Pilot’s Tosten CS-8 Stick Grip Wiring Completed

I knew wiring the control stick grips would be both tedious and time consuming … and thus far I have not been disappointed. Plus, as always with things like this, it is taking longer than expected.  It also requires quite a bit of bending over … so needless to say, it’s a good way to get a sore back.

Work for the day began by pulling the wiring that will connect both control stick grips together through the seat rib grommets and then adding the pilot push to talk wire and ground wire into the Molex connector on the pilot side.

Pulling in the wires that will run between the two Tosten CS-8 control stick grips.

After the pilot side Molex connector received the pilot push to talk wire and grounding wire, the Molex connector halves were slid together. While looking at the connector and contemplating placing a small wire tie around the connector between the wires to prevent it from opening, I had a great idea. There are spare holes in the Molex connector because only 9 of the 12 of the circuits are in use … so there is already a hole in the connector to run a wire tie through which will prevent the connector from opening. A small wire tie was just ever so slightly too wide, so I ran one edge of the wire tie across the ScotchBrite wheel to shave off just a little material … and presto the perfect connector lock.

Created a connector lock by passing a wire tie through one of the unused holes of the Molex connector. Worked great!

The wire from the control stick grip was given one loop and an existing tooling hole in a seat rib was used to secure the connector onto the seat rib. Have to say, am quite pleased with the way the pilot side grip wiring turned out. The wires and connectors are out of the way of moving parts and the wires have plenty of flexibility for stick movement.

Completed pilot’s side Tosten CS-8 control stick grip wiring.

Moved back to the right side of the RV-12 and crimped the terminals for the Molex connector onto the ends of the wires from the Tosten CS-8 control stick grips. As with the pilot side wiring, the high hat common wire was doubled up with the common wire for the switches ... doing this only requires one ground wire run to the Molex connector. The wires were inserted into the Molex connector body and then dressed with heat shrink tubing.

Stripping wire for the .062" crimp terminals that will be inserted into the Molex connector body.

Completed Molex connector terminating the wires from the co-pilot’s Tosten CS-8 control stick grips.

The last major part of the puzzle to be installed is the wiring that will connect the control stick wiring to the instrument panel. The wires were run through the wire grommets on the co-pilot seat ribs and into the center tunnel. A short cut was taken to avoid the tight grommets in the F-1203A bulkhead by running the wires through the center lightening hole in the F-1203A bulkhead. When the wires get secured with wire ties, they will not rub on the edges of the lightening hole so this should work out well. This was done because the center tunnel grommets in the F-1203A bulkhead are really tight … primarily due to some of the shielded cables making 90 degree bends right after the wire grommets. When this happens the shielded cable tends to pass through the grommet at an angle taking up additional room thus making less room for additional wires.

Feeding the wires that will connect the control stick wiring to the instrument panel through the co-pilot seat rib grommets.

Tosten CS-8 control stick grip wires taking a short cut through the lightening hole in the F-1203A bulkhead to get to the center tunnel and on to the instrument panel.

By this time my back was starting to get a little sore from all the bending over, so decided this was a good point to stop for the day.

Wiring Of Control Stick Grips Begins

Wiring of the Tosten CS-8 control stick grips has begun, but is not completed. However, did get some serious progress made in spite of the late arrival at the hangar. Have been saving this chore until last because I knew it would be both tedious and time consuming. One of the first items tackled was the two Van’s provided wires for the pilot and co-pilot push to talk wires. Van’s has left both these wires rather short … so they are not long enough to make it to where the Molex connector for the stick wiring will be located. Decided on making an extension for those two wires by using male and female pins from a DB style connector and locking the pins together by using heat shrink over the connection. Although not necessary, it is not a bad idea to wear a vinyl glove to keep finger oils off the connector pins when handling them.

DB style connector pins connected together to create an extension for the co-pilot push to talk wire. Heat shrink tubing will cover the extension connectors.

Finished extension for the co-pilot push to talk wire covered with heat shrink tubing to insulate and also keep the pins tightly together.

Having given it considerable thought, decided the easiest way to wire the two Tosten CS-8 grips is to wire all the switches for both grips in parallel … with the exception of the push to talk switches which need to be kept separate between pilot and co-pilot. To accomplish this, a cross cable needs to be fabricated to connect the switches on both stick grips together … but excluding the push to talk wires on both grips. So wire length measurements were taken … keeping in mind allowing enough slack for easy access of the wire stripper and crimping tool. Assembly of the Molex wiring connectors for the Tosten CS-8 stick grips began by cutting wires for the transfer cable and placing a Molex connector on one end of the wires.

Inserting wires into the Molex connector body to complete one end of the transfer cable.

Because the electrical wires for the auto pilot pitch servo run through the wire grommets in the seat ribs on the pilot’s side, the transfer cable being fabricated will run from the pilot’s control stick grip to the co-pilot’s control stick grip. The wires that need to go forward to the instrument panel will tie into the transfer cable at the Molex connector for the co-pilot’s control stick grip and pass through the less crowded wire grommets on the co-pilot’s side and then forward through the center tunnel to the instrument panel.

Crimping gold plated .062" wire terminations onto the ends of the wires coming from the switches on the pilot side Tosten CS-8 control stick grip.

Completed pilot side Molex connector terminating the wires from the Tosten CS-8 control stick grip.

The Molex connector for the pilot’s stick grip mated to the transfer cable. The wires of the transfer cable need to be run through the wire grommets in the seat ribs and over to the Molex connector for the co-pilot stick grip.

Frequent readers of the DOG Aviation Blog may have noted that I’m actually wearing a T-shirt for the first time this year without the need for additional outer wear. The temperatures have finally gotten to the point that it was possible to work in the hangar without needing to wear warm clothes … it is about time!!

Laying Groundwork For Control Grip Wiring

The last grouping of wires yet to be installed in the DOG Aviation RV-12 is the wiring for the switches on the Tosten CS-8 control grips. At this point in time, there will be a few unused switches on the grips , but that will leave the ability to easily add functions down the road … but, truth be told, could easily have gotten by nicely with the Tosten CS-6 grip but they just don’t have the same “cool factor” as the CS-8 grips.

Spent quite a bit of time figuring out how best to run the wires for the switches on the stick grips, taking into consideration free movement of the stick and ease of access for the connectors. Once a good location for the connectors was determined, took the time to make up a wiring chart. Another concern is free space in the wire grommets because they are almost maxed out ... so a test was made by bundling the proper number of 22 gauge wires together to see if there was still enough room to feed the additional wires through the wire grommets. Fortunately, there is barely enough room so it will not be necessary to add additional grommets on the seat ribs. The majority of builders will not find this to be an issue … however, the DOG Aviation RV-12 utilized shielded cables for the strobe and wig-wag lighting which takes up much more room in the wiring grommets.  Free space in the center tunnel grommets is almost non existent, so may need to split the wires between the two grommets in the center tunnel.

For builders interested in the connectors being used, they are a 12 circuit Molex connector. They are the exact same connector as used on the auto pilot servo motor except the DOG Aviation purchasing department ordered them without the unnecessary ears which are for chassis mount applications … also chose to purchase gold plated connector pins for the connectors. All the parts were ordered from Mouser and consist of:

Molex 12 circuit plug PN# 03-06-2122.
Molex 12 circuit receptacle PN# 03-06-1122.
Molex 18-24 gauge gold .062" male pins PN# 02-06-6103.
Molex 18-24 gauge gold .062" female pins PN# 02-06-5103.

Photo of the .062" Molex connector parts, test wire bundles and the 22 gauge wire being used to wire the control stick switches.

Canopy Latch Switch – One Step Forward – One Crunch Back

Today was one of those days at hangar 45 that didn’t work out as planned. The plan was to finish up installation of the micro switch for the canopy latch and complete the wiring for the switch so that item would be totally finished … shy of final adjustment after the canopy is installed. Work began by making up a 5" ground wire with a ring termination at one end and a spade termination at the micro switch end. The canopy switch wire that was previously run through the roll bar up to the instrument panel also received a spade termination so it can be attached to the normally open contact of the micro switch.

Crimping a spade termination onto the 5" wire which will become the ground wire for the micro switch.

The ground wire requires a #19 mounting hole to be drilled in the F-1232A roll bar brace so the ring termination on the 5" ground wire can be attached onto the roll bar brace to obtain an electrical grounding point for the canopy latch electrical circuit. Because the parts have been primed and painted the paint and primer around the hole was removed from the inside face of the F-1232A roll bar brace so a good electrical ground would be obtained. Measurements were taken per the plans and a lead hole was drilled through from the inside of the F-1232A roll bar brace using the angle drill outfitted with a #50 drill bit. The lead hole was then enlarged in steps from the outside to a final size of #19.

Drilling a lead hole through the F-1232A roll bar brace using the angle drill outfitted with a #50 drill bit.

Drilling the mounting hole in the F-1232 roll bar brace for the canopy latch micro switch’s ground wire to final size #19.

Before the micro-switch can be installed, the plans instruct the builder to cut off the roller assembly on the end of the micro switch’s arm. I used a ScotchBrite wheel to grind off the pin for the wheel and then ground off the remaining tangs. The micro switch is mounted via two screws and uses two small nuts under the body of the micro switch as spacers so the micro switch clears the heads of the rivets on the canopy latch plate allowing the switch's body to be pivoted for adjustment.

The canopy latch micro switch prepped and ready for instillation.

Here is where things went terribly wrong … As the micro switch was being screwed into position, it was noticed the bottom screw that goes through the slotted hole in the canopy latch plate was dragging just a little on the upper edge of the slot. The micro switch was removed and placed beside me on the longeron … a small file was rounded up and the inside of the slot was filed slightly larger so the switch could move freely. When stepping back to put the file away, I heard a gut wrenching CRUNCH about the same time I realized there was something under my shoe. Apparently, while filing the slot, my arm must have brushed the micro switch off the longeron and onto the hangar floor so when I stepped back, I stepped on it and completely broke one of the micro switch’s mounting holes. So a new micro switch is on order from Van’s  … fortunately, it is only around $6 so it was not an expensive mistake.

This micro switch did not pass the 200 foot pound test.

Disgusted with myself, decided it was best to call it a day.

Installed Baggage Corner Skin & More Wiring

Learning from the right side, when installing the left F-1273 baggage corner skin made life a little easier by removing even more Clecos from the side skin which made installing the closeout much easier. The loser side skin allowed more play and less friction making alignment and positioning no struggle at all.

Positioning the left F-1273 baggage corner skin so it can be slid under the fuselage’s bottom skin.

The left F-1273 baggage corner skin secured in position with Clecos.

After the F-1273 left baggage corner skin was secured with Clecos, looked ahead in the plans and the next step begins installation of the turtle deck components and rear window … which, if installed at this point in time, will make getting into the tail cone even more difficult than it will be otherwise. So will be hit the brakes on placing more metal on the fuselage for the time being and finish up running wires through the center tunnel then fall back and tidy up all the wiring from the tail cone forward with tire ties.

The only remaining wires needing to be pulled in through the center tunnel are the wires from the switches on the stick grips and the canopy latch switch wire. Decided to knock out the WH-W1114 canopy latch switch wire first … this is the wire that runs from Van’s newly added micro switch for the RV-12’s canopy latch forward to the instrument panel. Note: Some documents also refer to this wire as WH-00109, but one of the newer electrical schematic drawing calls this wire WH-W1114, so that is what I’m going with. Because the conduit for the cockpit lighting is already installed inside the roll bar, could not run this wire through that conduit … so a new conduit was made for the wire by cutting a 30" piece of 1/8" vinyl fuel line to pass through the roll bar. Next the WH-W1114 canopy latch switch wire was run through the center channel wiring conduit and up through the center tunnel to the instrument panel. According to the electrical drawing, at the instrument panel the WH-W1114 canopy latch switch wire will attach to pin 8 of the 37 pin d-sub connector labeled “Fuselage” on the WH-00046 wiring harness.

Feeding the WH-W1114 canopy latch switch wire through the center channel wiring conduit.

The only remaining wires left to run up the center tunnel to the instrument panel are the wires for the switches on the control sticks.  So that will be the focus of the next work session.

Adding More Parts To The Fuselage/Tail Cone

The plan is to hold off on fully riveting the side skins onto the fuselage until after the rudder pedals are installed. The last time the side skins were on the fuselage a test was made to determine if the forward half of the side skins were not Clecoed, could the skins be easily flexed enough to allow access to install the rudder pedal mounting bolts? The hope is to  install the rudder pedals and tighten the fluid fittings without needing to crawl into the cockpit to tighten the hardware. There seemingly was enough room, so will try that tact when mounting the rudder assembly.

In the mean while, there is still plenty to do ... so continued adding parts onto the fuselage/tail cone assembly beginning with the F-1207E-L&R shoulder strap lugs. The lugs attach primarily to the upper skins of the tail cone but also tie into the baggage bulkhead as well. These lugs become the mounting point for the pilot and co-pilot’s safety harnesses and were machine countersunk last year for the flush rivets being used on the DOG Aviation RV-12.

Sliding the left F-1207E shoulder strap lug into the slot in the baggage bulkhead and securing with Clecos. The right shoulder strap can be seen in the foreground secured with Clecos and ready for riveting.

Using the pneumatic rivet puller to rivet the right F-1207E shoulder strap lug onto the top skin of the tail cone with flush rivets.

Decided this would be a perfect time to rivet the F-00062 ADAHRS stiffener in position. This stiffener was not part of the original RV-12 kits. However that has changed ... as Van’s began receiving reports of erratic movement of the ball in the Dynon SkyView turn coordinator and with the help of a couple of builders, Van's isolated the issue. The erratic movement was ultimately traced to prop-wash creating flexing and vibrations of the tail cone’s top skins in the area where the ADAHRS unit is mounted. The fix was to add a stiffener rib part number F-00062 just forward of the ADAHRS unit. This rib makes a HUGE difference in stiffing up the area where the ADAHRS mounts … so builders of older RV-12 kits will want to add this stiffener. I forgot to take a photo of the stiffener after it was riveted in place … but prior to riveting, the F-00062 rib can be seen in its approximate position in the fifth photo on the post dated 4/24/2015.

Riveting the F-00062 ADAHRS stiffener rib onto the upper skins of the tail cone just forward of the Dynon ADAHRS unit.

Prior continuing on mounting left F-1273 baggage corner skins decided it would be a good idea to place a dollop of silicone on the bottom skin to secure the AOA tubing on the bottom skin to keep it well under the flaperon torque tube which will be installed in the future. This needed to be done at this time because the baggage corner skin will close off easy access to this area.

AOA tubing set into a blob of silicone securing the tube to the bottom skin of the fuselage.

While the silicone sets up on the left side of the fuselage, moved over to the right side and began working with the right F-1273 baggage corner skin. The baggage corner skins close out the opening between the side skins and the fuselage’s bottom skin and sit UNDER  BOTH the fuselage side skin and bottom skin ... but OVER the tail cone skin. This skin was a bit challenging because the bottom skin has very little flex because only the outer row of rivet holes is open. The dimples for flush rivets make sliding the skin into position hard because the bottom skin has very little play. The baggage corner skin needs to be slipped up under the side skin about 1/2" higher than its final resting place so the bottom edge of the corner skin parallels the outer edge of the bottom skin ... then it can be slowly worked down and under the bottom skin.

Mike’s creeper came in handy to get under the fuselage to begin working the right F-1273 baggage corner skin under the fuselage’s bottom skin.

After winning the fight with the right corner baggage skin, decided this was a good stopping point for the day.

RV-12's Tail Cone Mated To Fuselage!!

The last few work sessions have been in preparation for the mating of the RV-12's tail cone section onto the fuselage. Having gone off the reservation with regard to installing the electrical along with AOA, pitot and static air tubing plus mounting the Dynon ADAHRS unit into the tail cone prior to mating … there was a small element of concern that perhaps it may have been fool hardy to have done so.

However, I’m glad to report ... YES, it can be done! Although striving to not enter the tail cone at all, at the last moment I decided not to chinch up all the wire ties just in case it was necessary to move tubing or wiring. Ultimately that was not necessary, but probably still a good idea just in case. As such, I will need to extend myself into the tail cone to cinch up and clip the wire ties. Have also decided it may also be wise to add a little extra protection for the wires where the wiring bundle makes the bend aft from the backside of the F-1206A bulkhead onto the J channel on the left side of the tail cone. Don’t want vibrations to cause the edge of the J channel to chafe the wiring. So even though I will still need to reach into the tail cone, cinching and clipping the wire ties should be, for the most, part an easy task.

Mating the RV-12’s tail cone to the fuselage was an all hands on deck event. There were four of us … that seemed to be the perfect number. Jan (who is the only one of us that has been working out regularly in a gym) was given the task of holding and maneuvering the aft end of the tail cone.  Mike T. and myself stood on either side of the forward end of the tail cone to support and maneuver it into position. Mike K. went from side to side to flex the skins during mating, he also verified the skin overlaps were correct and the holes were aligning correctly. One good thing about the DOG Aviation RV-12 having dimpled rivet holes is when the dimples finally seated in place, the holes were, for the most part, instantly aligned.

Mating the tail cone was an all hands on deck event. Jan holding the tail cone, Mike K. installing a Cleco, me working on the bottom skin and Mike T. on the far side of the tail cone.

Total time at the hangar was about 45 minutes much of which was spent devising a plan of attack, rounding up Cleco pliers, clecos and a couple of hole alignment tools. We took our time and the actual mating process didn’t take very long ... perhaps 20 minutes or so. Jan, to her credit, was a real trooper because she had the most taxing job of holding the tail cone the entire time and only started getting tired of holding it as the final few Clecos were being installed. She reports she can feel the burn today.

After getting the RV-12’s tail cone mated to the fuselage, we left the hangar and celebrated the event over lunch and a few effervescent adult beverages. Having worked on the RV-12 until after midnight the night prior, was not too eager to return to the hangar to continue on. So took the rest of the day off and did not feel guilty because major progress was made.