il

hey, i just now saw a helicopter on ebay. its a concept 30SX. heres the link. can anyone tell me about this? the windshield is no prob and the blades i think i can fix. other that that, can anyone help? is it a good chopper?etc. etc.
thanks!


http://cgi.ebay.com/ws/eBayISAPI.dll...category=19164

Charlie

That dosen't look like a bad deal, the radio look old. I would be careful what you buy on Ebay, you never know what you are getting. I would send him an email and find out what servos and gyro is in the heli, they could be all old and out dated. If they are it is not that good of a deal. Find out how much fuel has been burnt through the heli, the heli could be worn out.

il

okay ill do that. it says the blades are too long and need to be trimmed. um. huh?

FHHuber

some early helis used longer blades than the new ones. The long blades load the engine and prevent the rotor from achieving its most efficient rpm. It has become relatively common to trim 1 inch off some older heli's blades. (careful... gotta rebalance the rotor)

The glow engines on .30 size helis need to turn 10,000 to 14,000 rpm to be in thier peak power band. If you get a tachometer, and measure the rotor speed, its just a matter of knowng the gear ratio to know the engine rpm. You can find the gear ratio by... marking the clutch bell with a "Sharpie" or other felt pen, count how many times that goes around for one rotation of the main rotor. (Turn the rotor backward... or you might have to turn the clutch bell... auto-rotation system disengagement can drive you nuts trying to turn the rotor never making the clutch move.)