ericdolphy

Dear all, hi !
this is my FIRST POST ever on RCU ! Thank-you RCU for hosting me.
I'm an italian RC model airplane enthusiast, 54-year-old and still busy on the hobby.
I have a flying problem with my Multiplex Parkmaster 3D foamie, which I keep as an everyday always-in-the-trunk practice model.
I really wish some of you to give me a piece of advice on that. This is the problem:
the model flies fine straight and level, even at very low speed, with a slight up elevator input, NO BAD TENDENCY.
But when I turn it in a full nose-up-attitude harrier (full-up elevator and just enough throttle to keep altitude around the field at ridiculous forward speed), the model shows a severe tendency to roll to the left, and I have to feed significant right aileron to keep wings levelled.
If I even release a bit of right aileron, it immediatetely banks to the left. It's a real fight !
The reaction seems to deal with the prop because, with motor off the model makes a quite nice harrier descent with leveled wings, without any bad tendency to bank, but as soon as I apply a slight throttle command, ...here we go again, the left wing drops, ...and the fight begins.
Like many others at the field, I use the Multiplex recommended motor and a 10x4.7 APC-E Slow propeller.

Just consider that all other Parkmasters at my flying field here in Italy do not behave that way !

I tried with some weight on right wing tip, I moved the CG aft, I tested various right-thrust setups, and even tried a mixing where both ailerons come up slightly with full-up elevator input. I also checked the fuselage with a laser line: it's straight.

I love this model, and I'd like to use it frequently for practicing 3D, before attempting new manoeuvers on my Sebart Katana 50 and Sebino Staudacher, but, with this behaviour, it's quite hard.

People of RCU, please give me some suggestions. I'd appreciate them very much.

Being my first post, I hope that all above complies with RCU Policies, pls. kindly confirm.

Thank-you
Roberto, Italy

dimitrio

hi roberto

im not an rc expert but theres a few things that cross my mind reading your post
1st its a bit stupid but usually its silly things that give us trouble.. try to setup your plane in another memory of your tx maybe there is a false mix on this one witch you put accidently if that dosent do it have someone holding yourplane and apply foul throtle and poul elevator up and check if both halfs are moving in the same degrees maybe your right half backs up from the wind resistance. and finally you can try some right aileron mixing when foul up something like 4 or 5% and see how it does...


hope you solve your problem and have endless harriers

Beachcomber

I'm no expert either, but here is my thoughts.

It sounds like your motor/prop, which is probably turning to the right, is causing torque on your plane, turning it to the left. That's not unusual. But if the others at your field don't do that, compare your motor and prop with them to see if there is a difference.

If that doesn't help, then try mixing throttle to right aileron, if your radio will allow. But that might mess up level flight.

Another thought is it could be tip stall, and I'm not smart enough to tell you how to fix that.

TedMo

From what I read here you seem to have considered about what I also would have. Only other thing I think of is that it is torque causing problem, therefore try several different size and pitch props.

Beachcomber

Wonder if Mr. Eric got it sorted out?