Pulley and Bearing Block Casting

Warming up the crucible

Some more fire pics for 'ya. Warming up the crucible and furnace on some twigs and bark (bad idea, all the sparks and ash that get blown out later really suck). I added the aluminum soon after this.



Skimming the aluminum

About 10 or 15 minutes later, the metal's all melted and ready to skim. It was full of junk, mostly bits of charcoal blown out from below, not much actual dross.



Mold is poured

Poured the metal. That casting was heavier than I thought, maybe 2 pounds (but then again, my hands aren't very well calibrated for weight). Left two and a half ingots, those go back in the pile with the rest of this alloy (engine casing) along with the sprue and gates I cut off the casting.



After Shakeout

Here's the casting after shakeout, cope (top) side on the left, drag (bottom) side on the right. This new sand - my old silica-based mixed with some fresh-mulled generic sharp construction sand - seems to work well in molding, but gives a rougher surface to the casting. Guess I need to find some real fine stuff for a facing sand...

In case you were wondering what these are for, the grooved casting is a pulley, and the uh, the other one is a bearing block (the last one (of four) I need for my wood lathe project).. mounts via the flanges on the bottom, shaft goes through the round section at the top (the hole in the middle is officially to save metal, but I doubt I'd notice that much missing metal considering the weight of these things anyway). They are designed to have the top cut off, allowing some bolts to clamp a babbit journal in a hole bored in the center of the round section.


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