F-1202Y Strut Attach Angles Match Drilled

Short work session today but managed to make more forward progress by way of match drilling both the F-1202Y strut attach angles.  The strut attach angles were riveted onto the F-1202H-L&R canopy ribs many weeks ago and now that the top of the longerons were drilled for the panel base, those holes are now used to match drill the F-1202Y strut attach angle. The F-1202H-L&R canopy ribs were secured onto the panel base with Clecos so that two holes could be match drilled into the F-1202Y strut attach angles.

F-1202H-L canopy rib Clecoed in place so the F-1202Y strut attach angle can receive two holes there my fingers are pointing.

 Match drilling the F-1202Y strut attach angle to the recently drilled holes in the left longeron.

After the F-1202Y strut attach angle on the left side was match drilled, the F-1202Y on the right side was match drilled in the same fashion. The assemblies were then removed for deburring.

Longerons Matched Drilled To Panel Base

The original task for the day was match drilling the top of the longerons to the F-1202B panel base. Before getting involved with the drilling, the plans were closely scrutinized because a small issue caught my eye regarding the F-1201B firewall shelf. The page of the plans calling for the match drilling of the panel base to the longerons also has a detail showing the mounting of the F1295-L&R stiffeners. Close inspection of the detail revealed a small issue … four rivets would need to be drilled out to install the F-1295-L&R stiffeners. Thinking I may have made yet another screw-up, paged back through the plans to the page that calls for the riveting of the F-1201B firewall shelf to have a look. The plans made no mention of leaving those four rivet holes open. There was mention of leaving holes in the firewall shelf open … just not the holes in question.

My fingers are pointing to the two rivets which need to be drilled out … this will allow the F-1295-R stiffener to be riveted to the underside of the F-1201B firewall shelf.

One can see all six rivet holes in the F-1295-R stiffener that need to attach to the underside of the F-1201B firewall shelf.

I believe this is a case where the F-1295-L&R stiffeners were added later to the RV-12 kit and the wording in the instructions had not caught up yet. Sure glad I discovered this prior to having the side skins installed, otherwise it would have been much tougher to remove the two offending rivets on each side of the F-1201B firewall shelf. As it was, the two rivets closest to the upper firewall posed a bit of a challenge because the rivets were so close to the upper firewall that the body of the drill prevented a straight shot at the rivets. Ended up using a 12" drill bit to drill out the two rivets closest to the upper firewall.

Flexing a 12" drill bit to get a reasonably straight shot at the head of the rivet so it could be drilled out.

Right side of the F-1201B firewall shelf after the two rivets were removed. The outermost row of rivet holes needs to be open like this on each end of the F-1201B firewall shelf to allow instillation of the F-1295-L&R stiffeners.

After correcting the above issue, work began on match drilling the F-1202B panel base to the top of the longerons. Following the instructions, the outer edge of the longerons were aligned with the edge of the F-1202B panel base and clamped in position for match drilling.

Match drilling #30 the F-1202B panel base to the right longeron.

Once the right longeron was match drilled to the panel base, the same procedure was used to match drill the left longeron. After both longerons were match drilled to the F-1202B panel base, the Clecos were removed and the parts were deburred.

Finished match drilling of the F-1202B panel base to the left and right longerons.

Shielded Cable Grounding Completed

Had a short session in the shop but was able to finish up the grounding of the shielded cables used for the nav/strobe & wig-wag wiring. A butt splice was used to connect all the ground wires together to a single ground point on one of the inboard seat ribs. The ground wires are a little long … but that made it easier to crimp the butt splice and the ring terminal. After the connector crimping was completed, the ring terminal was connected to the ground point on the inboard rib. Also, the stick grip and spare ground wires assemblies made yesterday were connected to the ground point on the inboard seat ribs. Once all the wiring was in place and connected, the wires were dressed with cable ties.

 

The shielded cable's ground wires all dressed with cable ties.

The other item completed in today’s shop session was finishing up connecting the ground wire to the +12 power outlet and dressing the power outlet’s wires and auxiliary audio cables with wire ties. Van's suggests securing the auxiliary audio connector to the top of the power outlet with a wire tie so that is what was done.

Auxiliary audio wires and power outlet wires dressed with wire ties.

Tying Down Some Lose Ends - Wires

Thought today would be a good time for tying down some lose ends - wiring. The accessory power socket still required a +12 volt wire connection, along with the accompanying ground wire which attaches to the ground point on the inboard seat rib.  Another lose item that required attention is the termination of all the ground wires from the shielded cables used for the strobe and wig-wag lighting.  The current plan is to group the grounds for the shielded cables together using a butt splice and run a single wire from the butt splice to the ground point on the inboard ribs.

Connecting the +12volt wire to the accessory power socket after a female spade connector was crimped onto the end of the wire.

While about to attach the accessory power socket’s ground wire to the ground point, it occurred to me I’ll need yet another ground wire for the switches in the control stick grips that were procured at Oshkosh. So not knowing if there will be a need for additional grounds down the road, decided to crimp two wires together in a ring connector so if something comes up that needs to be tied to a ground point, there will be a spare ground wire available on each side of the fuselage to do so. A contributing reason for doing this is although the ground point on the seat rib looks accessible, trying to attach the multiple ground ring terminals while holding the screw of the Adel clamp, then placing on the screw and threading the nut in place using only finger tips is difficult.

The ring connector that has the two ground wires and the ring connector for a shielded cable ground need to join the ground wire seen on the Adel clamp.

Sadly, I did not finish the job of tying down all the grounds. By the time I got to this point, the shop was very hot and humid so I decided it would be best to work on it in the morning.

Righting The Wrong – RV-12 Seatbacks Installed

After giving the botched F-1237E hinge debacle considerable thought, an action plan was formulated to correct my failure to remove the center eyelets on the hinges. All the rivets holding the hinges in place could have been drilled out so the hinges could be removed … but that choice was deemed to be an “if all else fails option”. Reason being, I wanted to make sure ALL the rivet pieces could be collected and not left to rattle around inside the fuselage. Because hand access to some of the internal ribs are now essentially closed off - drilling out all of the hinge rivets would have been problematic when it comes to retrieving all the parts.

After a lot of brainstorming, decided to do some practice cuts on scrap material for proof of concept testing. All went well so it was time to put the plan in motion. Figured I could remove the two rivets in the area where the eyelets need to be removed. Collecting all the rivet pieces proved to be a very time consuming and challenging task, but finally got all the pieces retrieved.

The rivets in the vicinity of the eyelets that required removal were drilled and carefully collected to insure no lose parts were left inside the seat ribs.

F-1237E hinges with rivets drilled out and eyelets requiring removal marked in red.

The plan was to hope the removal of two rivets would create enough flex in the hinge and seat pan to allow a thin .020" spacer to be slid under the hinge to act as a shield for a cutoff wheel on a Dremel. As can be seen in the above photo, that plan worked out well.

Using a Dremel outfitted with a cutoff wheel to carefully remove the two offending hinge eyelets on each F-1237E hinge. The .020" shim slid under the hinge did a great job of protecting the underlying seat pan.

After the eyelets were removed, the edges of the hinges were sanded down to remove burrs using the sanding sticks. All and all unless you look really close and notice the missing paint on the edges of the hinges, it looks great. Got lucky with this fix and created no damage in the process.

Using one of the sanding sticks to smooth up the edges of the hinge after removing the eyelets.

Right seat hinges after removing the two offending eyelets on each of the hinge halves.

After successfully removing the offending eyelets from the right seat’s hinges, the same procedure was used to remove the same center eyelets from the left seat’s F-1237E hinges. Once that was accomplished, the hinges were re-riveted onto the seat pans and the seat frames installed in the fuselage thus completing section 26 of the plans.

Both seat frame assemblies installed in the fuselage and ready for the seat cushions.

Becoming Unhinged - Big-time Hinge Faux Pas

It started out being a productive day but the forward momentum quickly changed direction as abruptly as a well hit racket ball ricocheting off the far wall and coming straight for the head.

The recently painted aft seat hinges have sufficiently dried enough to be installed onto the F-1237G seat back braces so thought it would be good to complete the seats today … little did I know they would not get completed. The aft F-1237F aft hinges were Clecoed onto the F-1237G seat back braces and then riveted in place.

Securing the F-1237F aft hinge onto the F-1237G seat back brace with Clecos.

Using the pneumatic rivet puller to rivet the F-1237F aft hinge onto the F-1237G seat back brace.

Finished seat back brace assemblies.

After the F-1237F aft hinges were riveted onto the F-1237G seat back braces the long hinge pin previously set aside requires being cut into two 14 1/2" long pieces and four 5 1/2" long pieces. After the hinge pieces are cut and dressed on the Scotch-Brite wheel the last 1” of each hinge pin is bent to 90 degrees. I ended up using a hand hack saw to cut the pins … those pins are hard steel so it took a while. If I were to do it again, I would use the Dremel with a cutoff wheel.

Doing it the hard way … cutting the hinge pins with a hand hack saw.

Using the seaming tool to make a 1" 90 degree bend on each of the six hinge pins.

All six hinge pins cut to size and bent to 90 degrees … ready for instilling the seats into the fuselage.

Before installing the seat backs in the fuselage, the F-1237G seat back brace assembly requires a #52 hole drilled in it so the hinge pin can be safety wired after the brace is attached to the seat back.

Looking closely at the left side of the photo where my finger is pointing to the location of the #52 hole that was drilled for the safety wire that will secure the hinge pin.

Seatback brace assembly mated with a seat back.

The excitement was building … it’s finally time to install the seat back assemblies in the fuselage. The euphoria was short lived. The hinge pins would not go into the hinges. Huston … we have a problem. Looking closely at the problem quickly revealed the error. In my haste last fall to quickly get parts ready for the last good priming weather, I missed performing the step to remove the center two eyelets on the F-1237E hinges. Actually, it was easy to miss because it was not a step in the instructions but a reference in a figure on the prints. My bad.  As one can imagine, I became unhinged for a few moments and had some choice words for myself. But now this opens up a whole can of worms in that I have to figure out a good way to remove the center two eyelets on each of the four hinges without creating more problems. Need to think about this a bit.

The two center eyelets on each of the four F-1237E seat hinges need to be removed to make the hinge look like the drawing.

This is a colossal screw-up on my part! I’ve got a few ideas for a quick easy fix, but want to practice on some scrap material first.

Right Fuselage Electrical Connector Completed

The remaining fuselage electrical connector was a snap to finish off. The wires going to the ES-00078 blue fuselage electrical connector were first dressed with wire ties and then the connector was mounted onto the F-00034-R mounting bracket. Having previously drilled out the four mounting holes in the seat pan to #19 during the last work session mounting the connector took only a few minutes.

Screwing the ES-00078 electrical connector onto the F-00034-R mounting bracket.

The right ES-00078 fuselage electrical connector mounted on the fuselage.

ES-00077 Electrical Connector Installation Completed

Work continued today on completing the instillation of the ES-00077 blue electrical connector on the left side of the fuselage. Progress began by following the instructions which have the builder tapping the mounting holes in the F-00034-L&R mounting brackets for 8-32 threads. This will allow the electrical connector’s mounting bracket to be secured to the seat pans with four screws per bracket.

Tapping the mounting holes in one of the F-00034 mounting brackets for 8-32 threads.

After the all the mounting holes were tapped, the final touches were made to the wires going to the ES-00034-L electrical connector by way of dressing out the wires with wire ties creating a neat bundle. While access was still good, decided to also place a blob of RTV on the filter capacitor over the wire tie securing it to the standoff … this will insure the filter capacitor stays glued in place over time. Total overkill I’m sure, but I’ll have piece of mind knowing the capacitor can’t move freely.

Wires running to the ES-00077 electrical connector dressed with wire ties and ready for final assembly.

After rounding up all the mounting hardware necessary to mount the electrical connector, a trial fit was attempted only to discover the four mounting holes in the left and right seat pans were not drilled to #19 yet. I really don’t think I missed this step because the blue electrical connector is an upgrade to the kit so the wording may be missing from my plans. It is not a big deal except there was not enough room for a drill so had to use a reamer instead. So builders may just want to drill out these four mounting holes on each of the seat pans to #19 while it is in your hand and not on the fuselage.

Once the seat pan holes were enlarged to #19, the blue electrical connector was screwed to the F-00034-L electrical connector mounting bracket and the bracket was then secured to the seat pan with four screws coated with blue Loctite 243.

Tightening the hardware attaching the ES-00077 blue electrical connector to the F-00034-L mounting bracket.

Completed ES-00077 blue electrical connector mounted onto the fuselage.

I’m quite happy with the way the wiring turned out … the audio wiring is in a loop that swoops up and under the seat pan … the wiring for the blue electrical connector swoops down then curves up and around to the back of the blue connector. This keeps the audio and nav/strobe wiring well separated in areas where the wires extend beyond the shielding.

Installing The Elusive Strobe Light Noise Filter

Behind the scenes progress has been made on the RV-12 in that more miscellaneous  parts have been primed and the hinges for the seats were painted with JetFlex between rain storms. Also installed an additional wire into the roll bar assembly which will be used to support the new canopy latch modification recently released by Van’s which adds a micro switch onto the canopy latch to verify the latch is fully engaged.

As work began on the left blue electrical connector by stripping wires it dawned on me I almost forgot about wiring in the strobe light filter. Humm, … where is that filter? Not having seen the filter for almost two years, the search began … the filter turned out to be quite elusive, but was finally located.

The elusive strobe light power noise filter capacitor assembly.

The strobe light filter consists of a single 2200 uf capacitor rated at 25 volts and comes pre-wired with spade connectors. The negative lead of the capacitor has a ring terminal which is attached to a seat rib for a grounding point.  The positive lead of the capacitor has male and female spade connectors attached to receive the strobe power lead coming from the options connector in the instrument panel … the other spade connector will feed the power on to the left fuselage electrical connector.

I was not happy with the suggested Van’s method of installing the noise filter by way of folding the wires onto themselves and using wire ties to secure the filter to other wires. Some of those wires are audio wires and ideally the noise filter should not be tie wrapped with audio wires. This created a little logistics issue in the mounting which was finally overcome in what I believe is a workable solution by tie wrapping the filter capacitor to a standoff made of vinyl tubing.

Strobe power noise filter placed on a piece of vinyl tubing used as a standoff and tie wrapped onto an existing hole in the seat rib.

A small piece of vinyl tubing was cut to make a standoff and a small wire tie was threaded through an existing small hole in the seat rib, through the vinyl tubing, around the filter capacitor, back through the vinyl tube and seat rib hole. It sounds easy, but was an exercise in patience … however it turned out nice. A #19 hole was drilled in the seat rib and the primer removed so the ground wire would make good contact with the metal to establish a good ground.  After the filter was mounted satisfactorily, work began on prepping the wires for the left fuselage blue electrical connector. Savvy viewers may notice the filter capacitor wires still cross the audio wires … but this should not pose an issue because the white audio cable is a shielded cable and the filter capacitor wires cross it at a 90 degrees … which is ideal for not inducing unwanted noise.

Wiring the left fuselage blue electrical connector was uneventful and the wiring was accomplished using the same pin wiring as posted in the chart from the previous post.

Using the heat gun to shrink a heat shrink label on a wire.

Stripping wires for the open barrel connector pins to be crimped onto the wires.

Finished left fuselage blue electrical connector wiring with noise filter capacitor installed.

Now that both blue fuselage electrical connectors are completed the next step is to rivet the mounting brackets for the connectors onto the seat pans and mount the connectors onto the brackets.

Right Fuselage Electrical Connector Completed

While waiting for warmer temperatures to prime the seat back hinges and some other goodies that were overlooked, decided to move forward and begin wiring up the blue fuselage electrical connector on the right side of the fuselage.

Before documenting the wiring of the fuselage electrical connectors, RV-12 builders using this Blog as reference take note: … deviations in the wiring have been made from Van’s plans. Because the DOG Aviation RV-12 is being built as E-AB and not E-LSA, the decision was made to use shielded cable for wiring the nav/strobe light circuits. This carried over into the landing light power circuits for the two landing lights because of not being sure if the wig wag mode would create electrical noise. Since I already had the shielded cable, decided to go ahead and use it from the instrument panel connectors all the way to the fuselage electrical connectors. The wings already have sheilded wires installed.

The right fuselage connector wiring uses the same pins on the electrical connector as Van’s documentation shows for wiring the connector when installing the lighting kit for the right wing. Because the DOG Aviation RV-12 has an additional landing light installed in the left wing for utilizing the wig wag feature built into the AeroLED's lights, there is the addition of a wire on pin 7. The additional wire on pin 7 will be used to connect the right landing light’s master out to the left landing light’s slave in … this will create a synchronizing of the lights when in the wig wag mode rather than having the lights pulsing randomly.

Using the wire strippers to strip insulation off the wires for crimping.

Crimping the blue electrical connector’s pins onto the wires using the crimping tool outfitted with dies made for 18-22 gauge open barrel connector pins.

For those interested in the fuselage wiring layout, two conductor 18 gauge shielded wires were run from the Options connector at the instrument panel to the blue connector on the right side for both the navigation & strobe lighting power and the landing light & pulse (wig-wag) power runs. The navigation & strobe power runs were tapped into just aft of the F-1203A bulkhead so nav and strobe power could be run to the left and right fuselage electrical connectors from the one source. This is also where the shields on all the cables were grounded as well.

Because I want a separate switch for the left landing light, the landing light power and pulse (wig wag) from the Options connector at the instrument panel was run directly to the right connector. A separate 18 ga shielded wire was run from the right fuselage connector to the left connector so the left landing light could receive power for the wig wag mode. To allow the left landing light to be operable in a steady on state, a separate switch will be installed on the RV-12’s instrument panel to control the left landing light so a separate 18 gauge landing light power wire was run to the left electrical connector … this way I can utilize wig wag operation without creating extra current drain and not tax the electrical system when the right landing light is steady on. If deemed necessary, the left landing light can always be switched on during short final and turned off once on the runway.

The last wires that need to be discussed are the sync wires. Two conductor 22 gauge shielded wire was run from the pins 3 and 7 on the right electrical connector directly to pins 3 and 7 on the left electrical connector. These are for strobe light synchronization and wig wag synchronization. These are data leads and do not require the use of heavier wire. As previously mentioned, the wig wag sync is run from the right light’s master out to the left light's slave in. It could also go from the left master out to the right slave in but I chose to use the right light as a master since it is typically the only light offered in the Van’s lighting kit. Long ago I mentioned this when documenting plans to go with a second landing light but I’ll mention it again. When power is applied the AeroLED’s landing light’s pulse lead, it will cause the landing light to pulse … regardless of power being applied to the landing light’s steady on lead or not.

Finished right fuselage electrical connector wiring.

Left And Right Fuselage Electrical Connectors Wiring Chart

Pin 1 Ground
Pin 2 Stall Warning on left connector …. Vacant on right connector

Pin 3 Wig Wag Sync

Pin 4 Landing light steady on power

Pin 5 Pulse or Wig Wag Power

Pin 6 Navigation Lights Power

Pin 7 Strobe Synchronization

Pin 8 Strobe Light Power

 

Hopefully I can get some priming in today and finish up on the electrical connector on the left side of the fuselage.