Frustrating 12X Problem
01-21-2010, 11:43 PM
#1
Frustrating 12X Problem
The below 1/9 scale (138") B-17 is almost finished.
I spent the afternoon programming my 12X to it. My fifth big plane on this radio and I thought I had it just about figgered out.
I can't get my tailwheel retract servo to play nice with the rest of the controls.
The plane has three 921 receivers: one for each wing and the fuse. Them main gear are driven by a standard air valve, so the servo travel is pretty small (+20 and -41)
The tailwheel is retracted by a JR791: good, tough servo I have used in several other applications for years, but never with a 2.4GHz system
It simply won't respond to the gear switch UNLESS you give the elevator or rudder lever a little bump. Then it works fine. Both ways. Same need for rudder/elevator bump. I've never seen anything like that!!
I thought maybe the small servo travel for the mains was bothering it, so I did a "Programmed Mix 2" to an auxillary channel. The transmitter "monitor" shows full travel for the auxillary channel, but still the rretract servo will only activate after throwing the gear switch AND bumping the rudder or elevator stick. This is indoors at close range with fluourescent lights and no engines running. I tried a bunch of things like reversing the slave/master assignments on the mix, swapping out receivers....all with the same results.
Help!, please.
Thanks,
mt
I spent the afternoon programming my 12X to it. My fifth big plane on this radio and I thought I had it just about figgered out.
I can't get my tailwheel retract servo to play nice with the rest of the controls.
The plane has three 921 receivers: one for each wing and the fuse. Them main gear are driven by a standard air valve, so the servo travel is pretty small (+20 and -41)
The tailwheel is retracted by a JR791: good, tough servo I have used in several other applications for years, but never with a 2.4GHz system
It simply won't respond to the gear switch UNLESS you give the elevator or rudder lever a little bump. Then it works fine. Both ways. Same need for rudder/elevator bump. I've never seen anything like that!!
I thought maybe the small servo travel for the mains was bothering it, so I did a "Programmed Mix 2" to an auxillary channel. The transmitter "monitor" shows full travel for the auxillary channel, but still the rretract servo will only activate after throwing the gear switch AND bumping the rudder or elevator stick. This is indoors at close range with fluourescent lights and no engines running. I tried a bunch of things like reversing the slave/master assignments on the mix, swapping out receivers....all with the same results.
Help!, please.
Thanks,
mt
01-24-2010, 02:43 PM
#5
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RE: Frustrating 12X Problem
OK, now I REALLY believe you. We hooked the naughty servo up to a 4.8v source and it works like a charm!
Trouble is, there aren't any good servos out there with this kind of power. Futaba sells one with 6v compatibility, but is rated at less than half the torque.
Any ideas on that? Maybe put a voltage regulator on just that servo lead? I'm afraid that would just sit there and waste battery power constantly. Changing the whole fuse to a 4.8v system is an option, but a hybridized pain-to-maintain with everything else at 6v.
Thanks,
mt
Trouble is, there aren't any good servos out there with this kind of power. Futaba sells one with 6v compatibility, but is rated at less than half the torque.
Any ideas on that? Maybe put a voltage regulator on just that servo lead? I'm afraid that would just sit there and waste battery power constantly. Changing the whole fuse to a 4.8v system is an option, but a hybridized pain-to-maintain with everything else at 6v.
Thanks,
mt
01-24-2010, 03:42 PM
#6
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RE: Frustrating 12X Problem
Keep your full system at the 6volt set-up. cut in a small 10amp voltage regulator into an extension (or the one that feeds that servo now) and drop the voltage to the tailwheel retract servo. This will be on the load side of your power switch and will not be powered unless the receiver is energized. The load of the voltage reg itself is negliagable.
-Snuts-
http://www.castlecreations.com/products/ccbec.html
The little 10amp one is the one I like, but I'm sure others are available. I can get these good quality ones from my local hobby shop. Very important to me.
-Snuts-
http://www.castlecreations.com/products/ccbec.html
The little 10amp one is the one I like, but I'm sure others are available. I can get these good quality ones from my local hobby shop. Very important to me.
