Xtreme F-16 1/6.75
#302

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Location: Jacksonville, FL
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Rudder setup stock per instructions. K160 engine.Don't understand why it is so tail heavy. Weight is 27 lbs dry. Balancing with tanks empty, wheels down, no UAT, no cockpit either. Balancing about an inch back from the 190 mm recommending in instructions. That is with 2 lbs of lead in nose already. Just doesn't make sense to me. Looking for ideas on what could be wrong.
Terry
Terry
#303
Senior Member

Rudder setup stock per instructions. K160 engine.Don't understand why it is so tail heavy. Weight is 27 lbs dry. Balancing with tanks empty, wheels down, no UAT, no cockpit either. Balancing about an inch back from the 190 mm recommending in instructions. That is with 2 lbs of lead in nose already. Just doesn't make sense to me. Looking for ideas on what could be wrong.
Terry
Terry
#304

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Performed maiden today. The plane flew very nose heavy although balance was 190mm back from LE of wing at root as per instructions. So obviously this balance point is not accurate. Does anyone know what the CG should really be? I've e-mailed Extreme Jets and received no reply.as yet.I just don't understand how the manufacturer could be so far off on the CG for this airplane.The plane flew well otherwise. Landed very nose high and pretty slow.
Terry
Terry
#306


info on this sheet says 180. mine flys great, lands same as yours. elevators are almost 1/8 " up trim. same info and pictures of elevators in earlier post. adjust the cg to your style. most cg info posted is a starting point. a few flights in similar conditions helps determine what's best.
#315


I have two 2700 mah receiver packs in nose. Fuel pump, ECU batt and air valves behind nose bulkhead. Cockpit with pilot,receiver and gyro under cockpit. UAT behind cockpit and 1800 mah afterburner light batt. that I move around to fine tune C/G { currently behind UAT }. I would have to check to see where my C/G is now but the plane flies very well, Nose is very controllable on landing approach. Stabilator's are trimmed up 1/8" which seems to be the norm, no lead in plane.
Scott
Scott
#316

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Joseph- I do not use a UAT. Stopped using those about a decade ago after crashes and deadstick landings due to UAT failures. I find UAT is not needed at all. Just causes problems. That has been my experience anyway. I will add the cockpit later and maybe a pilot. That should make some difference for sure. Thank you for the comments. Terry
#317

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Scott- If you get the chance, check CG and let me know where your at. Maybe you are more like 200 mm. I think I will try that next. First flight just seemed too nose heavy to me. Thanks for sharing. Terry
#318


I will check my C/G within a couple of days. { plane stored in trailer} Mine flew nose heavy also on first flights, moving afterburner light battery helped. so I believe it is behind their range.
Scott
Scott
#322

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I test flew the jet with the CG at 190mm. Mine is at 29lbs with UAT full. For power I have a Swiwin 120. I was worried it was too heavy but it flew pretty good. I have an old version 1 with the glass fiber fuselage not airex. The previous owner put lead shot in the elevator to dynamic balance them which makes me add more weight in the nose. I was told it has never been flown. I am going to replace the elevators to make it lighter and going to reinforce the wing mount in the fuselage as this is a weak point and the have been some that have fail there.
#324

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Yes a friend of mine saw it happen and warned me to take it easy with it. He sent me a picture of the wing so I can see where the weak point is. You can see the area that needs reinforced right where the bulkhead is notched for the engine mount. There is very little support there. I am hoping to have it back together for the war bird event this weekend.
