1.7 Hours -
My electric elevator trim kit finally arrived last night and I was anxious to get into the garage to install it. However, I was still confused by the plans (or lack there of). When I get stuck, I consult multiple on-line sources, primarily consisting of the forums at vansairforce.net and several builder’s sites. As usual, I was slightly relieved to find that many builders have had problems at this stage.
The first problem is finding dimensions on the plans. They were well hidden, but I managed to find them. The second problem is that many builder’s find the listed dimensions to be wrong. Following the dimensions in the plans will often result in the trim servo being mounted off center. The third problem is getting the servo to fit in it’s brackets without having to fabricate a spacer. Thanks to Brad Oliver’s build site, my servo didn’t need spacers.
The electric trim kit contains a servo, switch, position indicator, and associated hardware. Van’s also throws in the z-brackets that are used to attach the servo to the trim access cover, new control horns that don’t require trimming, and a bag of assorted hardware.
The electric trim kit contains a servo, switch, indicator, and associated hardware.
The trim servo is small and light.
The kit also included two z-brackets for attaching the servo to the trim access cover.
First off, I needed to find the dimensions for marking the trim access cover for proper alignment of the z-brackets. Once I located these on the plans, I drew corresponding lines on the access cover. I then clecoed the servo to the z-brackets and lined up the assembly with the marks on the access cover. As with many other builders, I found that following the plans would leave the servo out of alignment. In order to center the servo, I found that I needed to move it over a mere 3/16ths of an inch.
Following the dimensions given in the plans, the servo was slightly off center.
After moving the z-brackets over about 3/16", the servo lined up correctly.
Once everything lined up, I clamped the z-brackets in place and used them as a template for match drilling the trim access cover. Then, I deburred and dimpled the access cover and z-brackets. In order to properly seat the servo without spacers, I countersunk the two aft z-bracket attach holes for NAS1097 rivets rather than dimple them. By countersinking these holes, the shop head of the rivet will sit slightly lower than it would in a dimpled hole. NAS1097 rivets are used because the access plate is not thick enough to accept a standard countersink. The other four z-bracket attach holes were dimpled for standard rivets. (Thanks again to Brad Oliver’s build site for this tip.)
After getting everything lined up, I drilled the z-brackets to the cover plate. You can see the original line per the plans and my line, where I actually installed the brackets.
The trim access plate was dimpled before priming. I choose to use NAS1097 in the two aft holes per Brad Oliver's build site.
After everything was dimpled, I primed everything and then riveted the assembly together. The servo fit and alignment was perfect.
Primed, riveted and ready to be installed. I need a 9V battery so I can test it.
Finally, I switched gears and worked on the trim tab a bit more and final/match drilled the control arms to the tab. The next step in the trim tab is to start attaching the hinge and the plans had me thoroughly confused, so I decided to call it a day.
The control arms were drilled to the trim tab.
