grab and then the tool tip breaks off. With a lathe that small you are almost forced to thread the conventional way, and there's nothing wrong with that. It is just one of the skills that needs to be learned before 'driving' a chambering reamer. It is not hard to do, even at the 100rmp 'slow' that your lathe has. Simple hand/coordination.

 

[birdiemc]

There is the problem, your little Grizzly is too small. It lacks enough mass to thread in reverse with the tool up-side down. The carriage wants to lift from the ways, instead of being pushed down, just as J.E Custom and KyCarl have pointed out in previous posts. . The result of the lift is now the tool is below center, causing it to want to grab and then the tool tip breaks off. With a lathe that small you are almost forced to thread the conventional way, and there's nothing wrong with that. It is just one of the skills that needs to be learned before 'driving' a chambering reamer. It is not hard to do, even at the 100rmp 'slow' that your lathe has. Simple hand/coordination.

I do alright threading the conventional way, I just liked the idea of reversing it to take a little stress off. Its doesn't help that I was trying on some old sucker rod I had laying around. That stuff is crap to machine. I knew better before I even tried but its what I had laying around.

 

[John Klingenberg]

Didnt specify, sorry, this was threading external threads with the tool upside down and spindle running in reverse, moving carriage left to right.

That's a link to the video I watched that inspired me to try.

The way you just described you're running it to cut on the back side of the tool. If you cut a outside thread I dont see the advantage to tool running upside down or in reverse. The advantage comes to you when inside threading you dont have to lean over the machine and see the cutting action better. If you set the cross at 29.5 on a backside cut the cross should be set at 29.5 the opposite direction towards the wall not to the operator so the stress is to the front of the cutter. If you cut on the back of an inside cut inward to out the cross has to be set to your left and it needs a longer tool to overcome the angle. If its snapping off you're running backwards or too much cut depth. Setting the cross isnt necessary all told. You can go straight in on a plunge cut but you cant cut as deep. More passes set you up for more mistakes. If you're running a good machine like a monarch 10EE or other precise machine it's not a problem to make multiple shallow passes. I find in makes a smoother cut and no burrs to clean up.

 

[Danny1788]

Cut relief grove to thread depth. Then use and internal threading bar on the back side of the tenon, lathe running in reverse thread like normal but left to right. The bar will be setup on the backside of the tenon and cutting away from the shoulder. I thread at 360RPM this way and produce awesome surface finish. It's similar to what Joe is doing in his video but the force is all down and still using the compound. Works great for cutting threads on muzzles where you want to be as close to the shoulder as possible.

 

[birdiemc]

Cut relief grove to thread depth. Then use and internal threading bar on the back side of the tenon, lathe running in reverse thread like normal but left to right. The bar will be setup on the backside of the tenon and cutting away from the shoulder. I thread at 360RPM this way and produce awesome surface finish. It's similar to what Joe is doing in his video but the force is all down and still using the compound. Works great for cutting threads on muzzles where you want to be as close to the shoulder as possible.

I'm not real sure why that's the first time I've ever heard of that method, but I cant think of a downside to it.

 

[KyCarl]

I have turned OD's with a bar on the back side of the tool post so I could cut larger parts. Watch the flex and you might want to do a true cut at your last 0..?
I just might have a bar and a few threading inserts I'll look.
I know I have a regular insert holder.