extra 300

My Feedback: (3)

i am trying to get away from pneumatic systems but still not set as to which servos should i use to actuate gear doors,
what specs (torque, movement amplitude, size....) should they have and what would be the correct setup to install them to achieve a large amplitude/ movement especially on an F-16 type of main gear doors.
Should servo also swing (same as actuator when deploying?) if this is the case how could this be done?

Appreciate all info you can share.
Thanks

rcmigpilot

My Feedback: (26)

What you need will depend on what size plane you have. A good mini servo will work on a 1/8-1/9 scale, for a 1/7 and bigger you'll want a full size servo. The movement of the door will rely on the length of the servo arm and the placement of the attachment on the door, the closer to the hinge the less servo movement required, but the more servo torque needed. The ideal setup would use a ball link at the servo and have the pushrod on the opposite side of the servo from the door with the pushrod in line with the arm so when the doors are closed the weight of the door is pulling on the linkage and isn't held up by the servo motor. If you have room a linear actuator would be the way to go, attachment would be similar to the air cylinders and you can control the throw just like a servo. I swapped out one of these for the air cylinder on the speed brake on my AD Scorpion and it worked great.

https://www.actuonix.com/linear-serv...=XIDSC82|AAYS6

invertmast

My Feedback: (23)

The electron linear actuators work very well for gear doors.

bidrseed2

My Feedback: (2)

Have you actually used these?
I thought their travel stroke was fixed, so you can’t accurately set open and close limits.
You can set one such as the gear closed position, but for the open position you’re at the mercy of the size of horns on the door.

FlyJ

That’s not the case for Actuonix actuators. Actuonix actuators are PWM controlled like a servo and have variable end points. I’ve used them many times.

invertmast

My Feedback: (23)

i use them on the main wheel doors on my T-38. Setting the proper location (in relation to the door hinge axis) of the actuator attachment is the key to setting them up properly, you cant just bolt then to a door hinge. They work very well and arent full of plastic parts like the actuonix ones. The other issue about the actuonix ones i dont like is they slow down the closer they get to their end point location (when using “RC” versions) and the repeatability of them stopping in the same place quickly is pitiful.

extra 300

My Feedback: (3)

Thank you for your different inputs, actually i prefer to focus on servo solutions as believe it would be a more affordable solution.
Presume servos should have metal gears, Regarding torque what would be a minimum requirement for a 1/9 or 1/8 scale model?
Let's say for an F-16 type of gear doors which are quite large (the mains) and require lots of movement.

acw

My Feedback: (1)

I like to use glider wing servos for gear doors. For example: https://www.mksservosusa.com/home.php?cat=8&page=1

Most of them mount flat which makes installation very easy.

invertmast

My Feedback: (23)

torque is less important than linkage setup imo.

the door is under the most load trying to keep the door shut since the insides of our models arent sealed like most full scale airplanes. Having the linkage attachment point, servo arm screw and the servo arm linkage attach point all in a row to “over center” the door when it is Closed is the most important thing to do. This sets it up so that the servo torque isnt used to hold the door shut, but only to hold the arm in position.

ive been using Mini-size servo’s with great success. With a large door like a F-16, more torque wont be a bad thing.

extra 300

My Feedback: (3)

Thanks for the advice. in fact i have hitech 5125 glider wings servos, kind of old generation but could be programmed separately even without the use of TX.

extra 300

My Feedback: (3)

I understand the concept but still trying to figure out what you are describing. i guess if you have a photo or can point out a short video of an example, it would be much appreciated.
Thanks