Lathe indexing attachment - video

Lathe indexing attachment. By Jonesey Makes. 20:25 video:

https://www.youtube.com/watch?v=ROwmfVHE6L0

Thank you for the nice use of the 'nonius' principle.

This was an interesting build. I could see for making dials, the ability to have 100/200 divisions for threaded feed screws that are dividable by 10 vs 360 1 degree increments. Seems there could be two rows of holes, 36 and 20. I have a 5C spindex, now I know how to make the Vernier/(Nonius that's new to me) index.
The issue I'm thinking is having room for the holes.
Also I don't think making it from plastic 3D print is the right material for rigidity, as that was evident in his video.

Dear Metric Taper,
The indexing things have to be reliably attached to spindle and body. (I didn't see that.)
I guess that the 3D print is rigid enough for the indexing. (wear by frequent use is another issue).
After the indexing one has to clamp the spindle firmly against cutting forces.
Ulrich

Quote:

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Originally Posted by metric_taper

This was an interesting build. I could see for making dials, the ability to have 100/200 divisions for threaded feed screws that are dividable by 10 vs 360 1 degree increments. Seems there could be two rows of holes, 36 and 20. I have a 5C spindex, now I know how to make the Vernier/(Nonius that's new to me) index.
The issue I'm thinking is having room for the holes.
Also I don't think making it from plastic 3D print is the right material for rigidity, as that was evident in his video.

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If you have a CNC, the index plates should be a fairly easy make. Failing that, you can 3d print them in PLA or wax and lost-pla/wax cast them.

Thinking about it, I think there are some things you could do to help the accuracy. E.g. Press in metal liners to the reamed holes, print the shaft holes on the components undersize and turn them to fit. Still, for a 1.0 project, it was great!

For getting that busted tap out, the alum/hot water trick will dissolve a HSS tap. It's a cool trick, and AVE is a hero for sharing it. There's plenty of room for larger fasteners on the shaft, so maybe move up to m5 or m6 on the next one to make tapping suck less.

Dear Elizabeth,
"the alum/hot water trick will dissolve a HSS tap"
Be so kind: Who is AVE? Where is his article?
Ulrich

Has anyone tried this, or can verify that it works or not
https://www.snaderflyby.com/dissolvi...um%20unchanged.

Quote:

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Originally Posted by uv8452

Dear Elizabeth,
"the alum/hot water trick will dissolve a HSS tap"
Be so kind: Who is AVE? Where is his article?
Ulrich

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I looked for any video of AVE removing a tap chemically. He has a video using Carbide and Tungsten Carbide drills where he breaks the drill tip off then goes to a carbide burr to finish removing the core of the tap, then chisels the remains out.

So searching for "alum hot water tap removal" in YouTube, I got 3 videos showing the process;

https://www.youtube.com/watch?v=hHN0v2wYjXQ
https://www.youtube.com/watch?v=JCADI0YSt8M
https://www.youtube.com/watch?v=NUPlGhuLHXo

They all appear to be successful using Aluminum sulfate, with hot water or hot battery acid mixed with alum. Boiling water temp is shown in all three of these videos.

This was AVE's approach to tap removal;
https://www.youtube.com/watch?v=1uwz7BhAWZE

I've dissolved a couple taps this way. It will rapidly oxidize the ferrous metal with out any noticeable change to the non ferrous material.