Cobri Issues--Help!!
12-12-2005 | 08:57 PM
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From: Warwick,
RI
Cobri Issues--Help!!
Hey Guys,
Alright--- I have a cobri gear box --5.0:1 ratio. I have it installed on myeflite mini edge.
First flight with this gear box was incredibly smooth running a 12X6 SF prop and a tru turn E spinner.
Unfortunately the first landing was a little rough, end result dropping the plane on its nose from about 4 feet.
Upon visual examination everything looked ok until i started to notice a small wobble in the the nose cone. My first thought was well the cobri gearbox shaft in suppossedly un bendable so that cant be it. So i thought it was the tru turn collet. The other thing I noticed is that upon putting full throttle on my Park 400 motor it would start out good and then at full throttle there would be a high pitch whine from the motor and rpm would drop on the prop.
My next though was damn it the motor failed, so I ordered up a brand new himax and installed it tonight. using a new e-collet that high pitch whine is back with my new himax motor. I next thought maybe an esc--tried both motors with 2 different esc's the same whine and loss of rpm/thrust, as if slipping. SO my question is --Have i bent the unbendable shaft?? Is this what is causing the high pitch whine, where at such a high rpm the shaft being bent causes the tooth contact to slip?
What say you guys, right now I'm totally lost.
---Mike
Alright--- I have a cobri gear box --5.0:1 ratio. I have it installed on myeflite mini edge.
First flight with this gear box was incredibly smooth running a 12X6 SF prop and a tru turn E spinner.
Unfortunately the first landing was a little rough, end result dropping the plane on its nose from about 4 feet.
Upon visual examination everything looked ok until i started to notice a small wobble in the the nose cone. My first thought was well the cobri gearbox shaft in suppossedly un bendable so that cant be it. So i thought it was the tru turn collet. The other thing I noticed is that upon putting full throttle on my Park 400 motor it would start out good and then at full throttle there would be a high pitch whine from the motor and rpm would drop on the prop.
My next though was damn it the motor failed, so I ordered up a brand new himax and installed it tonight. using a new e-collet that high pitch whine is back with my new himax motor. I next thought maybe an esc--tried both motors with 2 different esc's the same whine and loss of rpm/thrust, as if slipping. SO my question is --Have i bent the unbendable shaft?? Is this what is causing the high pitch whine, where at such a high rpm the shaft being bent causes the tooth contact to slip?
What say you guys, right now I'm totally lost.
---Mike
12-12-2005 | 09:13 PM
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From: carteret,
NJ
RE: Cobri Issues--Help!!
Most likely you bent the shaft. Maybe you bent the whole gear box if that's possible.
BTW, what kind of amps are you pulling with that gear ratio and prop combo? I'm just curious since I'm going to be getting the cobri GB for my mini edge with the park 400.
Chris
BTW, what kind of amps are you pulling with that gear ratio and prop combo? I'm just curious since I'm going to be getting the cobri GB for my mini edge with the park 400.
Chris
12-13-2005 | 08:43 AM
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From: Clifton Springs,
NY
RE: Cobri Issues--Help!!
Send Jeff a e-flightline an e-mail [email protected] he'll know your answers. If I'm not mistaken, if you bend it you get a replacement for free.
It almost sounds as your spur gear might be slipping. Did you assemble the GB yourself and if so, did you use green locktite when pressing on the spur gear? Also, inspect all the teeth on the spur gear and make sure it doesn't wobble.
I ran my first Katana Mini in nose first from about 20 feet and never bent the shaft on my Cobri.
It almost sounds as your spur gear might be slipping. Did you assemble the GB yourself and if so, did you use green locktite when pressing on the spur gear? Also, inspect all the teeth on the spur gear and make sure it doesn't wobble.
I ran my first Katana Mini in nose first from about 20 feet and never bent the shaft on my Cobri.
