Tuesday, September 9, 2008

Making a DIY homemade Supercharger

Originally I wanted to make my own small engine supercharger. Or at least find out how difficult it is to make one. There are other alternatives for small engine superchargers such as smog pumps, crankcase vacuum pumps, and the chevy oil pumps. But all of those would have trouble supplying a decent amount of pressurized airflow to a small engine.

I think a small roots type supercharger would work out nicely for a small motor, but the thing is that there does not exist any. So i decided to make my own.

After some planning and drawing diagrams on random pieces of scrap paper i realized that it isn't as difficult as originally planned. the rotors are actually quite easily made. The only hard part is attaching the gears to the thing, because currently i have no ability to make gears.

I decided to mock up some blower rotors in wood first as an experiment to see how easily i can get it to somewhat resemble an supercharger.



Making that was surprisingly easy, all i needed was 2 hole saws for the inside and outside diameters. I cut out cylinders with one hole saw and used the other hole saw to notch the center part for the rotors to be attached to, basically 6 equidistant notches in a circle made the center part. Looking at this design i realized i could just use a hole saw to cut out the center part from a plate of metal and then weld/solder/braze/glue cylinders of tubing onto the center, and i would have some easily made roots supercharger rotors.
I could extend this step to make rotors as long and big as my drill press could handle, could be an interesting project later on when i start making them for bigger and bigger engines.

Now the next step is making some gears to prevent the rotors from constantly grinding each other. The rotor case should be easy enough to make, using a fly cutter to bore a hole. Making gears is the hardest thing for this project. I will try to make some gears from wood as soon as i get some gear tooth cutters.

My emphasis here isn't really on precision, mostly the bang for buck rating. If I can make boost on a wood roots blower i would use a wood supercharger hehe. Of course if the wood one doesn't last as long as expected then i would try to remake everything in some other cheap material such as plastic or mild steel.