Paramotor Torque Twist and Crash,
Florida's relentless weather perfection lured us aloft again. I got
to try Parajet's newest offering, a Thor 250, water cooled, behemoth
with thrust galore. It's ideally suited for trikes or competition pilots
powering their tiny little steeds to their maximum speeds. It's the thrustiest
machine I've ever flown with a clutch. I love clutches--simply getting
off the throttle depowers the prop--much faster than the kill switch.
The machine is surprisingly comfy to walk around with considering its
90 pound heft but you want to have the harness well adjusted.
It has lower than average hook in points which left me, at a scrawny
140 pounds, leaned way back even at the appropriate attachment hole. Not
surprisingly, torque effects were more noticeable. I took off at 1/3
power to manage it lest I twist up before liftoff. Heavier pilots won't
notice this near as much.
In the certified world this machine would likely come with a minimum
pilot weight of about 170 lbs.
Just to refresh, I'm using the term yaw for when your body is
pointing left but the wing is going right (opposite of belt drives), a
common problem on powerful machines that can twist you all the way
around in the risers. Yup, that's bad.
Here's the interesting part. I've done this test before but never to
such powerful effect. The machine has offsets on both swing arms to
mitigate the yawing portion of torque. But for me it wasn't enough -- I
still twisted quite a bit. So once I was up higher, I reached out and
pushed on the left riser up at its mallions. The goal being to increase
the riser offset so the motor's thrust pushes more on one shoulder
blade. It worked extremely well!
If you do that enough you can completely counter torque effects as
Alex Varv discovered with his machine. So I tried an experiment.
I've done this before but this time got more aggressive. When
powering up to full power, I pushed out on the left riser, essentially
increasing the offset by 4 inches. It all but eliminated the torque yaw.
Enough so that on the next pass I did it again when climbing out and it
made a pronounced reduction in yaw.
Thanks to John Erickson, classy importer of Parajet whose toy trailer
is the one to rule them all. He's now also the go-to guy for Pollini
motors, too, with plenty of parts on hand.