barelias

Still my pt eletric wouldnt take off from grass field even after its upgraded. I got magnetic mayehem 22turn timed for reverse,gd 600gearbox,8 nicad cell, raised gear all around,3"wheels. But still wouldnt take off from ground even though many people said that with such upgrade it should take off. i switched between gears 2:5:1 to 3:1:1.
should i make it a tail drager? or could it be because some of the thurst goes upward? should the prop be straight?
i didnt think that was a big deal. friends at the field felt that the magnetic mayhem wasnt producing enough thurst. now with this set up it should take off from grass field with 8cells, would the motor handle the 3 lithum cells i got, that is 11.1v ,would it fry the motor? help[&o]

norvelnut

Sorry to say this, but I'm not surprised. I had a PT -E a few years ago, and had to resort to "brute power" in the form of a Mega Mini-6 and * cells to get mine to ROG well. This was back in the days before brushless motors and LiPoly cells, so you could get a motor and battery with enough power and not end up with a 50 oz. plane capable of a 4-5 minute flight these days. You certainly didn't have enough thrust with the combo you tried! BTW, consider junking the PT-E and getting a Kadet EP42 and use a 400 brushless motor and 3 cell LiPoly--I get 25 oz. static thrust with a 25 oz. overall weight which makes a PT-E look anemic at its best and is aerobatic as well!

Norvelnut

Matt Kirsch

My Feedback: (21)

What prop were you using? The point of gearing down is to turn a larger prop for more thrust. If you put the stock 8x4 prop back on, total power would be diminished by the ratio of the gearbox.

These 3" wheels... Did you get light foamie wheels, or regular R/C wheels? Regular 3" wheels are HEA-VY. Probably added 1/2 pound to the weight of the airplane like that.

What kind of surface are you trying to ROG from? Heavy, thick, tall grass? ****eddaboudit.

Forget about a 3S LiPoly too. If the battery will handle the Amps, the motor won't handle the Volts. It'll sling a winding or burn out the brushes quickly. I highly suspect that your 3S LiPoly is off a park flyer anyway, and is nowhere near robust enough to take the roughly 30 Amps this motor should be drawing.

According to P-Calc: 8 Cell 2000mAh NiCD, Magnetic Mayhem, 2.5:1 gear ratio, 12x8 prop should draw about 28 Amps . That should be plenty to haul a PT Electric off short-cropped grass if the plane doesn't weigh too much.

barelias

I am using 12x8 prop, and i have used 2.5:1 and now trying 3.1:1 gear ratio,with 1800mah nicad and 60 amp speed controller,and i'm using the 3" foamy wheels. I cant say our field at hoods up burnaby park is short cropped grass .I would say grass is a little hight for taking off.

So lipos are not good ,will fry the motor. And about weight ,i know i added some weight when i raised the gear all around to clear the 12x8 prop. now what is left to do is what most friends at the club said: tricle are not good for taking off grass.

May be ill make it a tail dragger which is tough because it seems no i know did it .also, making it a taildragger would reduce the weight of the front wheel.