bill3388

My Feedback: (18)

What seems to be the best down thrust angle for the Extreme 330? I have mine set pretty neutral and really like how it hovers.
When I try the vertical climb test for down trust, it seems to pitch
to the topside. So I was wondering if anybody had done some
testing with down thrust to find what is optimum for hovering and other maneuvers. I like this plane!

George E.

My Feedback: (16)

I had the same problem. I used the dremel and notched out the rails so I could tilt the engine down a little (don't know how much). Now it climbs vertical, no more pulling to canopy.

bill3388

My Feedback: (18)

Thanks for your response Geoharry! I tried 3 degrees this weekend, but it was way too much. Failed the vertical test, and it was much harder to hover. I have since changed it back to 1 degree, but only got one flight and it was very windy. But, it still felt better than when I had no down thrust. In knife edge, my 330 wants to yaw towards the canopy side. I have mixed in some down and that helps. Has anybody tried any tuning on this characteristic?

George E.

My Feedback: (16)

Funny, most want to tuck to the gear in KE. I mixed some up with rudder and it's pretty neutral now.

Fun plane. Can't wait to fly it this weekend

bill3388

My Feedback: (18)

That really makes me wonder that most CG 330's tuck and mine wants to go towards the top of the plane. Actually from what I have read that this charactisitic has to do with the relation between the elevator and the wing. So, it is a pretty drastic thing
to change for improvement. I have some planes that are pretty neutral in knife edge and they are really fun to fly. I was wondering where you have your CG? I have mine at 5 7/8" now. I tried further foward, but it was too tail heavy for me to feel comfortable.

bentgear

You might also want ot look at the aileron position in realtion to the wing. This can cause you to trim elevator differently which can cause knife edge problems.
Ed M.

Spaceman Spiff

My Feedback: (1)

I've read in the UCD threads that some people have noticed the UCD changes KE behaviour with center of gravity. maybe the rear CG makes your pitch differently? Doesn't make sense to me but ....

It isn't hard to move the stab on a profile, just did mine in a couple hours. Mine pitches like crazy to the belly CG is a little over 5 inches from LE. It will be interesting to see if it fixes the problem.

bentgear

With a forward CG you will have a little up elevator to hold the nose up when you trim out the plane. With a rear CG you will have a little down elevator to hold the tail up when its trimmed.

Now turn it on its side in knife edge. It will follow the elevator trim angle, all other things being neutral.

Thats why I mentioned where the ailerons were set at. You change the trim angle of the plane a lot by raising or lowering the ailerons a few degrees.
Ed M.

George E.

My Feedback: (16)

I don't know where my CG is. I set it to the rear of the range and move it back until it flys level inverted hands off for 3 seconds on a 1/2 tank of gas, basically to fly neutral.

I did have to droop the ailerons but for a different reason. The plane likes to pull to the canopy in a power off vertical dive.

With a little elevator mixed in with rudder (mine is around 8%) the plane flys KE pretty neutral.

bill3388

My Feedback: (18)

I agree Spaceman, that changing the stab position on a Ex300 might not be too hard. I changed it on my UltraStick 40 which was a lot more fun. How much did you move yours? I anxious to find out how it works for you. Where is your CG and what is your down thrust? I also agree Bentgear that CG affects elevator trim which likewise has a big impact on KE. Even thought the acrobatic trimming instructions tell you to adjust the alerons to help KE trim, I found that it affects inverted flight. It's the old story that every change affects more than one aspect. I appreicate everybody's input!

Spaceman Spiff

My Feedback: (1)

I moved my stab down an inch. i get to test it tomorrow (?)

A lot of this confuses me. Everything i read here says seems backwards (no offence bros) drooping the aielerons to prevent rizing to the canopy in a dive? backwards. Yours is more tail heavy than mine so the elevators should be more down yet in KE it pulls to the canopy? backwards again?

The more i learn, the less i know. Would be nice to have this all sorted out before i had cut my plane up, tomorrow should be interesting.


Oh yea, my CG is around 5 1/8 thrust is 0 down.