How would you make these

[JasonBModerator @jasonb]

No, not heard of them you will have to hunt out a picture for me.

[Neil WyattModerator @neilwyatt]

These were done with a form tool; 1/18" rod with a 1/16" hole jig drilled through it, form tool lined up on the hole, create ball, use parting tool to create stub for screw thread, part off, 'screw' tail into a die with a bit of rod through the hole.

[I.M. OUTAHEREParticipant @i-m-outahere]

I agree with Michael a form tool would give the best result .

If i had to make these i would make up a plasticine mold and press the original into this half way then fill the resulting cavity with epoxy and scrape it level with the top of the mold .

This will give a half section that can be used to trace around i would then use this to trace the profile on some gauge plate so i could machine , grind or file out the shape down to the scribed line then using the original part fine tune the shape until the profile matches exactly . Then it is harden and temper then a light hone of the cutting edge ready for use .

Depending on the op's machine he may have to waste out the middle and i would be doing this operation between centres then cut if the end and finish the crown with a file and emery .

You could use a graver but you will need to make a profile gauge which if you use the plasticine / epoxy method above you could use the resulting half section to make a gauge out of some card by drawing along one side and cutting it out .

Another three posts have appeared while imwas writing this so it may seem out of place .

Ian.

Edited By XD 351 on 09/12/2017 07:43:38

[JasonBModerator @jasonb]

Posted by Michael Gilligan on 08/12/2017 20:53:02:

Incidentally … Do you remember Pop-it Beads ?

**LINK**

Don't know about remembering them I was not even born

[Tim StevensParticipant @timstevens64731]

If hand tools make you nervous, you might try this:

Set up a short round-ended steel pointer sticking out of the back of the toolpost of your lathe, or fixed to the table where the toolpost mounts. This 'follower' will move in and out, and to and fro, exactly as the tool moves. Set up a brass-shaped cutting tool in the toolpost with a fairly narrow cutting end and a radius to match the end of the pointer. A V-tool based on a thread-cutting single-point tool would be a good start. Now mount one of the bits to be copied so that the follower runs exactly in line with its horizontal centre plane. It will need to be firmly attached to the bed, and not to the saddle etc.

I would start with a practice piece of box-wood, or Delrin, and move the tool by hand in short steps, sideways, and at each step move the tool inwards until the pointer touched the pattern. Move out, move sideways another millimetre or so, and do the same, so that the pointer rested against the pattern at every step. A further adjustment of the tool (and not the pattern) in or out (away from you or towards) should be made to get the diameter of the result to match the diameter of the pattern. This should, after any initial wobbliness, result in a finial the same shape as your pattern, but with a series of small ridges around it, all the way from base to apex. At this stage you can do the same operations on the real metal for the finished job. When you have copied the whole length, leave the part in the lathe, move the toolpost out of the way (while not disturbing the tool or the follower),and use fine files, sandpaper, etc and finish with T-cut, Solvol, or similar, using a small bit of rag for the final polish. Small rag, always, so there is nothing to catch and whizz round, taking your fingers with it. And cotton string will polish the bottoms of the grooves. Not plastic string, as it might melt.

The second copy can be done in exactly the same way, and in my experience the second finial is likely to be better, in some ways, than the first. If you are not happy with the match, make another, and as you become more expert, the differences will become negligible.

What this process is doing is exactly what a copying lathe would do, but in steps rather than continuously, and at a much more bearable cost.

Hope this helps

Cheers, Tim

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