Engine Turning/Jeweling Kit

In the Sherline tooling cabinet, we have a engine turning/jeweling kit.

1: What brand kit is this?
2: Is the kit serviceable?
3: What is the smallest to largest diameters possible?
4: Are there instructions for this kit?
5: If there are instructions, does it discuss pattern layout?
6: Is additional abrasive, such as diamond compound required?
7: Has anyone used this kit? If so, who were the results? Can you post pics?
8: What gives a better finish…this kit or the Cratex tools?

@nicksilva has taught classes on using these. They are used on the small drill press (orange) on the Sherline table.

Lots of videos: https://www.google.com/search?client=firefox-b-1-d&q=metal+jewelling

Personally, prefer brushes to Crayex, they crumble.

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Thanks for the response. Looking forward to Nick’s feedback.

Cratex has rods specifically formulated and designed for engine turning/jeweling.
https://www.cratex.com/Products/Rubber-Abrasives/Jewelling

So are the brushes that are in the Sherline tool chest:

  1. This was purchased from Brownells.
  2. I’m not sure what you mean by servicable. There are replacements for everything from Brownells. Mostly it’s the brushed that fan out despite the use of the o-rings.
  3. The kit comes with small brushes (about 1/4") but the same technique has been used in large (over 3") patterns so long as you find a brush big enough. Just look at the Spirit of St. Louis for large examples.
  4. There are no instructions, but there are some good youtube videos.
  5. patterns are just overlapping or non-overlapping circles.
  6. Nothing else should be required. The abrasive compound that comes with it works well. Old school techniques would include toothpaste as the abrasive.
  7. I don’t know if anyone has used it. I haven’t taught a class since 2016. google is your friend for pictures.
  8. I like the kit for finish. The Cratex rods are a bit oval and you get an odd scratch now and again.
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I should add that it works best on flat objects. Doing round objects is doable but you get more of an oval than a circle unless it is a large diameter rod - at which point you get a slightly better flat at the point of contact.

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As always Nick, thanks for the advice and feedback.

Noted engine turner Dr. Eamonn Keogh recommends nylon abrasive pads die cut with a hole punch and used with a light lubricant such as WD-40. I am assuming that he adheres this to a dowel rod. It appears that this would be an ideal method to accurately control the diameter.

There are a few different patterns that I have seen. including:

A: the traditional linear pattern with a 1/4 - 1/2 D overlap in “X” and “Y”.
B: following a contoured and/or circular parameter on a flat surface - starting from the parameter working inward.
C: a multi-level “effect” where the base pattern is tangent to tangent then a second pass (top layer) is made over the tangency points.

Each of the above produces different visual effects.

A key to excellent engine-turning/jeweling is to begin with a polished and scratch-free surface.

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I used our Brownells kit this past Saturday with mixed results…

1: I actually came in to work on a different aspect of my project, but of course the needed Woodshop equipment was not serviceable. So I proceeded with Jeweling/Engine Turning experimentation. I was not fully prepared for Jeweling, but nonetheless, gave it a go.

2:The various Machine Shop Committee members did not witness, as they were pre-occupied with the new shop conduit installation.

3: Material: K & S Stainless Steel sheet 430 2BA finish clear PVC 1 side.

4: Machine Used: Used Bridgeport w/DRO (used calculator and notepad to document X,Y coordinates).

5: I constrained a brush with both a piece of supplied heat shrink along with one of the supplied “O” rings.

6: Mixed the supplied abrasive compound with the cutting fluid and dabbed on the sheet metal.

7: Touched off and set the quill stop. Raising the knee 0.010 - 0.015 increases the circle diameter.

8: I was able to vary the diameter from 0.125 - 0.375. The diameters stayed consistent. X, Y spacing was perfect.

9: The main problem and flaw I did not see until after I finished the project. The brush had cupped and the center of each circle was not finished. Other than that, it came out very nice.

I am going to run another experiment using a rockwood stick and Clover Lapping Compound. Rockwood sticks are used with diamond compounds and solvents for polishing and finishing operations. It was also recommended to face the Rockwood stick (or dowel rod) with leather).

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I would use more than one O ring on the brush. Hell,I’ve put 3 on occasion. what also works is to use some twist ties to keep the brushes from spreading out.

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