Tankerpilot75
Well Known Member
I have the opportunity to purchase a TruTrak automatic pitch trim module at a very reasonable price (lunch) for my Vizion 385 from a friend who chose not to make it part of his autopilot installation (he has manual trim).
Two years ago I converted my RV7A from manual trim to electric and installed Pat Hatch?s Ultimate Trim Module board under the copilot?s seat (I love this trim hub board and Pat stepped through the installation with great patience). At times (when climbing/descending) I would appreciate automatic pitch trim capabilities for airspeed changes.
However, I?m honestly more than a little concerned about the wiring changes required and the placement of the module. If I?ve read through the installation instructions correctly, the module must be installed flat. I have literally very little space available behind my panel, a little under the pilot seats, and if I install the module behind my cargo panel near the elevator servo then a very long set of wires is required to connect the module to the autopilot control head and would require me to drill a new hole through my wing spar to run these wires to my autopilot control head.
I?m not even sure how this module works. Normally I would expect it to send commands to the elevator electric trim (which I installed on the self below the vertical stabilizer and use a push/pull cable to transmit trim changes to the elevator trim tab). But looking at the installation instructions I almost think it actually moves the autopilot elevator servo which I think would aggravate an out of trim condition.
Can someone explain to me how this auto trim module works and does anyone make a conversion cable for this module installation? I?m really reluctant to mess with my electric trim system because it was such a challenge for me to install it and get all the other stick buttons to work correctly. I may be trying to make my little RV more complex then it really needs to be. After all, it?s not a jet.
Advice sought!
Two years ago I converted my RV7A from manual trim to electric and installed Pat Hatch?s Ultimate Trim Module board under the copilot?s seat (I love this trim hub board and Pat stepped through the installation with great patience). At times (when climbing/descending) I would appreciate automatic pitch trim capabilities for airspeed changes.
However, I?m honestly more than a little concerned about the wiring changes required and the placement of the module. If I?ve read through the installation instructions correctly, the module must be installed flat. I have literally very little space available behind my panel, a little under the pilot seats, and if I install the module behind my cargo panel near the elevator servo then a very long set of wires is required to connect the module to the autopilot control head and would require me to drill a new hole through my wing spar to run these wires to my autopilot control head.
I?m not even sure how this module works. Normally I would expect it to send commands to the elevator electric trim (which I installed on the self below the vertical stabilizer and use a push/pull cable to transmit trim changes to the elevator trim tab). But looking at the installation instructions I almost think it actually moves the autopilot elevator servo which I think would aggravate an out of trim condition.
Can someone explain to me how this auto trim module works and does anyone make a conversion cable for this module installation? I?m really reluctant to mess with my electric trim system because it was such a challenge for me to install it and get all the other stick buttons to work correctly. I may be trying to make my little RV more complex then it really needs to be. After all, it?s not a jet.
Advice sought!