Wednesday, November 26, 2014

Successful Installation Of Tosten CS-8 Grips Onto W-1212 Control Sticks

Yes ... It can be done!!!

What’s all the fuss about installing a multi-wire control grip onto the RV-12’s goose neck W-1212 control stick? Just slide the wires through the top of the tubing, pull them out the bottom and move on … right? WRONG!! For starters, the Tosten CS-8 soft touch grips purchased by the DOG Aviation procurement department have a total of ten 22 gauge wires that need to be routed through the control stick. Ultimately, this is akin to stuffing 10 pounds of crap in a 9 pound bag because the RV-12 control stick is not a hollow tube for its entire length … it is segmented twice and has a 90 degree bend at one of the segments. Pictured below is a close-up of the RV-12’s W-1212 control stick. On the left, the viewer can see where the lower portion of the goose neck makes a 90 degree bend … at this location the viewer can also see the outer edges of a metal gusset plate that dissects the control stick, creating two inner chambers. To the right, the 90 degree transition is immediately followed by a tubular weldment which also dissects the W-1212 control stick creating two more chambers (small ones) … this tubular weldment becomes the mounting and pivot point for the control stick. It is at this location where the inside clearances are at a minimum … there is just barely enough room for five 22 gauge wires to slip by on either side of the tubular weldment.
Close-up of the RV-12’s W-1212 control stick … both the weldments being pointed to dissect the tubing … thus creating two chambers inside the control stick at each weldment location which the Tosten CS-8 grip wires must be routed through.

The chambers created inside the RV-12 control stick by the internal gusset and tubular pivot point weldment, coupled with the 90 degree bend, creates quite a challenge for installing wires. As mentioned in a previous post, planning ahead, the DOG Aviation procurement department asked Kevin at Tosten to create two custom CS-8 soft touch grips for the DOG Aviation RV-12. Both grips are provisioned with much longer wires … 3 1/2 foot long (and frankly feel that is still six inches too short but will work nonetheless) and Kevin grouped the wires into two bundles of 5 wires each. One bundle contains the four way hat switch wires, the other is for the remaining switches on the grip. A special request was made of Kevin to also include a 6' + piece of wire sleeve … which Kevin kindly provided as well.

The plan: Use the wire sleeve as a sort of “Chinese finger” to pull the two bundles of wire through the inner chambers of the W-1212 control stick.  Below is a detailed synopsis of the steps utilized to successfully route all the wires through the W-1212 control stick.  The following worked well for me – YMMV.

First, having access to Mike’s fiber optic camera, thought it prudent to have a look inside the control stick for weld goobers and sharp burrs. The camera showed no evidence of anything that would impede pulling wires through the stick other than the total lack of room at the tubular weldment. Thanks Mike.

The multi-step process began by feeding in a thin waxed cord from the bottom of the W-1212 control stick to the 90 degree bend … (making quite sure it did not cross chambers). Then a vacuum cleaner was used to suck the cord the rest of the way through the control stick. The waxed cord (purchased from an arts and crafts shop) is a smaller diameter version of the old style cable lashing waxed cord used before wire ties. The waxed cord was tied off taut with electrical tape to reduce the likelihood of the second cord becoming entangled with it. The process was repeated for passing another waxed cord through the remaining chambers on the opposite side of the control stick.

My apologies for the poor quality of most of the following photos ... forgot to bring the good camera home from the hangar.
Using a portable vacuum cleaner to suck the waxed cord through the W-1212 control stick.
Waxed cord after being pulled through chambers inside the W-1212 control stick .. one down one to go.

Next the waxed cords were tied onto the ends of the extra wire sleeve I requested Kevin at Tosten send me. The ends of the wire sleeves were pulled into the W-1212 control stick from the bottom forming a U. (Felt it was easier to leave the sleeve as one long 6 foot + piece rather than cutting it up).
The ends of the long wire sleeve successfully pulled up through the W-1212 control stick using the waxed cords.

Unfortunately, the heat shrink that Kevin placed over the end of each bundle of five wires to dress out the wire sleeve seemingly make the bundle too thick to pass through the close quarters created by the tubular thru weldment … so the heat shrink was removed and replaced with a VERY TIGHT single wrap of electrical tape … you need to keep it as thin as possible here. This also aids the bundle of five wires with the wire sleve covering to easily slide inside the extra wire sleeve being used as a sort of combination “Chinese finger”/pull rope without fraying or bunching up while being inserted into the second wire sleeve. The wire bundles were inserted about 5 or 6 inches into the “Chinese finger”/pull rope. Of note: After removing the heat shrink on the end of each wire bundle the wires were worked as flat as possible with my fingers and then the existing wire sleeve covering the wire bundle was pulled down as tight as possible over the wires then secured with a very tight wrap of electrical tape.
The heat shrink seen here on the ends of the two wire bundles needs to be removed and temporarily replaced with a very tight wrap of electrical tape after the length of the wire bundles are worked as tight and flat as possible with the fingers and the wire sleeve pulled down as tight as possible.

To aid in pushing the wires into the control stick later, the Tosten provided bushing was slid up the wires and onto the shaft coming out of the CS-8 grip and the distance from the stick bushing to the gusset at the 90 degree bend was measured. The wires were then wrapped with electrical tape from the grip to just about an inch or so shy of where the internal gusset is welded inside the stick (this is where the wire bundles need to split into separate chambers then immediately make the 90 degree bend).
The Tosten provided bushing was slid up the wires onto the shaft of the CS-8 grip and the assembly was placed over the W-1212 control stick so measurements could be made from the point the wires come out of the grip to the internal gusset my finger is pointing to. The wires between these two points were wrapped in electrical tape to stiffen the wires a little so they can be pushed into the tubing easier.

The first bundle of five wires was slid into the “Chinese finger”/pull rope sleeve for about 5 inches or so … the “Chinese finger”/pull rope sleeve was then pulled down tightly over the wire bundle and secured with a VERY TIGHT wrap of electrical tape to the wire bundle.
The “Chinese finger”/pull rope sleeve slid over the bundle of five wires for about 5 inches or so and now ready to have the end wrapped with a VERY TIGHT thin wrap of electrical tape.

Next, while feeding the bundle of five wires into the top of the W-1212 control stick, the additional wire sleeve Kevin at Tosten provided was used as a sort of “Chinese finger”/pull rope to guide the wires through the inner chambers of the W-1212 control stick and out through the bottom. I stopped pulling as first bundle of wires were even with the bottom of the control stick. This should occur prior to the outer piece of electrical tape reaching the tight spot.
First bundle of 5 wires successfully pulled through the W-1212 control stick.
Close-up of where the wires were initially pulled to before moving on to the second bundle of wires.

The process was then repeated for the remaining bundle of five wires. After both of the wire bundles were successfully pulled through the control stick, the remaining length of wire from the grip was then worked down into the control stick while pulling on the ends coming out the bottom of the control stick. It is really a tight fit but the wires will pull through. The outer wrap of electrical tape will snag but the wires should already be through the control stick at this point … so just keep simultaneously pushing from the top and pulling from the bottom. Luckily, after binding a bit, both pieces of electrical tape eventually came out for me with the wire bundles. But if they don’t, it is not a big deal  …. at least the wires will be through the control stick.
The wires for the Tosten CS-8 grips almost completely pulled into place through the W-1212 control stick.
First W-1212 control stick now outfitted with a Tosten CS-8 soft touch grip.

Gee, this was just so much fun … let’s do it all over again for the second W-1212 control stick!
Completed instillation of Tosten CS-8 soft touch grips on both of the RV-12’s W-1212 control sticks.

The Tosten CS-8 soft grips are coated with the same soft coating used on some cell phones and other hand held electronic devices. The coating provides a nice feel to an already very hand friendly and truly comfortable grip.

Thanks again to Kevin at Tosten for the willingness to modify his CS-8 soft touch grips for the DOG Aviation RV-12 and also for providing the extra wire sleeve which proved to be instrumental getting all 10 wires routed through the RV-12’s control stick. I’ll say it again Kevin provides wonderful customer service!

Tuesday, November 25, 2014

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.

Monday, November 17, 2014

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.

Sunday, November 16, 2014

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.

Friday, November 14, 2014

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.

Thursday, November 13, 2014

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
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.

Wednesday, November 12, 2014

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.