Fine downfeed phase2: casting the handwheel crank

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After a bit of hunting, I found that I could purchase a couple of bags of Petrobond casting sand from budget casting supplies over in Oakland, CA.

 

Prepping to form the mold didn't take long. I had to cobble together a quick flask and then I was ready to go. The talc is used for a parting agent to keep the pattern from sticking to the sand and the mold halves from sticking together.

 

After ramming up the mold and removing the pattern, here is what we have.

 

The detail is quite nice. I actually used the hand crank from the tailstock of my little lathe for the pattern and I'm quite happy with the results.

 

 

Fire up the old R2 unit and within 35 minutes or so, I'm ready to pour. The Petrobond smokes a bit, but it is bearable with adequate ventilation.

 

I had to mess around with the molten aluminum in the sprue and riser. I just love playing with molten aluminum. If you've never seen aluminum crystallize as it solidifies, it is truly and amazing thing to watch.

 

The moment of truth when you crack open the mold and see how the part looks.

 

Not too bad for the first part ever cast in my garage. I guess all of those metal shop classes back in high school finally paid off.

 

 

Great detail and excellent surface finish. This thing looks almost as good as the original!

 

 

After cutting away the sprue and riser.

 

Truing up the mounting surface of the crank before the part goes onto the lathe for a bit more cleanup.