Internal swing up toolholder

[Michael Cox 1Participant @michaelcox1]

I have developed a prototype swing up toolholder for internal threading. More details can be found here:

http://mikesworkshop.weebly.com/prototype-internal-swing-up-toolholder.html

I hope this is of interest.

Mike

[Michael Cox 1Participant @michaelcox1]

[Gray62Participant @gray62]

Mike, that looks like a good basis for the design, I’ve been pondering this for some time, looks like you’ve hit the nail squarely on the head here.

 

Look forward to seeing this develop.

 

regards

 

Graeme

[BogstandardParticipant @bogstandard]

Very nice indeed Mike.

 

As you have proved, getting the pivot point lower and below the tip is the secret, just like the external one, but more critical on the internal because you have less room to manoeuvre.

 

Well done.

[_Paul_Participant @_paul_]

Mike,

 

Great work.

 

Regards

 

Paul

[chris stephensParticipant @chrisstephens63393]

Hi Michael,

I thought you might like to see another version of an internal threading tool. This is the one I mentioned a couple of weeks ago in the flip up topic.

http://www.model-engineer.co.uk/forums/postings.asp?th=52176&p=2

As you have found out they can work a treat, mine goes down to 12mm thread, how about yours?

There are some other pictures in my album, Internal Threading Tool.

chriStephens

 

[chris stephensParticipant @chrisstephens63393]

EDIT,

link should have been;

http://www.model-engineer.co.uk/forums/postings.asp?th=52176&p=3

christephens

[Michael Cox 1Participant @michaelcox1]

Hi Chris,

Nice tool. It looks like you have adopted the same design concept of putting the pivot point below the tool.

My tool can go down to M10 thread.

Mike

[BogstandardParticipant @bogstandard]

Well done yous two, as they say, great minds think alike.

 

My design is now redundant, as it was near enough along the same lines as yours, just a little tighter on the pivot distance to allow even smaller threads to be cut, so I will just wait until you two get yours to a finished state and fully tested, then make my own from your plans.

 

My goal was to be able to cut down to say 6mm left hand threads, as the taps are so damned expensive.

 

John

[Michael Cox 1Participant @michaelcox1]

Hi Bogs,

I think the only limitation on the size that can be tapped is the size of the cutting tool so in principle with a purpose made small cutting tool you can achieve this.

Mike

[chris stephensParticipant @chrisstephens63393]

Hi Guys,

Indeed the pivot point is below the cutting tool, how else would you get sideways movement whilst keeping the lifting to a minimum? If there is a secret to the way it works, that would be it.

As to size of thread, clearly it is down to the size of tool used, I based mine around a standard commercially available cutting tool for easy replacement when worn out. There is no reason why a smaller tool would not work, but rigidity would no doubt suffer if too small.

 

Bog’s, it is finished and tested . As a believer in “been there, done that” I shall not be making a Mk2, unless I write it up and have to take some pictures. If I were to make another, I might case harden the pivot shaft and change the bearing material in the mounting block, but that would only really be needed for commercial use.

I did try using a spring for the return but found a weight more reliable.

I look forward to seeing your version, as I know you will come up with something clever that none of use had thought of.

chriStephens

[BogstandardParticipant @bogstandard]

Chris,

 

I explained the pivot point below and to the rear of the tool tip in my post about the external one, it allows the tip to retract back slightly, as it raises.

 

Sorry, I didn’t realise yours was a completed version, congrats.

 

Nope, your two methods are basically how I was going to make mine, except I would use a couple of ball races for the pivot bearings, and have a height /angle setting and cutting stop on the opposite side side of the toolholder, on the other end of the pivot shaft.

Nothing more.

 

Again, very well done, especially keeping it so simple that almost anyone can have a go at making one. The simplest are always the best, less to go wrong.

 

 

John

[chris stephensParticipant @chrisstephens63393]

Hi John,

Well, complete as far as I am concerned, unless I have some revelation inspiring a complete redesign. (unlikely)

 

When one works in isolation one gets stuck with what your one brain can conceive, it is always easier to look at others work and, hopefully, see room for improvements or a different way of doing the same. I think, though, that mine is as simple as you can get and quite easy to machine.

Having seen most of your posts on the Yankee forums, I know that you would have made a better job of machining the parts and added a touch of “bling” that just adds the finishing touch.

 

Had I wanted it to cut LH M6 threads I would have done much the same but used a smaller cutter. I get asked to make things like M70 x 20TPI threads (yes, mixed units just like they did in the Twenties) more than the simple ones where you can buy taps over the counter. External threads are a completely different matter, even if you have a die, screw-cutting with a F.U.T. gives a better product. For which your work in re-designing and bringing to the public, I am eternally grateful.

chriStephens

[Michael Cox 1Participant @michaelcox1]

Hi All,

I have refined my swing up tool for threading so that it now combines functions for both internal and external threading. More details are here:

http://mikesworkshop.weebly.com/combined-swing-up-threading-toolholder.html

Mike

[chris stephensParticipant @chrisstephens63393]

Hi Mike,

Looking good.

chriStephens

[BogstandardParticipant @bogstandard]

Mike,

 

This is getting better and better, you’ll soon have one that drills the hole and puts in the runout slot as well, all in one operation.

I just love multi purpose tooling, that is why I spent so much time doing my interchangeable bits between lathe and mill.

 

Chris,

 

Posted by chris stephens on 15/07/2011 13:40:05:

When one works in isolation one gets stuck with what your one brain can conceive, it is always easier to look at others work and, hopefully, see room for improvements or a different way of doing the same.

 

 

I don’t class myself as a super designer or a great ideas man, but a person who looks at a problem from a logical point of view, and then solves the problem. That is why I post such a lot of my ideas and solutions at the very beginning. You working alone only has one brain to pick, me working in the public eye, has many brains, all chipping in with ideas, and I am the first person to take on another persons idea and incorporate if it is better than mine. Plus I always give due recognition to the contributor.

Once the basic idea is out there, you can guarantee that it will be much copied AND hopefully improved upon.

 

I can’t keep secrets very well when it comes to stuff like this, as I know for a fact I won’t be here forever, so I get it into the public domain as soon as possible, not for prestige, but in the vain hope it will help someone coming along at a later date.

 

I wonder just how many great ideas have been lost because a person has passed away into that great workshop in the sky before being able to get thoughts into public print, purely because he didn’t share them in the first place.

 

I personally would love to see a site where people can suggest something in our field that requires solving, or has a mental blockage trying to solve a problem he/she is working on, then let it run it’s course, with people offering suggestions and ideas to achieve an end result, like a worldwide think tank of model engineers, with no thoughts of money making or patents, with the aim of solving the problem for the benefit of us all.

I am sure you would get some very innovative and easy solutions, just by maybe combining a few of the ideas and suggestions that people come up with.

 

You only have to look at the swing up threading tool. Mike gave me an idea, I took it along a bit, then John S came up with a solution to a major stumbling block, and eventually it got made into a working prototype.

 

Look how far it has now progressed, all sorts of different designs are now being used.

 

If it wasn’t for another member mentioning Mikes idea to me, and if Mike had thought it a lost cause not worth pursuing, it could have been lost for a very long time.

 

John

 

BTW, when I am able to get back onto machining, I will definitely be making a new one, along the lines that Mike has made.

Edited By Bogstandard on 17/07/2011 12:13:44

[Michael Cox 1Participant @michaelcox1]

Hi Bogs,

I am sure that when you make your version of this tool you will add more bells and whistles that further enhance performance and improve construction and/or simplicity.

Mike

[BogstandardParticipant @bogstandard]

Mike,

 

I am too far out of it for the moment and for the foreseeable future (if ever) with regards to making things, hence me trying to use my brain a little more.

 

If I can empty that into the public domain rather than showing things I do, then that will do me for the time being.

 

 

John

[Michael Cox 1Participant @michaelcox1]

Since my previous report on the swing tool for internal threading I have made many more tests. The tests previously reported were carried out in aluminium and the tool performed well. However, when I tried to cut threads in steel it was a totally different story. The cutting tool visibly deflected downwards at the start of the cut and this was accompanied by a great deal of chatter. Once it was well into the work it settled down and behaved much better but the first turn of the thread was very badly formed.

I have since designed, built and tested a much more rigid tool that overcomes these problems and performs well even in tough steels.

For those still interested there are more details here:

http://mikesworkshop.weebly.com/internal-threading-swing-up-toolholder-mk2.html

Mike

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