WD-1219 Canopy Frame Prepared For Primer

The main reason for wanting to halt assembly at this point in time is so the canopy frame can be primed and possibly painted if weather permits. One of the first steps in the canopy instructions is to machine countersink two #12 holes just aft of the bushings on each side of the canopy frame. I installed the countersink bit with the #12 pilot into the countersink cage and proceeded to make aluminum shavings.

Machine countersinking one of the screw holes using a #12 countersink bit in the countersink cage.

After the two holes were machine countersunk, work began on deburring and smoothing the edges of the canopy frame.

Using a file to deburr the forward portion of the WD-1219 canopy frame.

The instructions have the builder filing down a weld on the upper portion of the bow so it is no higher than 1/32" ... this is so it won’t interfere with the canopy.

Weld on the upper bow of the F-1219 canopy frame which needs to be filed down.

Filing down the weld on the upper portion of the bow on the canopy frame making clearance for the canopy.

Unfortunately, the late afternoon start and time taken to remove the rod ends from the flaperon push tubes did not allow for finishing the deburring process on the canopy frame, so that will be continued during the next work session.

F-1265 Pushrods Successfully Disassembled For Deburring

Yesterday morning was spent running errands and thinking about the dilemma facing me regarding the removal of the AN490HT11P threaded rod ends from the F-1265 flaperon pushrod tubes for deburring. On the way to hangar later in the afternoon, a detour was made to Home Depot aircraft supply … while wandering around the store, a plan of attack was slowly formulated which ultimately worked without damaging any of the components.  I already had a piece of chain which I though may be useful, so while at the store the final plan was formulated around using the chain. A few nuts, bolts, small and large washers, saddle for a 4x4 post and wooden dowel rod later … it was off to the hangar.

Prior to attempting removal of the AN490HT11P threaded rod ends from the F-1265 flaperon pushrod tubes one rivet hole was chosen for marking so after the parts are separated, a wire and label can be used to mark the mating rivet holes so they can be aligned correctly after deburring and primer.

The plan …. slide a small washer over the threaded rod end to protect the finish there the threads meet the base of the rod end, cut a small piece of vinyl tubing and slip it over the threads to protect them from the steel 4x4 saddle. Secure the saddle with two fender washers and two nuts. Attach the chain to the open ends of the 4x4 post saddle and pound the chain with a mallet creating outward force.

The fixture looks a little medieval and is truly Jerry-rigged … but it did get the desired results.

Pulling out the overly tight AN490HT11P threaded rod end from the F-1265 flaperon pushrod using carefully calculated and steadily increasing brute force from a mallet.

Once one end of the tube was opened up, a wooden dowel rod was inserted and the other AN490HT11P threaded rod end was pounded out from the inside.

After successfully removing all the AN490HT11P threaded rod ends from both the F-1265 flaperon pushrods, the holes were deburred and tagged for correct reassembly. Of course reassembling the parts will be super critical because they will need to be pounded together and rivet hole alignment will be critical.

Skipping ahead in plans to the next fabricated part that will need primed landed me at making up the F-1260A flap handle tube which will become a component inside the flap handle assembly. The F-1260A flap handle tube is made from a piece of AT6 .035x7/16 tube. To save time, it will be drilled for rivets later after priming.

F-1260A  flap handle tube cut, deburred and ready for primer.

Fabricating The F-1264 Pushrods & F-1265

Prior to priming the canopy frame there are a few parts that require fabrication which I would like primed as well. First up, the F-1264 control stick pushrods which are fabricated from AT6-058x5/16 tubing.

Using the band saw to cut one of the F-1264 control stick pushrods.

Fellow RV-12 builders take note: After cutting the pushrods per the plans and deburring, discovered section 32-04 step 4 of the instructions omitted the information necessary to drill and tap the tubing. Older versions of the plans call for using a #3 drill and tapping 1/4 - 28 threads … but my “updated” version of the drawing was missing that information. Thanks to Joe in Michigan for chiming in on the forums saving me from needing to wait until late Monday morning to call Van’s. It sure would have been far easier using a lathe to drill out the F-1264 control stick pushrods … however, not owning a lathe, had to Jerry-rig a jig to hold the tubing from V blocks and used the drill press to drill the holes.

Drilling the control stick pushrods on the drill press using a #3 drill bit in preparation for tapping the ends of the pushrods.

After drilling out the ends of the F-1264 control stick pushrods using a #3 drill bit, the ends require tapping. A tap with 1/4- 28 threads is then used to thread the ends of the pushrods.

Tapping the F-1264 control stick pushrods for 1/4- 28 threads.

Finished F-1264 control stick pushrods - #3 drill bit and 1/4- 28 tap callout can be seen missing from both step 4 and figure 4 of the plans.

The F-1265 flaperon push rods are made from a long tube and required being cut by hand using a hack saw. I measured the tube and there were a few inches extra so a rough cut was made with a hacksaw a little long and then a final trim cut was made using the band saw.

Using a hand hack saw to rough cut the tubing for the F-1264 flaperon push rods.

After the F-1265 flaperon push rods are cut to the proper length, the tubing is marked for four equally spaced holes which will be drilled into the AN490HT11P-SDM 0.634 threaded rod ends. Fellow builders take note: Here is where I created a big mess for myself … after marking the rivet hole locations I used a spring loaded center punch to center punch the hole locations on the tubing for drilling. Apparently the process of center punching the tubing ever so slightly deformed the tube making the insertion of the threaded rod ends by hand impossible. Mind you, the threaded rod ends are a really tight fit to begin with, so would suggest not center punching or at least place the threaded rod ends in the tubing first which may help hold the shape of the tubing.

Tapping the AN490HT11P threaded rod ends into the flaperon pushrod using a small deep socket to protect the threads on the rod ends. A coating of Boelube was used in the hopes the threaded rod ends can be removed for deburring.

After all the threaded rod ends were in place in the two pushrods, four equally spaced holes were drilled at each end of both tubes which will be used to rivet the pieces together.

Drilling the fourth equally spaced #30 rivet holes into the flaperon pushrod/threaded rod end assembly. Clecos were used to keep position but the fit was so tight that nothing would have moved anyway.

Both F-1265flaperon pushrods with holes drilled into the AN490HT11P threaded rod ends.

The big challenge for the next work session will be removing the AN490HT11P threaded rod ends from the flaperon pushrods for deburring without destroying them. Hoping I may get lucky in that the process of drilling reduced some of the pressure in the area where the tubes were center punched … but I know that is being overly optimistic. It is going to be a fight to get the pieces separated.

Routing ADAHARS Wires Into The Tail Cone

Prior to moving on and fabricating parts for the upcoming primer session, the remaining wires for the ADAHARS were pulled through the wire ties in the tail cone. There are two twisted pairs and one cable with multiple wires inside that make up the wiring to the ADAHARS … plus the two wires from the temperature probe.

Pulling in one of the two twisted pairs going to the ADAHARS. In the foreground the other twisted pair and white cable that also go to the ADAHARS can be seen.

More Power - By Way Of Pat & George’s Farm

The better part of last week was spent out of town helping out with a relative’s move into a house. While out of town, purchased a Champion 3500 watt RV generator that boasts 4,000 watts peak power which was on sale … having high hopes it would power my air compressor at the hangar. Here is a perfect case where on paper it should work but reality is something entirely different. The air compressor motor is 1.6 HP at 13 amps. To figure wattage, 110 volts multiplied by the 13 amps comes to 1,430 watts. In theory, a 3,500 watt generator with a peak of 4,000 watts should work. Bottom line ... the new generator was not robust enough to deal with the air compressor. Bummer!

I have been kind of hot to trot on getting the air compressor running because the weather this week will be favorable for spraying primer on the canopy frame and few remaining parts that still need fabricating. We are getting to that time of the year when nice warm days are the exception and not the norm.

The new Champion 3500/4000 watt generator was just too anemic to run the air compressor.

I know electric motors draw a very large amount of current for few moments during startup and was hopeful the generator was large enough to keep up. Nope … the generator could not handle the large inrush current. The engine loaded down and never recovered. This could be because the 198 cc engine did not have enough torque, or the governor responds to instant loads much too slowly. Guess the Southern Outpost has a new generator for the frequent power outages there.

Generator two - Mike borrowed a slightly larger generator he sold to a friend a while back and it almost worked. The compressor would spin up if the tank was empty but would not start up when the regulator tried starting the compressor to fill the tank while it had air in it. Double bummer!

Generator three - The last ditch effort came by way of Mike’s sister Pat. Pat and her husband George own a farm and have a 6,000 watt generator with a 10 hp Briggs and Stratton engine to run the well pump during extended power outages so the animals can have water. George pulled the generator out from the barn, checked that it started and graciously loaned it out for the spray painting job this week. (Yes, California friends, we do have farms and barns in Ohio). Thanks Pat and George for loaning the generator to DOG Aviation.

On the left, Pat and George’s 6,000 watt generator straight off the farm easily handled the air compressor … on the right, the generator Mike sold to a friend which almost but not quite got the compressor spinning.

Static Air For Backup Instruments Installed

Those RV-12 builders building their aircraft as E-LSA can, by in large, ignore the entire contents of this post. Early on the plan has been to outfit the DOG Aviation RV-12 with a couple of tried-and-true steam gauge instruments for backup … in particular, an airspeed indicator and altimeter, both of which requiring a static air source.

As mentioned in a previous post, one of the reasons the side skins have been left off is just in case it was necessary to establish an alternative routing through the fuselage for the static air line and/or the tubing from the wing for the Angle Of Attack (AOA) display which will run into the tail cone.

Because the ADSB antenna cable is routed through the center tunnel, there is not an abundance of extra room in the wire grommets between the aft bulkhead on the center channel and the aft bulkhead on the fuselage. At first I was not going to install the static line in the center tunnel grommets because the fit appeared way too tight. However, with a little rearrangement of the wires and pitot tube already in the grommets, the necessary room was made to insert the 1/4"static air tubing. Don’t get me wrong, it is still a tight fit … but not so tight that adjacent wires can’t be moved like it was prior to arranging the wires in the grommets better.

Installing the extra static air tube through the wire grommet on the aft bulkhead of the fuselage.

I did find a time saving step that made one person instillation a little easier. A couple of small pieces of tubing were cut and placed into the wire grommets to hold the positioning for the static air tubing. A piece of tape was wrapped around the tubing to seal it off from dirt and extended slightly beyond the end of the tube and formed into a point. When installing the tubing into the grommets, the tape point was inserted into the small tubing pieces used to hold positioning ... as the static air tubing was pushed into the grommets, the small pieces of tubing slid out the other side. This worked quite well.

Two of the small pieces of tubing used as guide tubes can be seen here adjacent to the already installed pitot tubing passing through the two wire grommets.

Fortunately, on the forward side of the center channel, there are two wire grommets in each bulkhead. The lower one is really full because of the many extra wires that go up to the center channel conduit so the upper grommet was used to pass the static air tubing. So the upper grommets were used to pass the static air tubing the rest of the way to the instrument panel.

The upper wire grommet on the forward side of the center channel was used to pass the extra static air tubing on its way to the instrument panel.

Fishing the extra static air tubing through the center tunnel using the upper grommets in the bulkheads from the center channel forward.

The extra static air tubing now shares the same grommet that the ADSB antenna wire passes through.

Aft of the fuselage, the extra static air tubing was placed in the same wire grommet as the ADSB antenna cable, routed to the left side of the tail cone and through the existing tire ties.

Routing the extra static air tube through the wire ties already on the tail cone for the wiring and pitot tubing.

After finishing the routing of the extra static air tubing from the tail cone to the instrument panel through the center tunnel wire grommets, the routing path for the small Tygon tubing for the AOA was looked at. Because the Tygon tubing used for the AOA indicator is so soft and malleable, decided not to run it into the stuffed wire grommets aft of the center channel for fear of it becoming compressed. Will cover its instillation in the next post after I finalize a good routing for the tubing.

Scotty, I Need More Power – Lots More!

No work on the project today but yesterday Mike and I decided to use expanding foam insulation around the perimeter of the hangar walls where they meet the concrete floor. Earlier in the year the floor had a bunch of water on it which was caused by snow piled up at the far end of the hangar row. As the snow melted, the runoff made its way from hangar to hangar including the DOG Aviation hangar. In an effort to make a preemptive strike at eliminating water in the hangar, decided to try sealing the base of the metal hangar walls with expanding foam which will hopefully act as a dam and prevent water from entering from adjacent hangars. So everything that was placed along the walls was pulled out so the floor could be swept and blown with air from Mike’s portable air compressor.

Mike applying the expanding foam to the base of the back wall of the hangar. The treated area can be seen on the left.

 

Mike laying out a nice bead of expanding foam along the back wall of the hangar.

After the expanding foam was applied, the shop was straightened out once again and I decided to use the big air compressor for the first time. Plugged it in, turned it on … and it barely began to turn. What? Decided to try another outlet that I know is on another circuit and the air compressor turned a little faster … but still no dice. Bummer. Scotty, I need more power!

Got to thinking about it and it is a 13 amp compressor so it takes more than a little power to get it moving. The circuit is only 12 gauge wire and the wire run goes to the breaker panel at the far end of the hangar row which wire distance is likely around an easy 200 feet. The 12 gauge wire has much more voltage loss than optimum … but one thing is certain … the air compressor will NOT be running on house power.

Guess it is time to go shopping for a small portable generator …that sucks but shy of running a #6 wire, just don’t think there is anything that can be done.

Even though my exuberance was squashed due to the anemic electrical outlets in the hangar, decided to suck it up and make something happen on the RV-12 … so moved the tail cone in close proximity behind the fuselage so the wiring to and from the tail cone could be installed, along with pulling the pitot tube through the fuselage’s center section. My method for doing this is a departure from the Van’s plans which would have the builder doing this with the side skins on … but there is a method to the madness, so to speak. The plan is to install a backup altimeter and airspeed indicator in the RV-12’s instrument panel which will require running a static air tube up to the instrument panel plus there is the angle of attack indicator tubing which needs to be run back to the tail cone. The wire grommets are getting really full and I know there is room for the trim wires and pitot tube … but just in case the static air or AOA tubing won’t fit, by having the side skins off, it will offer options for routing in case the wire grommets get maxed out.

Routing the pitot tube in through the center tunnel wire grommets.

After the pitot tube was routed, up through the center tunnel, the wire that goes to the pitch trim motor was pulled in through the wire grommets in the center tunnel.

Routing the pitch trim motor wire through the center channel wire grommets.

 

Finished for now the pitot tube and pitch trim motor wire successfully run through the center tunnel wire grommets.

A test piece of the static line was able to fit into the aft grommet on the fuselage which is great news … however, the center channel grommet has one more 18 gauge wire in it so it may not be a piece of cake getting it pulled in through the center tunnel.  Hopefully, will give it a go tomorrow if other obligations get fulfilled in the morning.