Tony, last spring I set up a temporary foundry and cut my casting teeth by casting these. They are gauge cups and clearance light housings for my truck. designed to work in either place, there are also some larger ones to house a speedo and tach.
I still haven't cleaned them up and machined them, but that is coming yet this winter.
BTW, aluminum car wheels are the best material for home foundry work. The parts pictured here used to be a Turbo 400 transmission out of a 74 Corvette that I junked.







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“He, who is without oil, shall throw the first rod” Compressions 8.7:1
Steve Peterson
Central Wisconsin

Follow The Leaders For They Know The Way AUTOCAR

Nice design on those cups Steve. very art deco just like the U-70.


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I Can Break Anything

Daryl.........Welcome back.     Good to hear you got off the ice road !.

Dan, It's been busy around here.
Steve, did you know I have this..........................



Keeping an eye on your project for reference......................




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I Can Break Anything

I did not! That is the lighter version, a U50?
I read somewhere that those weren't made by Autocar, but someone else. (Or maybe just the cab was vendor built) What are your thoughts on that?


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“He, who is without oil, shall throw the first rod” Compressions 8.7:1
Steve Peterson
Central Wisconsin

Follow The Leaders For They Know The Way AUTOCAR

A few weeks back, I posted a teaser about doing some home foundry work. 40 some years ago I worked in a foundry for a few months, (before I got smart and moved on) so I had a bit of knowledge about what I needed to do to cast some aluminum parts for my truck.
First I drew out the design I had in mind, there were several tries before I had a design that could be cast easily and had the "look" I was after.


After the drawing was complete, I started by making the pattern. I chose to make what is called a matchplate pattern. 1/2 of the pattern is fastened to each side of the base plate. The white piece was split, doweled and screwed together before machining.



I also made the mold flask that would hold the sand. Sorry no picture!
Next I needed a furnace to melt the aluminum. After looking over the options I decided coal would be the simplest for a beginner. Waste oil would need a burner, as would LP gas and I didn't want the learning curve of building a functional burner when I only planned to make a few parts. Coal is simple, I had a junk Oxygen bottle so I cut that in two and used the top half to house my coal fire. The valve was removed and an airline was plumbed up, then this was surrounded by sand, standing in a garbage can.


I welded up a crucible from 6" pipe and a piece of 1/4" plate, welded on some ears to lift it and a place to hook on for tipping/pouring.

I also made the necessary utensils for stirring, skimming and pouring, all from rebar. This was all stuff I had laying around, so I haven't spent a dime on the furnace.

I read up on foundry sand and with the help of a casting forum acquaintance came up with some bentonite clay and that along with a few bags of silica sand from the building supply store, (and a bit of water) gave me foundry sand.
The way I chose to build my pattern, a core would be needed to form the inside of the cup. I made a pattern the shape of the inside, then made a fiberglass mold from that, this I could fill with a mixture of silica sand and polyester resin. (fiberglass resin) After the resin hardened I had a core for my mold.



The actual making of the sand molds was easy for me, as that had been my job at the foundry all those years ago.

After a bit of trial and error, I got my coal lit and some aluminum melted, made a pour and the first part came out almost perfect. 2-3lb coffee cans of stoker coal would melt enough aluminum to pour 3 molds. With only one flask, I had to hustle building molds in between pours. This is the better part of 2 days of work, I think to get this many parts, I had 5 failures. for some reason the larger parts were more temperamental and none were perfect, but by making subtle changes in the finished part shape I have 2 of the 3 that can be made to work

This much of the project was done last May, but I deliberately waited until now to do the clean up and machining of the castings. (cold weather, warm basement) I had to make soft top jaws for my little South Bend lathe to hold the castings. I don't own a mill, so these were made on a table saw with a carbide tipped wood cutting blade. Because I knew I couldn't make them perfect, I bolted them on the chuck, then bored the work holding surfaces true. They might not be the best jaws, but they work for what I need, as far as tolerances.



I got the first one finished tonight.







The only differences between the gauge cup and the clearance light cup is in the diameter of the inner bore. Both the gauge and the light will be held in with a bolt from the rear.



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“He, who is without oil, shall throw the first rod” Compressions 8.7:1
Steve Peterson
Central Wisconsin

Follow The Leaders For They Know The Way AUTOCAR

Nice work Steve.  I bet you won't see many like that ..

Unbelievable, Steve! My hat is of to you sir. What is the white  match plate pattern made of, HDMW plastic? How much coal did it take for each pour? Did you say three coffee cans? Did you use a forced draft? This is really interesting. Thanks


Tony

Tony, the white stuff is Delrin. Way overkill for a foundry pattern, but the local plastic supplier didn't have UHMW in a size I could use. I was surprised at how difficult (and expensive) it was to find something I could use, wood was out of the question, because of the flutes and aluminum would have been cheaper than plastic, but my little lathe wasn't up to turning that large a piece successfully.
The whole project, including bad pours, etc. took about 60lbs of coal. 2 3lb coffee cans of coal would melt enough aluminum for 3 cups. The bad part about my furnace design, is that it can't be re-stoked on the fly. I have no way to remove ash and clinkers without letting it cool down. Thus I would light the furnace, ram up a mold, pour, put the crucible back in the furnace, shake out the mold as soon as it cooled, ram another mold, repeat, hurrying to get the 3 pours before my fire cooled off.
I attached an air hose from my compressor to the bottom of my fire pot, that way I could control the draft very well with a ball valve. I was surprised at how little air flow was needed.


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“He, who is without oil, shall throw the first rod” Compressions 8.7:1
Steve Peterson
Central Wisconsin

Follow The Leaders For They Know The Way AUTOCAR

Steve, This is all very interesting. I hope to own a small lathe some day as I spent a couple years in a machine shop. The foundry stuff you are doing is all new to me. I have never been around any form of casting. Keep us posted as this is quite impressive and interesting.

I cried because I had no shoes till I met a man who had no class.