Pro series also has the electric chute rotation and heated handles -- creature comforts that don't add anything to the function -- but they are kinda fun.
Anyone know how the PowerBoost actually works? I've had one of these for going on two seasons but am not very mechanically inclined. (The few times I've opened it up was with the help of folks in this forum!)
As much as I like Simplicity machines, I don't like the electric chute control. Unnecessary gizmology. Must resist the gizmos.... must resist the gizmos....
Can't tell you how the Power Boost works. Sound like it's a load sensing system that increases torque as demand increases. I'm wondering if they use a small clutch system similar to those used in snowmobiles and automatic ATVs?.
The way they work is that the drive & driven clutches have centrifugal weights and are spring loaded to adjust the belt at a circumference on the clutch surfaces that matches the torque demand. At low speeds the belt rides on the inner circumference of the clutches where the mechanical advantage is greater due to the gearing ratio. A smaller drive gear allows the engine to rev quicker delivering more torque. As the load decreases and the engine revs up, the clutch weights force the sides of the clutch together which in turn forces the drive belt out to larger circumferences on the drive and driven clutches. This allows for closer equalization of gear ratios and delivery of horse power at higher speeds. When the machine encounters more resistance (load), the clutches automatically adjust themselves to deliver more torque. I'm not saying that's this is the same system used on the Pro series but it would certainly be simple enough to incorporate into a snow thrower.
This message was modified Dec 10, 2008 by borat
