Adapting The RV-12’s Control Sticks For Tosten Grips

I was hopeful the temporary bounce in temperature a couple of days ago would offer a good day for priming all the brackets that came in the avionics kit. In recent days, all the parts were totally deburred and readied for a final quick scuffing with Scotch-Brite and Acetone cleaning. Unfortunately, the warm weather was accompanied by 30 MPH plus winds making airbrushing the parts totally out of the question … so attention was diverted back to the control sticks.

Based on the test fit of the Tosten CS-8 grips while sitting in “The Perch” last week, 2 1/4" was cut off each W-1212 control stick using a hack saw. Fellow builders be forewarned … doing this will require quite a bit of filing to custom fit the Tosten CS-8 bushings to the control stick. This is because the bushings are being inserted into the beginning of the transition of the goose neck bend … felt it desirable to get the Tosten grips as low as possible which still leaves them about an inch or so higher than the standard bicycle grip would be. As such, the tubing is no longer perfectly round at this point, so the bushings require a lot of tweaking to get them to fit correctly.  Basically, the Scotch-Brite wheel was used until the lower half of the bushing could be inserted into the control stick. From there on, a nut, bolt and washers were used so the bushing could be removed after pushing it into the tubing enough to put score marks onto the soft aluminum of the bushing. Then the areas of the bushings that showed scuffing were filed a little with a jewelers file … then the process repeated until the bushing went all the way into the control stick.

W-1212 control stick on left after cutting 2 1/4" off to accommodate the Tosten CS-8 stick grips. A bolt, nut and washers made it easy to remove the bushing during many trial fittings.

Saving the fingers during one of the many – many - many insertions and removals by popping the bushing out of the control stick using a clothes pin to pull up on the washer.

Once the bushings were fitting nicely in the W-1212 control sticks, the sticks and bushings were marked so they stay as a matched set. Next a #12 hole for the locking screw needed to be drilled into the forward side of the control stick. The #12 hole is centered 1/2" below the shoulder on the bushing. I used an interesting method to drill the bushing as can be seen on the following photo … don’t recommend this, but it did work.

Progressively drilling the W-1212 control stick to a final size of #12 for the set screw that locks the Tosten CS-8 grips onto the control stick.

Both W-1212 control sticks cut shorter and bushings fitted … now ready for the Tosten CS-8 stick grips.

Checking Out The View From “The Perch”

Every builder has the moment … sitting in the cockpit for the first time, the control stick firmly ensconced in hand, hearing yourself involuntarily making airplane noises. It is a momentous moment … somewhat a right of passage.  Prior to climbing into the cockpit for the first time, the Flightline Interiors box was opened and a seat bottom and back were removed and taken to the hangar to pad “The Perch” for a trial fit.

Checking out the view from “The Perch” for the first time … have to say, the seat in the eagle seems plenty comfy.

The main reason for getting into the cockpit was to get a feel for the position of the Tosten grips purchased at Oshkosh. Because the Tosten grips do not slip down over the control stick, the height of the stick needs to be cut shorter. Because of the unique gooseneck design of the RV-12’s control stick (compared to other RV models) the stick can only be shortened to just above where the bend begins. This is because there is a collar that inserts into the stick to secure the Tosten grip to the control stick. Unfortunately, it will leave the stick a least an inch or so higher than would be ideal for me, but it should be just fine. These grips are really comfortable and designed so either hand can grip them … so even though they will not end up quite as low as I feel ideal, their overall comfort should win out. They simply feel good in the hand.

After purchasing the grips at Oshkosh from Kevin (the owner of Tosten), it was quickly realized that the length of wiring coming out of the grips was not what I would consider long enough for the RV-12. A call to Kevin was made requesting that the wires be made longer. Kevin said he was planning on making the wires longer in future production runs because there are now quite a few gooseneck stick designs these days. In addition, I requested Kevin split the bundle of wires after they leave the stick into two separate bundles of five wires … as opposed to all ten wires in one large bundle. One bundle is for the four way hat switch and the other bundle is for the stick’s other four switches. Each grouping of switches has a common ground wire which is why there are a total of ten wires. The grips were sent back to Tostin in California and Kevin returned a pair of grips with longer wires and the wires were split into two bundles as requested for no additional charge.  I offered to pay for time and materials, but there was no charge … great customer service. Thanks Kevin.

The modified Tosten CS-8 grip with longer wires and two separate wire bundles.

Looking at the above photo, the viewer can easily see the challenge and possibly dilemma of trying to get all those wires fished down through the gooseneck, then make the radical 90 degree and then past either side of the tube weldment dissecting the center of the tubing (which is the pivot point for the control stick). The wires will need to take two paths on either side of the weldment because there just is not enough room otherwise … and still may not be.  I think I have figured out a way to get this done without drilling an exit hole, but will work on it over the next couple of weeks.

Preparing Avionics Kit Parts For Primer

The RV-12’s avionics kit has a handful of parts which require either being separated on the band saw or have areas on the part which require being removed. Yesterday afternoon decided to get at it and separate the parts on the band saw and remove material from the areas requiring trimming.

Using the band saw to separate the F-00045B-L&R mounting brackets.

Noticed there were a few pieces in the avionics kit that were duplicates of pieces included with the fuselage kit such as the protective pieces used to cover the wire run in the center channel, along with parts for under the flap handle and flaperon mixer assemblies. Van’s must be including them now with the avionics kit … which makes sense because they are not needed until the all the wiring is completed. Also included was the ADAHRS stiffener rib modification released by Van’s earlier in the year which goes in the tail cone … I purchased this modification when it was first released by Van’s not knowing they were planning on including it in the avionics kit. So it looks like I have an extra ADAHRS stiffener rib to pass onto a builder who’s completed assembling the RV-12 prior to the ADAHRS stiffener rib being available.

The avionics kit pieces which required either separating or had areas where material needed to be trimmed away.

Having the band saw work out of the way, all of the metal pieces that will be primed were then hand filed to remove the big burrs and smooth out the nooks & crannies. The Scotch-Brite wheel will add the finishing touches to smooth the edges of the pieces.

It is forecasted to get into the 40’s for a couple of days after we get through this entire week of cold ... so hoping the weather cooperates and a priming session can take place outside and the painted parts can be moved inside into the heated drying box to cure.

Avionics Kit Brings Pain - In The Form Of Redo

Having the RV-12’s avionics kit inventory out of the way, decided it would be a good strategy to work on the handful of metal brackets and mounting plates now. These parts need to be primed at some point and in a couple of cases, sprayed with the JetFlex interior paint. That being the case, feel it best to take those parts out of the box and up to the hangar to  deburr the edges of the parts.  The strategy being … if the temperatures bump up at some point in the next few weeks, the parts will be ready for a quick priming session with the airbrush.

The assorted small brackets and mounting plates in the avionics kit which need to be deburred and primed.

After looking at the new parts, it became very apparent there has been a change to the way the instrument panel components are attached. Four of the mounting brackets looked much the same as the four brackets already riveted onto the instrument panel base. The four new parts consist of the F-1200054-L&R  stack angles and the F-1200055-L&R comm supports … these parts apparently replace the already installed F-00026-L&R instrument stack angles and F-00027-L&R comm supports.

The avionics kit’s new F-1200054-L&R instrument stack angles and F-1200055-L&R comm supports.

So it appears some pop rivets need to be drilled out and old parts removed so the new pieces can be installed. I have not read forward in the plans yet, but the part numbers are not the same for the parts in question ... therefore, at this point, I’m inclined to think the new pieces must replace the parts currently installed. If this not the case, I will return from the future and edit this post accordingly.

Photo of the primed F-00026-L&R instrument stack angles and F-00027-L&R comm supports that will require having their mounting rivets drilled out so they can be removed.

Another discovery which truly sucks is the mounting location of the F-1205G ELT antenna mounting bracket. Van’s has the builder mount this bracket on the already riveted in place F-1205 A&C mid fuselage brace components. Here again this will require drilling out 3 rivets so the mounting bracket can be installed. Unfortunately, this is a painted part so a lot of extra care will be needed to keep the paint in good shape. I went back and looked at section 23-3 step 4 in the plans and there is no mention of leaving the three rivet holes associated with the ELT mounting bracket open. RV-12 builders note: When riveting the F-1205A&C parts together which make up the mid fuselage brace, do yourself a favor and leave the three rivet holes open that are adjacent to the holes in the ELT antenna mounting bracket pictured below.

Mounting location for the F-1205G ELT antenna mounting bracket … the mid fuselage brace rivets adjacent to the holes in the mounting bracket will need to be drilled out.

Fortunately, all the rivets that need to be drilled out are pop rivets and not solid rivets so it should not be that bad of a job ... but a pain nonetheless.

RV-12 Avionics Kit Arrives

Frequent followers of the DOG Aviation blog may have noticed there has been reluctance to mate the RV-12’s tail cone to the fuselage. There a few contributing factors to this but mainly it mostly hinges around the ADAHRS  (Air Data and Altitude Heading Reference System) unit which gets installed onto a pair of brackets mounted underneath the tail cone’s top skin. Typically, the tail cone is attached and then the builder needs to crawl back into it making sure to not dent the thin aluminum and then install the electrical connectors, pitot and static air lines onto the ADAHRS unit. This is a task I have been dreading and have decided to order the avionics package early and install the ADAHRS unit in the tail cone now before the tail cone and fuselage are fully mated … think this method will be easier on the body and aircraft as well.

One of the bad things about ordering ANY kind of an electronic item … you  have to just accept the fact ... IT'S OBSOLETE THE DAY YOU PURCHASE IT ... period.  A fact that is hard to accept and typically a good reason to order Avionics near the end of a project … however crawling into the tail cone is not the least bit appealing to me, so decided to bite the bullet and order the avionics kit now.

The DOG Aviation procurement department ordered the RV-12 Avionics kit with an upgrade to the Dynon SkyView D1000 Touch screen and the optional ADSB receiver for receiving weather and traffic that can be displayed on the Dynon SkyView screen. The optional Dynon touch screen has been well received and comments have been very positive as to its functionality … so since it is an inexpensive upgrade, the decision was made the upgrade to the touch screen for the DOG Aviation RV-12.

Arrival of the RV-12’s avionics kit in two boxes … FedX did a good job, the boxes were unscathed from the long journey across the country.

The large box contains the bulk of the Avionics, switch panels, interconnecting cables and small hardware while the smaller box contained the ACK E-4 ELT (Emergency Locater Transmitter) and the backup battery for the Dynon SkyView.  The RV-12 Avionics kit as sold today consists of:

Dynon SkyView D1000 10" Display with optional upgrade to a touch screen
SV-ADAHRS-200 Attitude reference module
SV-XPNDR-261 Mode S Transponder
SV-GPS-250 GPS receiver
SV-BAT-320 Backup battery
SV-EMS-220 Engine Instrumentation Module w/probes
SV-SYNVIS-280 Synthetic Vision Module
SV-MAP-270 Moving Map software with USA FAA Navigation Database
Garmin GTR-200 Com radio/stereo Intercom
ACK E-04 ELT
Switch/fuse panels and control units
Wiring harnesses and mounting hardware

The contents of the large box after the paper filler was removed.

As mentioned above, the Dog Aviation SkyView will incorporate the upgraded touch screen option and in addition, the ADSB option was also ordered which consists of:

Dynon ADSB-470 receiver, antenna, and all required wiring and hardware. This allows SkyView-equipped RV-12s to access FAA broadcast weather, TFR and traffic info in flight with no subscription fees.

Inventory of the parts went well ... nothing appeared to be broken or possibly damaged from transit. The small hardware was inventoried and the plastic parts storage containers were reconfigured as necessary to accommodate the additional parts. There were only two minor issues …. a bad nut - one could see the manufacturer messed this one up and secondly, there were some nuts that were #10 and they should have been #8 according to the inventory sheet.

While doing the inventory, discovered there is an issue that could potentially create an issue for builders. The hardware that is used for mounting the ADAHRS unit onto the brackets in the tail cone needs to be made from nonferrous material. This is because there is a magnetometer inside the unit and having ferrous materials nearby can influence the magnetometer's accruacy. Van’s solves this issue by using brass nuts and screws (coated with a black material) for the mounting hardware.  RV-12 builders take note: An issue I ran into when inventorying bag 2860 is the brass lock nuts virtually look identical to the standard Cadmium plated steel nuts.  The only way to truly identify them is to sort through the nuts with a magnet.

The steel lock nuts in the foreground and the four brass lock nuts and black brass screws are in the background.

A magnet was needed to sort through the lock nuts to identify the brass hardware for mounting the ADAHRS unit.

The brass mounting hardware that will be used for mounting the ADAHRS unit onto the mounting brackets in the tail cone.

Working On Flap Controls

Spent some time working on components that make up the flap controls. The flap handle is a hollow tubular shaft that internally receives a thumb knob, a spring and fork assembly.  These parts allow the flap handle to be raised or lowered then locked in three preset positions. The fork assembly has a pin through it which locks into groves cut into the F-1266A flap detent bracket. The fork assembly has three spacers sandwiched between the two forks this is typically done with pop rivets … but AN470AD4 solid rivets were used in the place of the pop rivets.

Using a rivet gage to determine the correct rivet length that will hold together the fork assembly.

After the flap handle fork assembly was riveted together, it was clamped onto the F-1260A flap handle tube, carefully aligned, then the F-1260A tube was match drilled to the rivet holes in the fork assembly. The assembly was disassembled, deburred, then riveted with LP4-3 pop rivets.

Riveting the flap handle fork onto the F-1260A flap handle tube with LP4-3 pop rivets.

Completed flap handle fork assembly with the locking pin installed.

The next flap control component to be riveted was the F-1266A flap detent bracket. The flap detent bracket becomes sandwiched between two F-1266C flap detent angles then attached onto the F-1266B detent bracket plate.

Riveting the two F-1266C flap detent angles onto the F-1266A flap detent bracket.

One of the two F-1266C angles only has holes on one flange … the other flange becomes match drilled to the F-1266B flap detent bracket plate after the angles are riveted to the F-1266A flap detent bracket.

Flap detent assembly secured onto the F-1266B flap detent bracket plate with Clecos. Note how the nearest F-1266C flap detent angle has no rivet holes … there are holes in the F-1266B bracket plate below which will be used to match drill the angle.

Using the rivet holes in the F-1266B bracket plate to match drill the one F-1266C flap detent angle that had no rivet holes.

After match drilling the F-1266C flap detent angle the assembly disassembled and deburred. Next the six rivet holes in the F-1266B bracket plate are machine countersunk on the bottom side of the plate for AN426AD4-6 flush rivets.

Machine countersinking the six rivet holes in the F-1266B bracket plate with a #30 100 degree countersink bit.

Riveting the flap detent assembly onto the F-1266B bracket plate with AN426AD4-6 flush solid rivets.

Completed flap detent bracket assembly.

Plumbing The Matco Parking Brake Completed

In spite of a limited work session Saturday, was able to finish measuring and cutting the poly brake line tubing along with installing the compression fittings for the brake lines that attach to the aft end of the Matco parking brake. The Adel clamp for holding the brake lines to the right tunnel rib was loosely screwed in position so fairly accurate measurements could be made for cutting the poly brake line tubing.  Once cut marks were made, the brake lines were pulled forward so there would be enough slack to cut the lines and install the components for the compression fittings onto the brake lines. Once again, placing a very thin film of CorrosionX on the tubing made assembling the fittings much easier following the procedure described in an earlier post.

Pressing the brass insert into one of the poly brake lines. Masking tape was used around the tubing to keep the nut and sleeve out of the way.

Sweeping the brake lines underneath the fuel line worked out quite well. The brake lines clear both the bottom skin and the fuel line nicely, plus the Adel clamp will secure their positioning and keep the brake lines out of the way of the rudder cable when it is installed.

Finished attachment of the brake lines to the aft end of the Matco parking brake.

None of the brake lines are tightened yet because the rudder/brake pedal assembly is just temporarily sitting on the tunnel ribs … it will now be removed until such time as the tail cone is attached and a few more wires are pulled in for the buttons on the not yet discussed Tosten stick grips that were purchased at Oshkosh. That said, one can see from the photo below how the overall fit is of the entire assembly.

Rudder/brake pedal assembly temporarily sitting on the tunnel ribs and connected to the Matco parking brake.

 

It is unfortunate Aircraft Specialty came out with the vinyl coated braided Teflon brake line kit for the RV-12 after the bottom skin was riveted in place on the DOG Aviation RV-12. It would have been nice to have had the entire brake system made from braided Teflon brake line. That said, the Aircraft Specialty RV-12 brake line kit configured for the Matco parking brake is a quality offering and should last for many years. I’m very pleased with the quality of Aircraft Specialty’s custom hoses and their great customer service.