Threading without the end groove

All discussion about lathes including but not limited to: South Bend, Hardinge, Logan, Monarch, Clausing and other HSM lathes, including imports

Moderators: Harold_V, GlennW

Harold_V
Posts: 17692
Joined: Fri Dec 20, 2002 11:02 pm
Location: Onalaska, WA USA

Re: Threading without the end groove

Post by Harold_V » Sat Mar 24, 2018 4:02 pm

I'm making reference to the side near the chuck, which, when held according to the method used to hand a cutter, is the right side. I probably should have made that clear.

H
Wise people talk because they have something to say. Fools talk because they have to say something.

User avatar
Bill Shields
Posts: 5508
Joined: Fri Dec 21, 2007 4:57 am
Location: Somewhere in the World
Contact:

Re: Threading without the end groove

Post by Bill Shields » Sat Mar 24, 2018 4:13 pm

Giggle....you have never programmed a LEFT HANDED Swiss type machine with the collet on the opposite side..
Too many things going on to bother listing them.

User avatar
Dave_C
Posts: 960
Joined: Mon Apr 21, 2008 10:34 am
Location: Springfield. MO.

Re: Threading without the end groove

Post by Dave_C » Sat Mar 24, 2018 4:21 pm

I'm making reference to the side near the chuck, which, when held according to the method used to hand a cutter, is the right side. I probably should have made that clear.
Thanks for posting the explanation so the newer members aren't confused. The tool hand thing is a bit confusing at first.

Dave C.
I learn something new every day! Problem is I forget two.

User avatar
GlennW
Posts: 6757
Joined: Sun Apr 15, 2007 9:23 am
Location: Florida

Re: Threading without the end groove

Post by GlennW » Sat Mar 24, 2018 4:52 pm

DSC00856.JPG
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!

User avatar
Dave_C
Posts: 960
Joined: Mon Apr 21, 2008 10:34 am
Location: Springfield. MO.

Re: Threading without the end groove

Post by Dave_C » Sat Mar 24, 2018 5:07 pm

Nice!
I learn something new every day! Problem is I forget two.

pete
Posts: 1696
Joined: Tue Feb 10, 2009 6:04 am

Re: Threading without the end groove

Post by pete » Sun Mar 25, 2018 1:27 am

Dave, easiest way to remember the "hand" a lathe tool is would be to hold both your hands out in front of you with your thumbs pointing towards each other. The direction the thumb is pointed equals what the lathe tool does. Example right hand tool or moving from the tailstock end to the headstock end. Left hand just the opposite. Exactly why tools are termed opposite of what logic says they should be I've never read a good explanation for. Years ago one member on the HSM forum went so far as saying all the books and anyone who used what the books said for the correct tool hand were completely wrong and he refused to use what he knew were the wrong terms. :-)

User avatar
GlennW
Posts: 6757
Joined: Sun Apr 15, 2007 9:23 am
Location: Florida

Re: Threading without the end groove

Post by GlennW » Sun Mar 25, 2018 7:12 am

I just remember that it is the opposite of what you think it is.
Glenn

Operating machines is perfectly safe......until you forget how dangerous it really is!

User avatar
Dave_C
Posts: 960
Joined: Mon Apr 21, 2008 10:34 am
Location: Springfield. MO.

Re: Threading without the end groove

Post by Dave_C » Sun Mar 25, 2018 7:36 am

I actually remember it by looking at the way it approaches the part to make the cut. From the right is a right handed tool. (even though you are moving left to make the cut) I wasn't asking about how to hand a tool, I was asking for clarity so other readers would not be confused. Harold did a great job of clearing up the post and you all did a great job of adding detail and pictures.

It's all good!

Dave C.
I learn something new every day! Problem is I forget two.

drmico60
Posts: 23
Joined: Wed Oct 03, 2012 8:05 am
Location: United Kingdom
Contact:

Re: Threading without the end groove

Post by drmico60 » Sun Mar 25, 2018 11:28 am

I made an electrical autostop for my minilathe, see:
http://mikesworkshop.weebly.com/autostop.html
This auto stop was origianally designed to stop the carriage whilst it was being driven by a small DC motor.
At a later date I modified the control circuit so that it would turn off the main lathe motor. This is ideal for screw cutting because the lathe will automatically stop when the carriage reaches a certain point. Thsi later modification is described here:
http://mikesworkshop.weebly.com/lathe-m ... ntrol.html
As a further refinement I made a swing up threading tool, see:
http://mikesworkshop.weebly.com/swing-u ... older.html
This combination of lathe motor autostop with a swing up toolholder making screw cutting without a runout groove very simple.

Mike

John Hasler
Posts: 1271
Joined: Tue Dec 06, 2016 4:05 pm
Location: Elmwood, Wisconsin

Re: Threading without the end groove

Post by John Hasler » Sun Mar 25, 2018 11:46 am

Very nice. A comment, however: it is better not to use snap-action switches where you need precise repeatibility. They seem nice and crisp but they are actually not as repeatible as simple contacts.

I like the swinging toolholder idea.

drmico60
Posts: 23
Joined: Wed Oct 03, 2012 8:05 am
Location: United Kingdom
Contact:

Re: Threading without the end groove

Post by drmico60 » Sun Mar 25, 2018 12:06 pm

John Hasler wrote:
Sun Mar 25, 2018 11:46 am
Very nice. A comment, however: it is better not to use snap-action switches where you need precise repeatibility. They seem nice and crisp but they are actually not as repeatible as simple contacts.

I like the swinging toolholder idea.
Using the microswitches I get about 0.1 mm repeatability which seems to be good enough for threading. I do like the idea of a simple contact switch and when I have time I may make some experiments to see how the two types perform for repeatability.

Mike

joelallan
Posts: 13
Joined: Mon Sep 24, 2012 7:17 pm

Re: Threading without the end groove

Post by joelallan » Wed Apr 11, 2018 10:36 pm

1. Turn the threading tool upside down and level accordingly.
2. Use an indicator on the ways to set a zero reference on the carriage where the threads are supposed to "end".
3. Run the chuck in reverse from where the threads are to end.
4. Engage the half nut and advance the cutter in .001-.002" to confirm you set up the gearbox correctly for the ptich. After that never disengage the half nut until the threads are done. Move the tool out after the first cut and then rotate the chuck forwards to bring the carriage back to the zero location. If you overshoot it then move the chuck in reverse until you get back to your zero location.
5. When you are ready to turn the chuck on again in reverse advance the crossfeed in .010-.015" and repeat at the moment you turn the chuck on. Thread cutting depth is dependent on the size and rigidity of your lathe. If you get a lot of chatter back off to .005-.010".
6. When you get towards then end of the entire process make your advanvces .001" and finally no cuts at all but running ove the same threads several times. Use lots of oil.
7. Remember the process (regardless of cutting upsidedown and reverse or traditional) will create a burr on the crest of the threads so be sure to file them down inbetween checking your fit otherwise you will make your threads undersize just trying to get your nut on. A MIC is better than calipers for checking the diameter.

It is time consuming but the threads will actually be stronger than if you have a relief groove. This is the same method to make metric threads with a standard QC gearbox with a metric capability. Never disengage the half nut until the threads are perfect. I do it all the time. If done right you can even make multiple pitch threads by moving the compound, obviously for courser pitch regardless of left hand or right hand.

Post Reply