P-51D Mustang 1.2 [Build Notes]
Specifications: (Hobby King)
Wing Span: 1200mm
Flying Weight: 1300g
6 Channel (motor, aileron, elevator, rudder, landing gear, powered canopy)
4 x 9g servo (pre-installed)
Servoless electric retracts (pre-installed)
800kv motor (pre-installed)
30A ESC (Pre-installed)
Powered auto canopy with controller (Pre-installed)
4 blade 10x8 and 2 blade 11x7 prop
Fittings, screwdriver, glue and instruction sheet.
6 Channel RX/TX
2200mAh 3s Lipoly
These are compiled notes/info from various sources, mostly from the great guys from this thread on RCG
NOTES / INFO / IDEAS
Notes: (Various Sources)
- Motor adapter shaft 6.0~6.2mm
- Spinner 74mm. Spinner backplate is keyed. Spinner will need to be trimmed so it does not hit prop and deform it's shape as it is made of very, very thin plastic. Spinner backplate sits about 6mm out from front of cowl, even with the plate keyed on correctly. (Pic#??)
- Supplied lables on wiring - Legend: 1=AIL 2=ELE 3=THR 4=RUD 5=Canopy 6=Gear.
- The plugs for channels 5 and 6 are a tight fit on Spektrum AR6200 RX. I found the easiest way to get plugs in is to start at #6 and work back to #1
- It has been noted in the past that silver paint in some cases can have an adverse effect on the RF signal of the TX/RX so a good quality RX should used with a satellite RX. Though there have no reports of that happening with this plane, that I know of.
- Check that power wiring to Retract/Canopy Control box is not supplied from the factory plugged in reverse polarirty. Even though the board appears to have diode protection, Timmybettle reported his smoked his when it was plugged in.
- The Control Box has a spare output that could used for a nose wheel retract or if no spare channel available could be used to operate the canopy, for example if using all 6 channel because using flaperons, the spare output could be used to open the canopy when the gear is lowered and close it when the gear is raised. This would lessen the chances of over-loading the retract MOSFETS. Although simply 'y' leading the canopy and retracts together will give the same effect. - doh! (Pic#??)
- Retract/Canopy Control Box is powered directly by the battery, not the ESC. So there is no fear of the retracts or canopy overloading the BEC or causing RX 'brown out'. Though a seperate BEC is still recommended for the RX, as no doubt the supplied 40Amp ESC will have cheap MOSFETS in it!
- Retract motors are RF noisy and can interfere with the aileron servo's spiking them and causing them to jitter from mild to crash worthy. I use four different '9 gram' types (pic#??), Hextronic HXT900, Turnigy TG9, Turnigy TGY90S Metal Gear and sometimes retain the 'no-name' servos that come ARF/RTF models. Surprisingly of those 4 types the supplied no-name servos don't get any interference, with the TGY90S being effected the worse, which what I had installed, so I went back to the stock servos and problem solved - I hope. Though I would prefered to use better servos. I think the reason for the interference is because the retract motors dont have any noise suppressing caps combined with the proximity of the aileron and retract servo wires running pressed against each other in the wing. The canopy motor was not interfering with the servos.
- Care should be taken moving the control box around too much, as most of it's wiring is very stiff and will end up breaking off at the PCB. I applied a load more hot glue to where the wires are soldered to the PCB. Only because I was moving the board around a lot during the build. (pic#??)
- Sometimes a retract or the canopy would continue to operate for a few seconds after fully up/down/open/closed. At first I no idea why. The solution for now is to try cylcing them a few times or remove the power and reconnect.
Updated: I'm guessing the controller board detects when the canopy if fully open or closed or the retract fully up or down by getting an overload feedback (or excess power draw) from the motor, when this happens the controller shuts the motor off. The problem with the canopy is it might have a cracked motor holder housing (pic#??) which causes the drive gear to slip on the screw drive when the canopy gets to the closed position causing the controller to never get the signal of an overload condition so it does not know to shut the motor off and continues to drive the motor endlessly. The solution is to remove and repair the cracked housing, however the repair can be rather difficult/fiddily. But it can done, I've done it. Have fun!
- CofG is about 90-100mm back from the wing leading edge where the wing meets the fuselage. Basically near the bottom of the wheel spat/pants when the gear is raised. (pic#?? - Credit: Timmybeetle)
- I'd avoid using the supplied glue, I used a combo of Epoxy, CA and Hot Glue.
- The wings are little difficult to make fully join/butt/mate up, but it can be done with fiddling around getting the strengthening dihedral rod in on the right angle. I got my wings as mated as best I could then clamped. Epoxy was used.(pic#??)
- The tubing in rudder for the tail wheel control wire is too small. This can removed by gently twisting a slightly oversize drill bit into the tube and breaking the grip of the small amount glue that it is tacked in place with then carefully pulling it out. In a similar way to how an 'ezyout' is used to remove bolts that heads have broken off. The tube can then be replaced with an off cut from an old nyrod outer sleeve.
- Control surface hinges should be installed. - TheSelf reported his rudder fell off. As with a lot of EPO planes they do not use hinges on the control surfaces, but simply cut the 'v' in the foam and leave about 1mm uncut to act as the hinge. Over time this is going fail. I might put 'CA' hinges in when any of my control surfaces look like they about to fall apart.
- Aileron servos might not pre-installed, contrary to the note in the specs. At least mine were not. Which means the Black Band around wings has to be cut to run the servo wiring in wing channel/slots/grooves, then clear tape run over where the black band was cut and possibly tape over the entire channel from the servo back to the centre of the wing to hold the wiring in place. Attempts to slide the servo plug and wiring under the Black Band failed, so it had to be cut. (Pic#??)
- Motor tightens up after ESC is powered up, even after power is unplugged the motor still feels tight for a about 15 minutes, almost as if the bearings are seized. But this frees up. A weird effect, no idea what causes that. Some sort of electrical field charged into the windings? Other than that the motor operates fine, but I never trust stock motors to have a very long life span, so that will no doubt be replaced soon.
- Battery compartment needs about a 30mm wide flap cut into the top of it to allow easier insertion and removal of, in my case Nano Tech 220MhA 3S 11.1V or similar Lipo Battery. Also the area behind the battery is going to be cut out to allow more room for the battery wiring to lay in there. (Pic #??)
- I'm going to use a 'plane' (Turngy TG380) gyro on the elevator to lessen the chances of a nose over on bumpy grass runways or in poor windy conditions as I've heard the prop will break even if it 'smells' a prop strike with a foreign object as it's pretty weak! - My thinking on this is if I set the gyro throw high and the motor at high RPM at take off there will be plenty of air flow over the elevator from the prop and it will instantly correct any tenancy for it to nose over. The gyro will only be active when the gear is down because it is 'Y' leaded into the gear channel or I might even change that to canopy channel, so it operates when canopy is open. Although I might ditch the DX6i altogether and put a Turnigy 9X TX modified with FrSky RX and telemetry so that I can have flapperons and everything on separate channels and the gyro turned on and off and adjusted in-flight
- The factory mounted 'servoless' undercarriage has had to be mounted in such a way the the stresses (mainly forward/backward/splat! forces
of hard landings will snap them at the plastic/nylon base elbow. Again, a gyro on the elevator would help (though not help as much as take off due to low air speed and low rpm during landing) here to make every landing a 'greaser' and happy landing!! (pic#?? - Credit: Maverick)
*** This is a draft post. I may be updating it from time to time if required and as news come to hand. ***
*** Or updated at my Club forum 'PEMACFLYERS' http://whlsites.com/forum/index.php
Thanks for a GREAT thread guys - I look forward to more from you!!!