RE: Overpowered?
 

Sounds to me like you forgot to use the rudder. I've done the same thing with the same results. The first instinct sometimes is to correct with aileron, but rudder is what it needs.

RE: Overpowered?
 

Your power was to low and your take off angle is to high. Unless you have tall trees at the end of the runway you have to clear keep your take off at no more then 15 degrees. At the angle you were at and at only 1/2 throttle you were loosing speed and stalling.

RE: Overpowered?
 

Yes, if you had used rudder instead of aileron you would have more time to save it but the problem is not torque here, its airspeed. You are trying to climb at a high drag configuration with low power. The airplane is going to transfer the current kinetic energy (speed) for potential (altitude) but once the energy is gone it will be too slow to maintain flight. RC-sport also mentioned it, you stalled because of lack of speed and not enough power to continue climbing. Unless you are grossly overpowered never take off at half throttle. You experience the effects of engine torque heavily when the aircraft is at low airspeeds.

RE: Overpowered?
 

Well My buddy and I have figured it out we think. I tried the about the same setup on his G2 simulator and we got the same results as what had happened to me. The climb out was not fast enough or hard enough on the throttle and was climbing at a resonable angle but not fast enough. I think I should have applied full throttle as soon as i left the ground and started to climb. The tip stall was the same as on simulator as what really happened. I have never experienced this before but then again this is the first 4 stroke I have ever flown. i always have my 2 strokers humming pretty good as i get off the ground but i just am not familiar witht the 4 stroke sound and its hard for me to actually tell what rpm i am going. So I will chalk this one up to pilot error and hopefully this weekend be back in the sky with the new spacewalker. I am going to actually put the saito 72 back on it and let friend from a club try it out just to see if its me or not. Well thanks for all the input and advice and I will let you know how the new one flies.

RE: Overpowered?
 

Good luck with the new plane. It should be fine.

RE: Overpowered?
 

Really nice idea trying it in the simulator......[sm=thumbup.gif]

RE: Overpowered?
 

Ok while waiting for the backorder on the new airplane I decided to do a quick fix on the broken one and re-install the magnum 40 engine. The repair was quick but solid and the monokaot is not the same but it was just for a test flight. I took the airplane to the airstrip and left at a 20-30 deg. climb out. No stall and no unusuall behavior , although underpowered it climbed out at a steady speed and continued onward for 4 good flights. I just dont understand why it doesnt roll with the magnum 40 but with the saito 72 it does. I did manage to get some better video this time and it did fly quite well but I still had very little vertical but after 4 flights it is still acting normal on takeoff. Maybe a little smaller 4 stroke in the new one when it arrives?

RE: Overpowered?
 

Glad it flew well.

RE: Overpowered?
 

sounds like a trim problem, could also be part of the reason why it wanted to roll to the left. you said you balanced the airplane fore and aft, but did you balance side to side also? a heavy wing will act the same way.

RE: Overpowered?
 

I could imagine the Saito .72 wanting more right thrust angle.
That's enough engine to fly a GreatPlanes 78 in. Spacewalker.

RE: Overpowered?
 

Yes I did balance it laterally and it balanced pretty well only about 1/4 ounce off wieght so I wieghted the right wing. My giles 202 took 4 ounces of wieght and if flies great. Well it flies ok so im gonna install a smaller enigne in the new one , I think its just too much thrust for the little spacewalker. Thanks for all the responses.

RE: Overpowered?
 

FWIW, I'm flying an old GP Cap21 kit designed for a .40 2-stroke. I have an old OS .61FS in the nose, turning a 13x6 APC prop. Weight RTF less fuel is 6lb-6oz. Wing loading works out to around 27oz/sqft which is a bit high.

When I take off, I roll down the runway quite a ways. The tail comes up almost as soon as I start rolling, but I let it really get going. I gradually increase power until I'm at 100% power. That usualy takes about 150ft or so, since I add power slowly. Sometimes I'll hit a divot (grass runway) and the plane can fly at only half-power, but I keep going straight and increase power until I'm at full and going pretty fast. Then I pull in to a shallow climb.

After I've climbed for a second or two, I then have airspeed and altitude for some low-level tricks, like a roll or pulling vertical. It looks like I pull vertical right on takeoff, but that little delay is there so I know it's well over stall speed and the engine is running right.

RE: Overpowered?
 

i have one of these planes with a 46 does good i punch it give it the right amount of rdder to keep it streight intill it lifts off i do all my planes this way its the best way if you cant hold it straight you need to practice taxing intill you can
;)

RE: Overpowered?
 

Yes you can overpower any airplane but in your case I don't think your airplane was overpower. I think you may not have had an enough speed to takeoff. Just because you have all the power in the world does not mean you can take off in 20 feet. The Spacewalker is not a performance airplane so it needs some speed on takeoff.

You may not have had enough right thrust for the bigger motor.


Mike

RE: Overpowered?
 

I have a dilema. I have an ultra stick 40. The manufacturer recomends a two cycle engine up to .58. I've read that a 61 works well on these planes provided the battery and the rudder and elevator servos are rear mounted. I was looking at the tower 61 for this plane but saw the tower 75 which is actually lighter than the 61 since it is a bored out 61. The price difference is only 10.00 and the HP difference is significant. Buying the 61 isn't such an obvious choice now. If there is no such thing as overpowering, why would this combo not work?

RE: Overpowered?
 

Zetor,
As long as the CG is good. And it is built good and will hold up to the extra HP. And the prop clears the ground. It will be fine. Use good hinges.


Mike

RE: Overpowered?
 

My Seagull Spacewalker suppose to be in a day or two. I'm planning on installing an
Thunder Tiger .61 on it. I've read several things on the overpowering on it. I believe
it will be ok.
But, question is, do I need to order a bigger motor support. Being I don't have the plane
in yet. I don't have a clue. Also, will the crowl fit with this bigger size engine, and, or , do
I need to put an pitt's muffler on it to make the crowl fit, if it will fit at all ...........
I've seen pictures of this plane, see the other motors ( smaller .40 size )
are mounted at a different degree of slant .

RE: Overpowered?
 

The plane comes with a pre-installed engine mount which is rotated at about 45 degrees. A good BB 46 engine is more than this plane needs. Your 60 might blow the wings off it.

RE: Overpowered?
 

I have an EVO .46 NT on mine. Minn is right, it flies just fine. Why put a huge engine on it to add weight and fly it at half throttle all the time?

RE: Overpowered?
 

i have one seagull space walker and i'm using a saito .72 on it with no problem. until the day that i try to take off close the fancy and lose control of the airplane b4 takeoff and hit the fance and broke the wing, not too bad i start fixing the wind but decide to sell it you can check here a lot or airplanes that i have for sall and included is the space walker II. http://www.rcuniverse.com/market/item.cfm?itemID=39884

RE: Overpowered?
 

skribnod,
You are definitely experiencing tip stalls due to low powered take offs. The 72 four stroke WILL create a lot more torque than that 40 two stroke, and the effect at low airspeeds is much more pronounced.

You mentioned that next time you'll add full throttle just after it takes off; that's the worst thing you can do! That will maximize the torque effect at the lowest airspeed and almost positively result in a torque roll (stall) into the ground. You want that throttle applied BEFORE the plane leaves the ground, then be ready to apply right rudder not aileron, if it starts to roll left.

Hope you have better luck with your new one.
Dennis-