Dynon SV32 Autopilot Roll Servo Installed

Continuing with the punch list of to do items prior to mating the tail cone with the fuselage brought me to the autopilot roll servo. The Dynon SV32 autopilot roll servo would be much easier to install now while access is still good.

Dynon SV32 autopilot servo motor … this one will be used for roll control.

Before the SV32 servo can be installed, the wires coming out of it require some attention. First the wires from the SV32 servo motor need to be cut down to 7" and female .093 Molex connector pins need to be crimped onto the ends of the wires .... then inserted into a 9 pin Molex connector body. Also, two pushrods need to be fabricated and adjusted lengths of 5 1/4" and 6 1/4 " they will be used for the roll and pitch servos respectfully.

Dynon SV32 servo and parts to make up the roll and pitch pushrods.

The .093" Molex connector pins that came with the autopilot servo kit are a little harder to work with than usual. Instead of being individual connector pins they are on a long strip and the individual pins need to be cut out from the strip.  These strips are usually used in assembly line machines … preparing individual pins from these strips requires a couple of extra steps prior to crimping the pins. For builders not familiar with working with these pins, I hope you find the following helpful in preparing the pins for use.

Strip of .093" female Molex connector pins prior to separation.

Separate the pins from the strip by cutting through the eyelets between the pins using wire cutters.

Separated Molex connector pins ready for final trimming.

After all the pins have been separated from one another, use a pair of wire cutters to remove the remaining portions of the eyelet …. This should leave you with pins having two tabs or “wings” coming out from each side of the pin.

Trimming off all the eyelet material from the pins with side cutters to create tabs or “wings”.

After removing the eyelet material, the tabs should look like the ones in this photo.

The next step is to bend both tabs up with pliers to match the shape of the “U” the wire will sit in before being crimped. I find that bending each tab upward a little first with pliers … followed by squeezing the entire pin with pliers to finish bending the tabs upward, results in nicely forming the tabs into a “U”.

Bending the tab on the connector up a little with pliers to get the bend started.

Finished Molex .093" connector pin after being squeezed with pliers to form the tabs into a “U”.

Pin on the left is finished  and ready for crimping … pin on right still has the tabs or “wings”.

When crimping small diameter wire such as the 22 gauge wire Dynon used on the SV32 servo motor, I like to strip the wire twice as long as usual and fold it back on itself prior to inserting the wire into the connector pin. I find this method insures very tight crimps when using small diameter wires with Molex connector pins.

One of the servo wires stripped twice as long as necessary … approximately the length of the “U” on the connector pin. This bare wire will be twisted tight and folded back on itself and inserted in the connector pin for crimping.

Using a Tool Aid crimping tool with appropriate dies to crimp the .093" female Molex pins onto the SV32 servo wires.

After crimping the connectors, I used a hand crimping tool to tweak the strain relief area on the connector pins then inserted them into the nine pin Molex connector block. (Used the yellow handle tool just above the red handled wire strippers in the above photo).

Finished … now all the servo motor wires have .093" female Molex connectors attached to them and are ready to be inserted into the nine pin connector body.

Now that the Dynon SV32 roll servo motor is ready for instillation, the instructions call for attaching the fabricated F1291 pushrod into the middle hole in the SV23 servo arm. Next the whole assembly is attached to the fuselage with four bolts along with some blue Loctite 242 and the Molex connector is secured to the body of the servo motor with a wire tie.

Using a torque wrench to tighten the F-1291 push rod hardware on servo arm.

Tightening the mounting bolts for the Dynon SV32 auto pilot roll servo motor with a torque wrench to finish the install.

WD-1213 Flap Handle Installed

Now having a bracket to secure the static line to the flap handle block decided to go ahead and mount the flap handle assembly into the center tunnel. However, will hold off on installing the flaperon mixer assembly because the flaperon mixer assembly and associated push tubes will result in a significant loss of center tunnel access. Therefore decided it best to just install the flap handle assembly at this time. Good center tunnel access will be needed as the tail cone is moved closer to the fuselage and finally mated, because the pitot & static lines along with the trim motor cable will need to be migrated forward towards the instrument panel to take up the slack. Once that happens the center tunnel cables will need to be secured with wire ties and the hold down straps.

Setting the flap handle and flap handle mounting blocks in place.

WD-1213 flap handle installed.

Modifying F00050 Bracket For Extra Static Line

RV-12 builders not running a static line to the instrument panel for backup instruments can  ignore this post.  As I was about to install the flap handle assembly, I spotted a potential problem with the extra static line I ran through the center tunnel for the backup instruments.  Van’s is now supplying the F-00050 wire routing bracket which is really a “shoe” that presses down on the wires, preventing them from chafing on the moving flap handle assembly. If the static line were run down and under the F-00050 bracket it would require making a radical downward bend right at the center channel bulkhead grommet … which, I fear, over time may pinch off the static tube. I placed the flap handle block assembly with the F-00050 routing bracket attached in the general vicinity of where it will be permanently mounted to get a visual.

One can easily see the static line in my hand would need to take a radical downward bend at the grommet to squeeze under the F-00050 wire routing bracket.

Holding the static line in my hand gave me an idea. I did receive one extra F-00050 bracket … one came in the finishing kit when I ordered the ADSB option, the other another bracket came with the avionics kit. The idea is to repurpose the extra F-00050 bracket and use it to keep the static line on top of the  black flap handle block … so I searched for hours and finally found the spare F-00050 bracket. (One of the bad things about packing up everything and moving the RV-12 project to the airport is remembering where things were salted away for the move).

Looks like the spare F-00050 bracket will do a good job keeping the static line out of harms way.

Because the bracket is designed to go down instead of up, new mounting holes need to be drilled. After two new mounting holes were drilled, all excess material was cut off on the band saw.

The band saw was used to remove the old mounting holes and also remove some material from the shoe as well.

Finished modification of the spare F-00050 bracket to hold the extra static line.

The following photo shows what the finished assembly will accomplish … the parts are not bolted, they are just sitting in the general area they will reside (actually needs to be more aft). Feel the modified F-00050 bracket for the static line turned out great and should work quite well.

The left flap handle block with both F-00050 brackets attached. With this setup the static line will not need to make a radical bend to get under the “shoe”.

Modifying F-1231F Latch Plate For A Micro Switch

Whittling down on the punch list of things that will be easier to do prior to mating the tail cone brought me to the Van’s notification dated 14-05-22 which entails adding a micro switch onto the canopy latch plate. The DOG Aviation procurement department ordered all the necessary items minus the micro switch … there was already one left over from the stall warning modification where a micro switch with a slightly longer arm was used in place of the Van’s supplied micro switch. The micro switch used for the canopy latch is the same micro switch that Van’s uses for the stall warning.

The F-1231F-1 latch plate is the new replacement for the existing F-1231F latch plate.  RV-12 builders that used solid rivets to attach the latch plate to the roll bar assembly may want to consider utilizing the method described below to modify the existing latch plate to accept the micro switch.

Because solid rivets were used to build the roll bar/latch plate assembly, I was not too keen on drilling out the four solid rivets securing the latch plate onto the roll bar assembly and was hopeful the new latch plate could be used as a drill template.  The two parts look identical except for the addition of two mounting holes for the micro switch and an additional mounting hole for the C-1214 latch block.

Existing F-1231F latch plate riveted onto the roll bar assembly.

Replacement F-1231F-1 latch plate with three additional holes.

To verify that the existing F-1231 latch plate could be modified in place, a red dot was placed onto the heads of all four rivets securing it onto the roll bar. The new F-1232F-1 latch plate was Clecoed on top of the latch plate. Washers the same height as AN470AD4 rivet heads were used to square up the assembly.

The washers placed between the two latch plates will allow the plates to sit square on top of one another when secured with Clecos using the two latch block mounting holes.

After the new latch plate was Clecoed on top of the existing latch plate, the red dots placed on the rivet heads were verified to be centered in the holes (no adjustment was necessary). Using the new latch plate as a guide, the small hole in the F-1231F-1 was drilled using a #43 drill bit … this hole is tapped later using a  #4-40  tap. The crescent slot was created by drilling two #30 holes and using the drill bit to remove the thin center area in-between the two holes, completing the crescent shape. Lastly the additional hole on the bottom of the latch plate was drilled to #30.

Drilling the #43 hole which will become the pivot point for the micro switch after being tapped to 4-40.

Drilling the two #30 holes that become the micro switch adjustment slot.

Latch plate after drilling. The slot still requires a little bit of filing to smooth it out.

The next step was to deburr all the newly created holes and file the slot smooth followed by tapping the #43 hole for #4-40 threads. A screwdriver style tap holder was used with good results.

Tapping the #43 hole for 4-40 threads.

Once the threads were tapped into the F-1231F canopy latch, it has now become transformed into a F-1231F-1 canopy latch and ready to accept the micro switch assembly.

Trial fit of the micro switch. All is well and there is a free range of motion from one side of the slot to the other.

The only part of the two latch plates that differed slightly was at the very tip of the latch ... the new latch plate is just slightly shorter as can be seen looking at the red markings in the previous photo. I seriously doubt this will be an issue, but marked it just the same … so if material needs to be removed by a few strokes of a file, it is marked.

WD-1216 Pushrod Secured To WD-1213 Flap Handle

Now that the flap handle has returned from powder coating, decided to work on the controls a little more. The one end of the WD-1216 pushrod attaches onto the WD-1213 flap handle and the other end receives a CM-4M rod-end bearing. The plans call for adjusting the length from the flap handle body to the centerline of the CM-4M rod-end bearing to 11 25/32".

Measuring 11 25/32" from the body of the flap handle to the center of the CM-4M rod-end bearing.

Found it easier to slide a bolt through the CM-4M rod-end bearing and place a line on a piece of paper so the bolt could be visually kept square for the measurement.

Completed pushrod/flap handle assembly. A piece of paper with a line drawn on it was used as an aid to keep the CM-4M rod-end bearing square while obtaining the proper length measurement.

After the correct measurement was obtained, the parts were secured with jam nuts and a drop of blue Loctite.