Finally! My MGL autopilot servos are permanently installed in my Bede BD-4C airplane. In my last post, Mounting Autopilot Servos in the BD-4C (Really), I included photos of the roll servo, mounted underneath the right rear passenger’s knee. The pitch servo is aft of the baggage compartment and connected to the middle of the push-pull rod for the horizontal stabilator. Here are photos of the mount before I attached the servo (click on any photo to see a larger version).
And… you’re right… there is an extra set of holes in the mount. Either I drilled the first set in the wrong place or those are lightening holes. I vote for lightening holes!
Here is a photo with the autopilot pitch servo and the actuator arm installed.
The autopilot roll servo installation worked out well, too.
The MGL servos come with travel-limiting bolts, to avoid any possibility that the control arm could move to “over center” and lock up. I tested both servos at full control deflections in all directions to assure that the control arms do not prematurely hit the bolts. Here are photos of the roll servo:
I repeated the tests for the pitch servo and there was much more room. The control arm does not swing anywhere near as much. The tricky part for the pitch servo was clearance at the end of the actuator rod where it connects to the push-pull rod.
Now I am working on building a shelf to hold the MGL SP-6 magnetometer. This is much easier than the autopilot servos since it is both light and does not have to resist any torque. I used my trusty ol’ Boy Scout compass to check and found a spot that is free of magnetic interference, even from the magnets in the pitch servo motor. There is an aluminum angle already in place to hold one side of the shelf. I mocked up a second angle and a shelf to see if it all comes together and I think this will work.
What do you think?
Very professional! I agree with the “lightening” holes! The FAA once saw a 1/4 in hole in a panel on the first BD-4 we built. We had a potentiometer mounted but changed our mind. The inspector asked what that was and Jim Tinsman said it’s a lightening hole. The agent gave Jim a “look” and said mark it “INOP”.
“As an FAA inspector, I’m not happy ’til you’re not happy.”
Nice work Art. I just came back yesterday from 5 days of building the BD4 C at BD south east. Thanks to the generous crew ( Jeff Bede, Tim Becker, Steve Horton and Steve from Medina OH who made the building process easier. I hope to see more pictures of your BD4 C.