08-02-2013, 05:42 PM
Retract Installation
The Big P51 comes with a very nice set of high quality mechanical retracts.
I was looking at using servoless units but these things just looked to good not to use. The only let down was that the heavy duty plywood fastening points in the wings were twisted so I had to do a lot of modifications to the retact flange plates so they would pull down square into the airframe.
When I pulled them into their locations to check the initial operation they were both heavily overloaded due to the torsional stress being applied to the housings by the flange plates. It took a lot of trial and error fitting, checking, removing, modifying and then refitting to get them operating smoothly, at the end of it all I have them operating very smoothly but I am not very happy that an ARF aircraft that cost over $800 has so many build issues that cost hours of my time to rectify.
Anyway here are a few pics. You will see in second pic how much the flange was out when first installed. And the 4th pic shows how much I had to twist the flange to get it to sit right without streesing the housing.
Almost forgot... I'm using Spectrum A7000 retract servos, these big suckers have 18.5 kgs of torque at 4.7 volts and 25kgs at 6 volts. So there is no stopping these bad boys when to hit the switch... they will either close of break the wing in half, but you have to have that sort of power when your retracts weight almost a kilo. Next... tailplane and rudder!
The Big P51 comes with a very nice set of high quality mechanical retracts.
I was looking at using servoless units but these things just looked to good not to use. The only let down was that the heavy duty plywood fastening points in the wings were twisted so I had to do a lot of modifications to the retact flange plates so they would pull down square into the airframe.
When I pulled them into their locations to check the initial operation they were both heavily overloaded due to the torsional stress being applied to the housings by the flange plates. It took a lot of trial and error fitting, checking, removing, modifying and then refitting to get them operating smoothly, at the end of it all I have them operating very smoothly but I am not very happy that an ARF aircraft that cost over $800 has so many build issues that cost hours of my time to rectify.
Anyway here are a few pics. You will see in second pic how much the flange was out when first installed. And the 4th pic shows how much I had to twist the flange to get it to sit right without streesing the housing.
Almost forgot... I'm using Spectrum A7000 retract servos, these big suckers have 18.5 kgs of torque at 4.7 volts and 25kgs at 6 volts. So there is no stopping these bad boys when to hit the switch... they will either close of break the wing in half, but you have to have that sort of power when your retracts weight almost a kilo. Next... tailplane and rudder!
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