John Scholvin

John Scholvin

still can’t fit a half-stack in the trunk

Written by jks

31 Jan 2021

on the physics of snowblowers

Observations from the field:

  • Mechanical Advantage: This unit has five forward gears of increasing speed and commensurately decreasing torque, and this gearing appears to apply to both the traction drive and the snow ejector combine. The label implies that the slower speeds are for heavy, wet snow, and so I used them today. Today’s snow is of about average wetness, but there was ten inches of it and I thought low speed / high torque was the right way to go. FALSE. About halfway through, I found that it was actually working much better at higher speed. Maybe the GoPro would have survived the whole run if I’d known that going in.
  • Universal Gas Law: Pneumatic tires seemed like a good idea when I bought it. Tuning the machine up in November, including checking and filling the tires, was a good idea, too. Failing to account for the pressure drop in those tires on a day that’s about 30º colder than when I filled them was a bad idea. (Or maybe it was just a leak.) One of the tires had depressurized to the point that it was spinning freely on the wheel. You don’t need a physics background to know that’s not good for traction.
  • Wave Function Collapse: Upon discovering I had a flat tire, I discovered that my compressor was leaking and I could not fill the tire. Was it broken before then? Or did it break when I observed it? Who can say? What difference is there?
  • Law of the Lever: this blower is back-heavy, with the center of mass of the motor being over the wheels. Maybe they’re all that way, so the weight pushes down on the wheels to provide better traction. The counter effect, though, is that the thing wants to pop a wheelie (that’s the scientific term) and the front snow intake wants to ride up over the snow. Lots of dragging it back and doing that part again. Heavy. Tiring.
  • Conservation of Matter: we get nasty emails from the village about not blowing snow into the street, but when their plows deposit a couple of tons of it on my driveway’s end, three or four times per storm, I feel no qualms about putting it right back where it came from.