Q. What was that again?
A. It is an electric lawn tractor with a snow blower attached to it. The snow blower has been adapted to be driven by a 36V DC electric motor.
The 1974 Craftsman 36VDC electric tractor comes courtesy of my old friend Ralph. The motor is from a junked golf cart. The business end of the snow blower is from a retired machine.
Q. What do you mean by "cordless"?
A. It's electric, but rechargeable. To be clear: it's not cordless when it's recharging. It's a lot like an electric golf cart. It has a raft of lead-acid batteries, very much like car batteries. I still don't know how long I can blow snow on a single charge I'll post that datum when I have measured it.
Q. Marielle's friend John asked, "why electric?"
A. Electric because
- it is a warm-up for my electric car project
- the fact that lawn mowers, weed-whackers, and snow blowers are blamed for more of air pollution than cars
- and finally, this has everything to do with R^3... reducing, reusing, and recycling well, reusing, at least
- the sheer delight of building the thing.
Q. Does it work?
A. I sure wish I knew. It's designed to work, and if a gas-powered snow blower works, then this should, too. But I have not yet had the chance to put it through a trial. It might just be a big sculpture project when all has been said and (not) done. More on this important question after the next snowstorm.
Q. Is it true that you wanted to make it radio-controlled, so your wife could drive it from the living room?
A. No comment.
Q. Is that thing safe?
A. So far. My guess is that OSHA and the Underwriters Laboratory would NOT certify this beast for commercial sale. However: all of the electrical circuits have fuses, there are fusible links (shearpins) on the drive shaft and on the snow blower augur. The augur can't be turned on unless the snow blower is in the down position, and you can't aim the snow blower chute back at the driver. Good start?
Q. Why does the contraption -- I mean accessory -- go all the way to the back of the tractor?
A. To create a counterbalance for the weight of the snow blower to allow it to "float." If the front weren't able to go up and down lightly, it would affect steering. Also for traction: the center of mass of the entire accessory has to be roughly in the middle of the tractor in order to keep from unweighting the drive wheels when the blower is off the ground. Fortunately, the snow blower drive motor weighs about 75 lbs. and makes a good counterweight for balancing the entire mechanism.
Q. I remember from physics class that high current is tricky to control, especially trying to shut off high current. How do you address that problem?
A. Another part taken from the donor golf cart is a heavy-duty resistive motor control. Big brass blocks provide contact surfaces, and the current makes shorter and shorter paths through the resistive coil as the wiper moves farther along the row of contacts. You do waste a little energy stopping and starting the thrower, but it runs pretty efficiently at operating speed.
Q. How long did it take to complete?
A. It took six full days. (Not all at once, of course stolen hours.) That includes eviscerating the golf cart for parts.
Q. Have you finished remodeling the family room? You started that a while ago.
Q. Are you going to use it this winter?
A. I am afraid not. On Sunday, September 13, I took it apart.
It turns out I was not the only one to have the electric snow thrower idea... not even close. By chance this summer I wound up with another free electric tractor, a GE ElecTrak E-15. (Thanks Miriam Aubrey and Dick Slade!) And Rob Vasichek sold me a snow-thrower attachment for short money (thanks, Rob!). The snow thrower about 44" wide, and this winter it is replacing the 600 Lb. Cordless Electric Snow Shovel. I call it... the Half-Ton Cordless Electric Snow Shovel. Har.
Q. If I have other questions, can I ask them?
A. You bet! Send me email!
Thanks to these fine people: