A concept about single point threading

[Blogwitch]

Just something that I have been running with that I thought might interest a few of the members. It is just coming to it's final conclusions.

http://madmodder.net/index.php?topic=2323.0

Blogs

 

[mklotz]

Let me chime in here and encourage everyone to take a moment and look at what John has done. It's a tour de force of self-made tooling inventiveness and something that many of you will probably want to duplicate. Don't miss it!

 

[PhillyVa]

I agree a fine piece of work and simple too.

Philly

 

[vlmarshall]

Very nice. I discovered it on YouTube last night and read the MadModder thread earlier this morning.

 

[putputman]

I think it is an ingenious tool, and sure makes quick work of thread cutting.

Of all the lathes I have run, I have never run one that could stop that fast. Most of them coast to a stop. Obviously there must have been a brake system on that lathe. What kind of lathe is it.

 

[Blogwitch]

Thank you very much for your confidence in this offering gents.

For those that think it might not be for them to go searching on another site, or for the newbie who thinks that single point threading isn't for them, then I would suggest they have a look at this vid.

[ame]http://www.youtube.com/watch?v=8JFdNaBD5GM[/ame]

It isn't a concept that I thought of, but one from a chappie called Mike Cox. There were issues raised that in it's original form it wouldn't cut left hand threads and also it couldn't get close enough to the chuck. I just took it a couple of stages further, and then realised it could really make screwcutting just another easy machining exercise rather than something to be feared, especially for the new to machining people.

BTW, the lathe is one of the far eastern ones that are so hated by a lot of people, and yes, it has a foot brake, but that should not affect the way this tool works, as most people use a runout slot anyway.


Blogs

 

[steamer]

Nicely done John!

very nice, would you be willing to do a post on its construction?

Dave

 

[mklotz]

Nicely done John!

very nice, would you be willing to do a post on its construction?

Dave

Eh, Dave, take a look at the URL John posted in his OP.

 

[Twmaster]

Bogs, thank you. I've been following your work for some time now. The thread on MM about repairing Darren's lathe was what originally caught my eye.

This threading tool is brilliant. I need to learn how to single point. This just makes it that much easier for a relatively new-guy like me!

Thank you.

 

[deere_x475guy]

Nice job John!

 

[steamer]

Yes Thanks Blogs.... :bow:
Dave

 

[Deferr]

This type of tool holder along with an http://www.gadgetbuilder.com/ThreadingTools.html#AutoStop could be a very nice combination for lots of threading operations.

 

[rake60]

Great tutorial on slow speed threading John! :bow:

Rick

 

[Blogwitch]

Rick,

Sorry about the long wait for a reply.

I ran it slowly to show the concept of the tool lifting on the backrun. Normally I would cut a lot faster than this.

In fact over the last few weeks, I have cut all sizes of threads using this tool, and have yet to have a bad result.

It is about twice as fast as I normally get a thread cut using the drop in dial. So one redundant drop in dial.

It is a shame that it will only work with a lathe that can reverse the chuck rotation, but most new lathes nowadays are able to do that anyway.

Here is a very short clip of a large thread being cut. It shows the lifting mechanism to the full

[ame]http://www.youtube.com/watch?v=FA1xMObOPh0[/ame]

Blogs

 

[Deanofid]

I read your article when it first showed up here as a link, John, but for some reason didn't comment on it here. Let me make amends and say how much I enjoyed the write up.

It is a shame that it will only work with a lathe that can reverse the chuck rotation, but most new lathes nowadays are able to do that anyway.
Blogs

I'm in this situation, and have been with every lathe I've owned. However, when cutting metric threads on my American lathe, there is no way around running the spindle backward to get back to home base. I have a hand crank for mine because I can't reverse the motor.

I think this tip up tool would still save a lot of fiddling around when cutting metrics. The lathe has to be hand cranked backwards anyway. Not having to fool around with the cross slide to clear threads after every cut would be one less thing.

Dean

 

[Blogwitch]

Thank you Dean.

I used to have an Atlas, it didn't have reverse initially. I bought an NVR with a built in changeover switch and wired it into the motor so that it could reverse, purely for when I did metric or wierd thread setups.

5th picture down

http://www.chesteruk.net/store/tooling.htm

It was only about 20 bucks, and worth every penny.

John

 

[Deanofid]

Thanks John.
As far as I can tell, the motor on my lathe will only turn in one direction. It has a cap with only two wires. Reversing them doesn't make a difference to it. I still have my crank!

That link will do someone else some good, all the same. There are similar switches available in the States.

Dean

 

[rake60]

That is a nice bit of tooling.
I do have to say, seeing that threading tool stop dead at the end of
the cut had me grabbing for a clutch lever that isn't available on my keyboard.


It appears to draw down as it starts into the cut. What affect does that have on
the lead in thread?

Rick

 

[Blogwitch]

Rick,

It does look a little scary, as I have a very good foot brake on my machine. But the tool is no different to using a normal threading tool on a standard lathe. The only difference, is that you don't have to retract it when you wind back to the beginning, in fact, you put your next cut on as you are waiting for it to wind back to the start position. As soon as it drops off the end, you put your machine into forwards motion straight away.

The vids were taken just as the tool was finished, and the swing up was still a little tight on the bottom location block. It only took a minute pressure to settle it down into the normal operating position, so didn't affect the thread start.

Now that it has been used a few times, it can be rattled like a pair of castanets.

I would just like to say, my version is way over the top, and more time was spent making the holder than the actual tool, but that is just me on the development trail.

Later versions made by other people were much simpler, and well within the realms of a beginner with a bit of hard metal experience.


Blogs

 

[Thingibob]

The strain of a sudden stop must have a part to play in longevity.

Not sure I'd be wanting to do that too often ;D