Elevator trim servo assembly [3.0 hours]

I put together the trim servo assembly and attached the cables. I haven’t decided what type of electrical connector to use, so for now I temporarily dangled an RJ-45 connector off the five Ray Allen servo wires. After a bit of juggling I was able to feed the two trim cables through the horizontal stabilizer bushings, the elevator bushing, and out the inspection cover hole on the bottom of the elevators. I marked where, on the read deck flange, some material will need to be ground off in order to accommodate the cables.

Having done that, there was no way to screw on the elevator inspection covers, per the plans. I recall reading about this anomaly – one of the few times where Van’s plans lead the builder astray – but for some reason I had still blindly followed the instructions and riveted the WD-415 cable attachment brackets to the inspection plates per page 9-15 step 7.  I drilled out the inspection plate rivets, removed the attachment brackets, and threaded these onto the cables seperately. Then I simply cleco’d the inspection plates back in place. I know some people pop rivet these on during final assembly, meaning they have to be drilled out if (when) the trim cables have to be replaced. Not really a bad solution, replacement parts from Van’s only cost a few dollars.

I set up the trim adjustments, without being too fussy since it all comes apart again. The video is correct – the left trim tab does not travel “up” beyond the trailing position, only the right tab does.

  • empattach30
    Trim servo assembly, with temporary cabling, ready for trial assembly
  • empattach31
    Temporary trim control!
  • empattach32
    Trim servo assembly trial fit. Rear deck flange will need some trimming after disassembly, to accommodate the trim cables.
  • empattach33
    Trial fit of trim cable to trim tabs.