I Have OMP Edge 540 that I balanced per blue print. Two weeks ago My friend put it in the air and said it was really nose heavy. He said he could tell because when he put it in a knife edge the nose would fall. So today I put some lead on the tail and went fling and it was still doing it (acting nose heavy). The only thing that changed was it became more unstable. I don't know what to do? Should I take the lead off? I just want to have fun with it before it turns into tooth picks.


Thanks, John

I don't have experience with that plane, but if it were me I would balance it acording to the plans and let er rip. If you think it flies ok, then have fun with it. Might make sure you have enough rudder authority to KE.

Thanks...Do you know if it matters on engine proformance if the fuel tank is higher then the motor? Its a Satio 72.

Thanks, John

The best way to check and see if your CG is where you want it for this type of plane is to roll inverted. You shouldn't need more than a very slight touch of down to keep the nose level. Many 3D ships are set up to fly hands off inverted, or even climb. I prefer to have mine set up needing a touch of down. A tail heavy set up is not needed for good 3D. So its open to interpretation and preference, but if you need more than a touch of down move the CG back. I had that plane for a long time. It will tolorate a very wide range of CG placement with no ill effects. You wil find, however, as you move the CG back coupling wil change and pitch will become more sensitive.

Not every plane will knife edge perfectly. It's been a while since I flew mine, but I remember it did couple a little bit. To tell if your balance is off in KE, if it flys to the belly, it's tail heavy. Flys to canopy, it's nose heavy. The reason being, in those balance situations, your elevator is compensating for the balance. A nose heavy plane will dive by nature, and a tail heavy plane will climb. So to make it fly level in normal flight in those situations, you compensate with elevator trim. When you go to ke, you will see the result of it.

Really the best way to tell if you're balanced ok is how AeroDave suggested. Roll inverted and see how it goes. Also, if you jump over to the pro bro site and search for balancing a profile, there's a really good write up on all the steps to balance a profile out for all points. Hope this helps!

Thanks for the help. Any input on my fuel tank being higher then the motor and carb? There really is no other spot to put it.



Some pics of where I mounted it.

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I don't see it as being a problem. That's where they are usually at on most profiles.

On some of the fattys (ARFs) with inverted installations the fuel tank would be above the carbs and fuel syphoning was a problem. I don't think your installation poses a problem, though. I try to keep mine in line with it but sometimes there's just no place else. I have, on occasion, put the tank in the wing if I had a really short nose moment.

Snap it,

The tank should go on the center line even with the engine. This is where everyone mounts it. Not sure why you are having trouble as there is nothing in the way on the left side of the fuse. Mount a 6 oz tank just opposite the engine back against the wing.

Mike's right. I didn't look closely at your pic. Here's one I'm finishing up today. Tank is even with carb.

Yo Dave, those have to be the longest fuel lines I've seen on a profile!

Yeah, I know! It was a bear to get the motor tuned! It happened because the nose moment was so short the tubing actually had to go BACK to the fitting. odd.......

Your problem could be with servo blow back. Maybe a bad servo or one that doesn't have enough torque.