Twin Engine question
01-14-2010, 10:41 AM
#1
Twin Engine question
I'm new to electrics, but have been flying for years, however, that seems to not help in this case.
I've always avoided twins with gas/ nitro as I thought wellm, If one engine dies, often the plane has terrible yaw characteristcs and unless, swift throttle / rudder management happens, the plane may be doomed.
Now that electrics are proving to be a real viable way to fly RC these days, I broke down and now have several planes ranging from a PZ Me109, HL P-47, Bananna EDF jets. So given my meager electric experience with those RTF type planes, I finally purchased a twin engine ARF, thinking Electrics would be the way to go to avoid an engine out problem, but I have several questions which I haven't been able to find the answer to. They are:
1).prop size based on motor and ESC combo
2).Should props be counter rotating ?
3).What battery size ?
The plane is a Graupner He111, 68" W.S., weight~6.5pounds
2 turnigy 35 size electric motors
2 sentry 60amp speed controllers w/ BEC
I plan to run both sets of power wires to a single "t" type fitting to hook them to 1 battery.
I figured both ESC's could connect to a "y" haness and into the throttle plug of my 2.4ghz receiver.
If the engines should run counter-rotating, I don't see that as a problem, I can switch the wiring, but don't know if they should. Instructions don't suggest anything.
If they run the same direction, I expect more lt torgue and p-factor
In that scenario, I'd like to use the parkzone 3 blade 9x7 props (designed for the PZ Me109) for scale looks, but I'm afraid I don't know enough to keep from burning something out .
Any suggestions?
I've always avoided twins with gas/ nitro as I thought wellm, If one engine dies, often the plane has terrible yaw characteristcs and unless, swift throttle / rudder management happens, the plane may be doomed.
Now that electrics are proving to be a real viable way to fly RC these days, I broke down and now have several planes ranging from a PZ Me109, HL P-47, Bananna EDF jets. So given my meager electric experience with those RTF type planes, I finally purchased a twin engine ARF, thinking Electrics would be the way to go to avoid an engine out problem, but I have several questions which I haven't been able to find the answer to. They are:
1).prop size based on motor and ESC combo
2).Should props be counter rotating ?
3).What battery size ?
The plane is a Graupner He111, 68" W.S., weight~6.5pounds
2 turnigy 35 size electric motors
2 sentry 60amp speed controllers w/ BEC
I plan to run both sets of power wires to a single "t" type fitting to hook them to 1 battery.
I figured both ESC's could connect to a "y" haness and into the throttle plug of my 2.4ghz receiver.
If the engines should run counter-rotating, I don't see that as a problem, I can switch the wiring, but don't know if they should. Instructions don't suggest anything.
If they run the same direction, I expect more lt torgue and p-factor
In that scenario, I'd like to use the parkzone 3 blade 9x7 props (designed for the PZ Me109) for scale looks, but I'm afraid I don't know enough to keep from burning something out .
Any suggestions?
01-14-2010, 07:37 PM
#2
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RE: Twin Engine question
If you can find 'em counter-rotating might be better... but probably no biggee. Turnigy 3530 with Kv suited to 9x7x3 props should be okay.... 300W per motor.... can they cope with that much? Each pack needs to be able to cope easily with that 300W (?30A minimum).
