the all-seeingeye Thimble Making Die
Construction Diary

2003:

July 4 - 13

July 16 - 20

July 21 - 27

July 28 - Aug. 3

August 4 - 22

August 23 - 31

September

October

November
December

2004:

March

April

May

June

July

August

Rollover

September

October November

December

2005:

February

March

April

May

June-August

September

October

2006:

March

July-August

September

October

2007:

April-May

June

July

August

September

October

2008:

January

February

May

July

September

References Technical Notes Egrets and the Commodore

Note: If you found this page using a search engine, it is a work in progress-even more so than most web pages. At this time it is a draft, the experiment is not finished, and it should be treated accordingly.

I don't really need to make my own thimbles. I ordered all I needed for Pangur Ban a long time ago. But I got to thinking about how you might go about it. This little sketch (above) was my first idea.

I had some scrap cold-rolled barstock and some spare time, so I thought I'd whip up a quick proof-of-concept.

Three-part die with first test thimble

If you look at the original sketch, you'll see that my first thought was to constrain the thimble with small lands built into the curved section that would act as stops for the expanding material. For that to work I'd have to make a pretty precise form tool for the lathe, and I didn't want to go to the bother. Instead I made a tube that fit around the die where the land would have been.

Metal failure in first test

For a first test I used a section of standard half-inch copper water pipe. The pipe was loaded into the die, and a bench vice used to close it. The vice didn't provide enough pressure to close the die completely. The result was a very shallow thimble. So, I put the die on the floor, and gave it a whack with a hammer. The shape finished forming, but the thimble split along one of the striations in the original pipe. The concept appears to be working, but I need to change the material-something softer perhaps.

For future tests I'll be using this 1-ton arbor press to close the die.

Annealing

My thought was that the drawing process for the pipe had work hardened the copper. Perhaps annealing the copper before hand would solve the splitting problem.

Pipe cutting jig

There would be no reason to go to this level of bother if you meant to make just a few thimbles. Which means you'll need a more efficient way of making the short pieces of pipe. I have an inexpensive stationary metal cutting power saw. It comes with an adjustable stop for setting the length, but clamping and unclamping the pipe for each cut was tedious. So I designed the jig you see here for the saw clamp. The scale lets me experiment with different lengths to find the right one for this die, and is reliably repeatable.

Depending on the saw, you might be able to place a box or bucket to catch the cut-offs. Because the jig has no length stop built into it, I was able to rig this handy little part catcher from a block of plywood and a length of stiff wire.

Schematic of die in operation

1) The three parts of the die. 2) Thimble blank placed on lower die. 3) Barrel in place around die. 4) Upper die inserted into barrel. 5) Die fully closed with formed thimble.