Swingup external threading tool

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andyf:
As I said in the post to which you linked, Bogs, the idea is not mine. Credit where credit is due, which is to Mike Cox. By coincidence, he has an article in this month's Model Engineers' Workshop describing a nice way of securing his Norman-style toolpost so he can fit two tools into each block rather than just one.

Andy

bogstandard:
Thanks for that Andy, I always try to give the due recognition that they deserve for their hard work, as you will see in a lot of my posts. Unfortunately, by what you showed, I didn't know from whom it had originated from, and in a few minutes time, the above post will be changed to give all due recognition.

One thing I really hate is people using others ideas and making out they are their own.

It is for that reason I have gone to watermarking my pics, I know it is only very basic security, but the number of sites I have been to that use them without any recognition or permission at all astounds me.

I did get my own back on one chappie on the HMEM site that basically had almost a complete article of mine on his site about my making of an own design turbine. I deleted the youtube vids to all the links he gave. The article as far as I know is still there with no vids.

Only last week a member on here asked for permission to use my Paddleducks book on his site. No problems at all, as long as no one makes money out of it.

Thanks again

John

andyf:
Entirely agree, Bogs. Even when people have put their ideas their ideas into the public domain, as Mike Cox did with this one on the 7x12 Mini-lathe Yahoo Group along with pics of his finished product, it's only fair that proper attributions should be given. Once you have finished the device, I'll invite him to view this thread, provided your report on how well it works is :thumbup: and not :bang:

Andy

Gerhard Olivier:
Nice work Bogs

Cant wait to see where your taking this one.

Gerhard

bogstandard:
I got overpowered by heavy eyelids yesterday, so I had a fairly good session today.

I would just like to point out that because I work in both metric and imperial all the time, you will most probably notice that I will be swapping and changing between the two, and will be talking measurements in either. This is just the way I work when I am winging it, and if I pick up an imperial mic, that will be used, even though I am might be cutting in metric at the time. At the very end, when it is all finished, then we can measure up in one or the other.

So lets get on, work to do.

I left it last time with just one side cut, so the first thing that I did was to cut the other side to the same sideways penetration as the other. I am still a way off having the correct width for the dovetail, and because I am copying a known good one, it makes it dead easy, because you can just cut to the right width and guarantee it will fit, whereas normally, you will have to keep trying it onto the male dovetail.

So, what is the right width, and how do you measure it.
I grab a couple of small bars of round stock, as long as they touch both side and bottom of the cut dovetail, then it will do.

Pop them into the original like shown, and measure the distance between the two. Write it down on a bit of paper.

Then do the same with the one that is being machined. Write it down, underneath the reading you wrote down before.

Subtract the lower from the upper and divide the result in two. That will be how much you machine out from each side.

Job done.

Before taking it off the mill, I decided to chamfer all the square edges. This is a true 45 deg milling cutter, not a countersink, which you could use, but this gives much faster and better results.

As I said, it will fit and lock on if you get your measuring and machining right.

So that piece can be put to one side for now, and a start made on the toolholder swinging bit.

Mark out what I want to do with it, but the maching will all be done from datum points, not the markings, they are there as a safety precaution.

The first job was to cut out the tool recess.

Then drill out the pivot hole to 10mm.

Now because this hole has been drilled from this side, I need to make a datum that is perfectly square to the hole, so I took a very shallow cut across the face with a flycutter.

Now when it was turned over and put onto parallels, after this side is reduced down to the thickness I want, the hole will also be perfectly square to this face as well.

This is it after the thicknessing exercise. You can start to see what I am doing.

The holder was marked up again, and was given a bit of profiling.

Not quite there, but you can see how it will fit onto the block.
You might ask why the pivot point has been dropped to lower than the centreline of the cutter.
Anyone who has dealt with swept wing aircraft will understand what is called wingtip growth, where when it turns going forwards, because of the chord length of the wing, the tip starts to protrude further out.
It is the same effect on this, by putting the pivot point as low as possible in relation to the tip, when the tip rises, it will in fact make the tip retract from the job slightly, whereas if higher than the tip, the tip would move towards the job. Only tiny amounts, but everything helps in situations like this.

I gave up at that, I was hurting a little bit too much, so if all goes well, I will get back to it tomorrow.
Besides, I dropped the damned drill chuck when taking it out of the quill onto my little finger, and it is time I went to get a bit of pampering.

Bogs

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