"One Perfect Part at a Time"


“Proofs” of Concept

I was doing some product research today. This is something I made in about five to six hours. I had been thinking of how I was going to make these all week. I just needed a good Saturday to give it a shot.

As the title indicates this is a proof of concept not a real project. I didn’t want to slow myself down doing all the pictures of the process. The process is still experimental so  full disclosure can wait until a better time. I have my camera at the ready.

Long time readers know I have experimented with pewter casting before. Here is the LINK.

The “thumbs up” graphic is a 3-D rendering received free with the Vectric Aspire software. I used it to create the medallion. The finished result is seen in the first picture above. The picture was created within the software. I combined the thumbs up with some freelance drawing to form the disk. Actually in my opinion the disk is much thicker than it should be.

The edges of the disk did not come out well in the tool pathing. I need to find a better way to create the disk in the software. As this was a trial, I didn’t want to spend all day on the drawing so I accepted some imperfection in the edge rendering and moved on.

Next I had Aspire produce a roughing toolpath for a 1/8 inch ball nose mill bit. Then I had Aspire produce a spiral finish pass with a 5/32 inch ball nose. The disk is 1-1/2 inches in diameter. The aluminum (both pieces) is 1/4 x 3 x3 inches. The back plate is not machined in this test trial.

The machining was done on the CNC Taig mill. A… Continue reading

…and a cast of thousands.

That’s a famous movie intro tag from when I was a kid. (Ben Hur, Moses and The Ten Commandments, etc.) In this case the “cast” is a bit different. No Charleston Heston. Yes, a pun.

The process here is casting pewter into a mold. Perhaps thousands could be made given enough time. What I find interesting is the use of a rubber mold. When I was much younger I remember toy soldiers cast in metal molds. (The metal ones are still available.)

The mold shown here looks like it was made with hot vulcanized rubber but hot metal casting process is also shown to work with RTV (Room Temperature Vulcanization) rubber. Of course metal and plaster molds can be used.

You will notice a few have short guns. The pour was a bit too cold and the flow didn’t get to the end of the rifle. Thin parts like that are tough to fill. I cast many more than shown here (just remelted them) before I got the process right.

All I did for the pictures was cut off the sprue while still hot and then file the flash from the bottom so each one would stand up. No clean up of the casting at this point.

My plan is not to make toy soldiers. This is just an inexpensive all-in-one kit I bought on sale to get the “hang” of casting pewter. I plan to make and cast my own mold designs and perhaps offer them for sale (the molds and what they make).

I choose pewter and this variety is lead free. There is so much concern about the “dangers” of lead, it is not a good idea to offer it to the public. Of course the other metals in pewter are not intended for… Continue reading

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