The tooling looks to be castable thermoset tooling plastic, could be epoxy or urethane based. Some have fillers for improved material properties. I've made a lot of pattern tooling with the latter, and a supercharger is a great use of the time and material, especially that venerable version. Thanks for the post. Best, Kelly
Glad to contribute. Concidering the cost of those things I’d definitely be spending the time to cast one as well. Of course you would still have to fabricate the entire blower but still. Not a whole lot to them if you know how they’re built and understand they’re function. Glorified high volocity fan.
More to it than meets the eye. The Housing is the least of it. The rotors are close tolerance parts and load and thermal growth are a critical factors. Best, Kelly
Nice ESC The shells aren’t the hard part, it’s the guts that are the fun part. Takes more than a furnace...... But not telling you anything new.
Ive ventured down this road. It is easier to buy and eaton 90 off e bay for about $100.00 and then make a new housing to fit the rotors into than trying to make everything yourself. Gears shafts rotors bearings all salvaged from your "donor" and then just redesign the housing. I bought my eaton 90 for 30.00 at a swap meet. So far I have only made it as far as cad modeling the housing. Still need to finish the big mill before moving onto the patterns...
I'm going with a straight two vane. I did cast these, but had to add to the pattern for some machinery allowance.
I wonder how they machine the rotor surface: maybe with a few custom form cutters to get the various inner and outer radii. I'd be tempted to have a dedicated tool steel cutter shaped like a number '3' to mill one side along the length in one go, then flip the rotor over and do the other side. A tungsten carbide cutter would be eroded by a high silicon cast alloy so cheaper, resharpenable tool steel form cutter may be preferable.
Making a dedicated cutter is a possibility. Writing a G code program for the straight vanes is also a possibility. I had thought that I could sinker EDM each face with a copper electrode cut into that rough "3" shape. There have been examples at small engine shows of 1/4 scale spiral impellers done on CNC. Things of Beauty. The size all comes down to the pitch circle diameter of the gears. Once that size is fixed the rotor shape must conform and not gap at any angle.
