I converted manual to electric in my RV7A
Last fall I removed the manual trim in my 7A and installed electric trim. Like "Skysailor" suggests here, I put the trim servo itself under the vertical stabilizer on the self located there. I reused part of the old manual cable instead of ordering a custom cable and so far it's working great.
At the same time as I did this swap out, I installed Tosten military style five button grips, and a trim controller board. I purchased the trim controller from Pat Hatch. A trim controller is required when more than one trim switch (I.e. Both grips) are installed.
I'm really glad I converted both my manual aileron and elevator trim systems to electric and swapped out my grips. Trimming the RV has always been easy but now it's truly a no brainer in that I'm just instinctively trimming off pressures. My greatest preinstallation concern was the electrical wiring changes and Pat Hatch graciously guided me via email throughout the process.
I strongly encourage you to contact Pat Hatch for a trim controller and Kevin at Tosten Mfg. They're both great people to work with.
One change I'm thinking about doing (to give me greater peace of mind) is going ahead and ordering from Aircraft Spruce a two foot custom cable to replace the old manual cable I modified. I'm not totally satisfied with my adaptation there.
Jim Harris, RV7A, 2nd owner, N523RM
IO-360, Hartzel CS prop, Older Aerotronics built panel Dual GRT Horizon WS, Garmin 340, 335, Dual 430s, Stratux hard wired to WS, Dynon D10A (backup EFIS)
Retired - Living the dream - And going broke!