Michael Grant's leaf vacuum trailerMichael Grant told me about his homemade leaf vacuuming trailer. That got me curious, so I had to visit him to check it out. And take pictures and videos, naturally!
The leaf vacuum is a a very simple affair. It consists of a blower, powered by a used lawnmower engine, a 5" dust hose, borrowed from the wood shop dust extractor, and some pieces of heating duct connecting the hose at either end.
Old lawnmower engines are useless for most applications because they have to be run with the shaft in a vertical orientation. But for this application, Michael just mounted the blower horizontally.
The hose is slightly longer than it needs to be, but that's because it's only borrowed for this purpose. The hose goes back on the dust extractor once the leaf vacuuming is done.
The vanes have a profile milled into them to make them lighter. Michael cut that profile with his CNC mill.
Michael used a Bill Penz blower design to base his blower on.
I asked Bill Penz for permission to use this image. Bill Penz added:
"Please warn then that if they donít use a material handling impeller (meaning plastic or aluminum) or if they hit a branch or rock they could get seriously hurt. Iíd also recommend making the blower with a double wall."
With the engine running at 3500 RPM, the tips of the fan blades travel at about 65 meters per second, or about 234km/h (146 MPH). That's fast, but not bullet fast, so a reasonably sturdy enclosure should be able to contain a catastrophic impeller failure.
Michael Grant does custom electronic designs: Krazatchu Design Systems