To cushion the bottom of the tank I got some 1/8″ thick neoprene. The best deal I found was sold as “tool box drawer liner.” I cut it so it is wider than the bottom so it wrapped up the sides a little then notched out the inboard rear edge to match the plywood.
The tank needed two holes, one for the drain and one for the fuel level sensor. I first drilled a small pilot hole then used a 1/2″ forsner bit. Never use a regular twist drill bit for this step, you will end up with a triangular shaped hole instead of perfectly round and the bushing won’t seal.
Then installed the rubber bushing.
At this point I realized this particular tank is too deformed to install the fuel level sensor because the top and bottom are curved inward so there is not enough clearance for the sensor.
Knowing these tanks do expand the first time they are filled with gasoline I had to stop the installation and fill this tank with gas and hope that resolves the problem. After a few days the tank was still deformed, so I sealed the tank and put a few psi of air pressure in it. The following day I removed the air pressure and let it sit with gasoline in it. After a few more days the tank is back to its normal shape and has held that shape for over a week.
Now I can install the fuel level sensor. I made sure that the sensor was about 1/4″ above the bottom of the tank and pressed it into the bushing.
I was concerned that the polycarbonate cover might bump the calibration switch on the sender so I cut a ring of plywood to protect the switch. I used some silicone to hold the ring in place.
The drain hole in the bottom of the tank was drilled and fittings installed.
Now the tank was installed into the wing. To hold it in place I purchased some tie down straps. They were way too long so I cut them shorter and heat welded the end so it does not fray. I routed then under the plywood and diagonal supports then over the top of the tanks.
The fuel line was routed from the elbow to a tee. Then to the drain and quick disconnect. This was not an easy task to accomplish without kinking the lines. It would have been easier if the quick disconnect was moved an inch or two forward but that would have made the quick disconnect higher which is undesired and more likely to get bumped by my elbows when sitting in the cockpit. Maybe cutting one barb off of the tee would help too.
After installing the cover panel I’m amazed at how well it looks.
Not much remains on the wings now. Grease aileron bearings, safety wire aileron bracket bolts, install wing tips and I need to get the rest of the wing polished so it shines like the tank cover and ailerons.
Time to route the fuel level sensor wires. The first thing I did was mount the wings and locate a location to drill a hole for the wires. After drilling the hole I added a grommet.
After locating the hole I determined how much wire needs to protrude from the fuselage so they can be easily disconnected after removing the wing.
The sensor outputs need routed to the fuel selector switch so I decided to make some splices near the sender switch to accommodate this. I routed the left fuel sensor wire down the left fuselage side, across the floor and up the right side and through the grommet. On the right side near the fuel selector switch I spliced in the fuel selector and right side sender wires.
The red and black (power and ground) are spliced to the right side sender so both senders get power. The white wires from each sender are spliced to the wire going to the selector switch, right to red and left to black. The white wire from the dash and to the selector were spliced.
Terminal ends were added, the resulting harness looks pretty good.
Behind the dash the black is connected to ground, red to power and white to the green EIS Aux input.
Two fuel lines pass through the firewall. One is from the electric fuel pump, the other is gravity feed. In the picture below the right line comes from the electric fuel pump. The inline check valve ensures fuel can only flow towards the engine.
After the check valve is a tee, shown below. Left side connects to the electric fuel pump check valve, right to mechanical pump check valve and the top goes to the carburetor. Behind the tee is the inlet for the mechanical pump. It’s fuel line is connected to the left line in the picture above. Rest assured, the top hose now has a clamp, it was not installed when I took this picture.
Below you can see the mechanical fuel pump on the right. The outlet connects to a check valve that’s connected to the tee. I wrapped some silicone tape around the check valve so won’t chafe nearby components.
The outlet of the tee connects to the fuel inlet banjo on the Dellorto PHBE34BD3 carburetor.
This is one complaint I have about the Hirth F-33, it came with the fuel pump and carburetor. The outlet on the fuel pump is made for 1/4″ (6.3mm) ID hose but the inlet on the carburetor is only 6mm. To resolve this I ordered a new fuel inlet banjo, Dellorto part number 6273 that has a larger diameter barb.
Now all I need to do is fasten the fuel tanks in the wings and install the air filter and she is ready to run!
I’ve spent many hours researching and thinking about the best way to design the fuel system. Originally I planned to use the five gallon fuselage tank that came with my kit. But after deciding to register my airplane instead of going Part 103 I decided to add wing tanks. It would have been nice to use the fusealge tank as a header tank but the fact it interferes with my toes when working the rudder pedals I decided it would be best to remove it. Maybe I can build a custom header tank that does not hit my toes but for now I decided to move forward without it.
Starting at the wing we have the valved quick disconnect. I used a 90° male end to keep the hose along the fuselage side.
Directly after that are the fuel filters. This location is easy to access for service and inspection.
I still wanted some sort of header tank to ensure the fuel pumps won’t suck air when I’m banking and the tank is not full. The simplest solution to this was to add an inexpensive one quart tank for each wing tank.
These were originally designed for radiator overflow and came with a small vent hole that I sealed with some heat.
The bottom of the tanks are routed to the right and left input of the selector valve. This valve is from a jet ski, easy to find so it can be replaced periodically before it fails. It only provides left, right and off positions. For midwing airplanes, like mine having a both position could result in the pump sucking air from an empty tank instead of fuel from the full tank.
After the valve is a tee, each outlet is connected to a different fuel pump. An electric pump and a mechanical pulse pump on the engine. I mounted the electric pump in the fusealge right after the valve.
Some day I’ll need to drain all the fuel so I can replace fuel lines, valves and to service the fuel filters. The outlet of the electric pump connects to a tee, one outlet towards the firewall, the other to the Curtis drain valve I installed on the bottom of the fuselage.
Mounting the valve was simple after making a retaining bracket out of some plywood and a piece of RS-7. The bottom plywood is made from 1/8″, this is needed to lift the brass piece off the floor to leave room for the hose clamp.
The RS-7 was cut so it fits around the brass piece and then some 1/16″ ply was added as a top.
The round part on the brass is 0.550″, I used a 1/2″ forsner bit and a file to make the hole. I placed the brass piece in the hole and slid the retainer over the brass to through drill the two mounting holes.
Next I used a small file and made a notch from the body hole to one of the mounting holes.
This will allow the Curtis valve to fit through the hole.
The retainer is slid over the valve and mounted in place.
Some of these pictures were taken before I tightened down the drain valve into the brass. Before I did that I coated the threads with Permatex Aviation Form-A-Gasket to help ensure I have no leaks.
Added some washers and lock nuts and the drain is ready for use.
The nice feature of these valves is that they have a mating drain hose that locks onto and seals against the valve so you can drain without spilling or dripping fuel.
To speed up draining just turn the Facet pump on, using the selector valve you can select what tank to drain.
I used some copper pipes to make the penetration at the firewall. The reason I did this is for safety. If there is ever a fire in the engine compartment the blue fuel line will melt from the heat and I’d have fuel leaking by my toes near a fire. The long copper lines will take some time to transmit heat from an engine fire all the way back to the blue lines.
I’ll cover firewall forward in a future post.
Long time since I’ve posted anything but I’ve been busy painting. So glad I built these wing racks, made working in this small garage so much easier.
The first wing wizard worked ok, after using it a few times I realized it needed some improvements. To start with the base needed to have less flex in it. So I used a 4×4 for the main cross piece and some 1×4 for the caster supports. A 4×4 was way Overkill but it was cheap and simple. Besides the extra weight adds some stability.
2″ PVC was used to connect the two bases, the bottom tee was notched to allow the rotation of the bases. The base was drilled in the center and a piece of PVC was inserted to fit up into the tee.
When rotating the wing, locking the wing in place is easy with the cam lock nuts from Rockwell.
To raise and lower each side I purchased a couple trailer jacks from HarborFreight and mounted them with some exhaust pipe clamps. Don’t get tempted to get a square tubing jack, you want the arm to rotate so you don’t have to remove the arm to clear the struts.
To hold the wing some soft carpet was combined with 2″ tie down straps to create a nice cradle less likely to damage the wing than the previous design.
Both wings easily store in my one car garage.
I did write down all the dimensions but have not taken the time to post it all here. The bases have the same measurements so should not be hard to figure it out from my original design. If you are interested in this information leave a comment, might motivate me to make a more detailed post.
Installing the wings, even with a helper, is a pain. While I can do it alone and it’s not that time consuming it can be frustrating and it’s really easy to damage the wings moving them around. I’ve been wanting to make this process easier since I built my wing carriers long ago and I finally came up with an idea that works!
I’ve basically built a set of sawhorses, on wheels, that transforms into a wing rack while the wing is resting on the sawhorses. Watch the video to see it in action:
Now, time to start building this, your gonna need some materials:
|2||2″ PVC pipe||62-1/2″||Main horizontal support|
|2||2″ PVC Pipe||12″||Main vertical support|
|2||2″ PVC pipe||1-3/4″||Reducer connector|
|2||2″ PVC pipe||3-1/2″||Rotator for base|
|2||1.5″ PVC pipe||25″||Vertical slider|
|2||1.5″ PVC pipe||6″||Arm rotator|
|2||1.5″ PVC pipe||20″||Lower arm|
|2||1.5″ PVC pipe||28″||Upper Arm|
|6||1.5″ PVC pipe||1-3/4″||45° connectors|
|2||1.5″ PVC pipe||3-3/4″||Bungee holder|
|2||3/4″ PVC pipe||3-1/2″||Bungee hook|
|2||3/4″ PVC cap||N/A||Bungee hook|
|2||2″ PVC 4-way||N/A|
|2||2″ PVC Tee||N/A|
|2||2″ to 1-1/2″ PVC reducer||N/A|
|2||3″ sch 30 cap||N/A||Mount to base|
|2||3″ to 2″ sch 30 bushing||N/A||Mount to base rotator|
|8||1-1/2″ PVC 45° elbow||N/A|
|4||1-1/2″ PVC cap||N/A|
|4||1-1/2″ PVC Tee||N/A||Arm rotator assembly|
|6||Wing Nuts||N/A||Replacement wing nuts for lawnmower handles|
|8||3″ casters||N/A||All must be casters, preferably locking too.|
|32||5/16-18X1″ carriage bolts and nuts||N/A||Attach casters|
|??||Various small screws||N/A|
|6||1×4 common board||44″||Base|
|4||1×4 common board||18″||Attach casters|
|2||1×4 common board||56″||Attach casters|
|2||bungee cord||4′||Flat cord bungee|
Note: Do not use “sanitary” fittings, they will not work.
Many of the PVC parts will need modified, a lathe would make most of the modifications easier. A mill would be nice too. I used a Dremel and a drill press.
Let’s start at the bottom and work out way up.
The ends of two 44″ boards need notched to accept the 18″ boards. The notch in the 18″ boards starts 4″ from the end. I glued the there pieces together.
The rear two 44″ boards have a small notch cut in them to clear the 18″ boards. This board was glued and screwed to the back side of the platform.
The front 44″ board also needs notched but it needs to be lower. This board was added as a modification so some pictures might be missing it.
Before gluing this board I pre-tensioned it with some twist to counteract the off-center weight when the wing is in the storage position.
If your wondering why the board is pre-tensioned look at the picture below.
The casters are bolted to corners and the 3″ PVC cap is bolted in the middle.
Grab the two 2″ tees and cut a notch for the wing bolt that goes 90°. It is ok to go more than 90 but if you can make it exactly 90 you will be happier with the end result. Remember to make a right and left version, the tees should be mirrors if one another.
Now grind out the inside of the notched part of the tee until a 2″ pipe can easily rotate within the tee. Now glue the 3-1/2″ long 2″ pipe into the 3″ to 2″ reducer. Once the glue is dry insert it into the tee, ensure it freely rotates when fully inserted. Now mark the center of the notch onto the pipe. Drill a hole, use a small chisel to make the hole square for the carriage bolt.
The carriage bolts for the wing nuts need modified a little bit to better match the contour of the pipe. A vice and a file made this pretty easy.
Grab the 12″ long 2″ pipes. Cut a slot in them, this will be the height adjustment. I used my drill press to drill a line of holes then used a file to produce what you see here.
Grind out the inside of the two 2″ to 1-1/2″ reducers until a 1-1/2″ pipe easily slides through the adapter.
You can now assemble the main part of the base.
Set the PVC base into the caps. Now adjust the base rotation wing nuts. The vertical boards on each caster platform should be facing each other.
Once adjusted to your liking use some small screws to attach the reducer and cap.
Now get two of the 1-1/2″ tees and notch them for the wing nut. Again remember to make a right and left. The length of the slot is not too important, I made mine much more than 90° but depending on how much rotation you need you might want to do something different.
Now grind out the inside of the tee until a 1-1/2″ pipe easily rotate inside the tee. Go ahead and glue the 25″ 1-1/2″ pipes to the tees. You might be tempted to cut square hole for the adjuster, but wait till later when you can better align everything first.
Now take the remaining PVC parts and build two candy canes, again be sure to make a right and left.
The 1-1/2″ long PVC pipe needs a notch cut in it so the bungee cord can exit the pipe. The “cap” will slide over the end and is secured with two small screws.
A board was cut to create a flat platform for the bottom of the wing. I used a 2.5″ hike saw to notch the end and a 45° bevel wad added with the router.
The board was drilled and counter sunk then attached with some drywall screws I had laying around. Then it was covered with some self adhesive pipe insulation.
To adjust the tension on the bungee, wrap the cord around the hook before inserting it into the pipe. I did need to bend the hook a little too make it narrow enough to fit into the pipe.
Now you can assemble everything and mark the locations for the adjusting bolts.
ADS-B ( Automatic Dependant Surveillance Broadcast ) provides much needed information to pilots and air traffic controllers. ATC can see the location, speed and direction of any aircraft equipped with ADS-B out. Pilots can see other aircraft with ADS-B out and get updated information such as weather and temporary flight restrictions. Historically getting access to this data required expensive avionics but recently a few low cost solutions have appeared.
With some specialized software European USB TV tuners can pickup the ADS-B signals and thanks to mass production such devices can be purchased for under $20. I purchased a tuner that comes with an external antenna from Amazon.
Using a USB OTG cable I connected the tuner to my tablet.
If you need more detailed directions to get this setup head over to the site that made this possible: http://hiz.ch/index.php/home/adsb-receiver
The FAA has mandated that aircraft flying in nearly all controlled airspace must be equipped with ADS-B out by Jan 1st 2020. I hope this mandate helps drive some competition in the market and bring down prices of ADS-B out transponders. In the meantime at least I can pickup ADS-B in with little investment.
Running all of the electrical wiring is a larger task than I anticipated. Figuring out what needs connected to where is easy enough, doing so in a nice tidy, serviceable and long lasting way is what’s hard.
I secured the battery with a battery hold down strap. I had to shorten it significantly and heat weld part of it since I don’t have a sewing machine. A piece of foam is placed under the battery to keep it from sliding around.
I added a ground controlled relay for the master power. When the matter switch is off no power enters the cockpit and nothing electrical is energized. For those unfamiliar with airplanes, the engine ignition system is independent from the electrical system so the master switch will not turn off the engine nor prevent it from starting. The ignition is controlled with the keyed switch, more on that later.
Installed a diode across the starter solenoid. This reduces arcing across the starter switch contacts. Also, ACS service bulletin sb92-01 applies to my ignition switch and requires the installation of the diode. To protect the diode I put it in a small tube and covered it with black heat shrink.
The regulator was mounted to the other side of the fuselage and it’s wire run through wire clamps on the engine just like the EGT and CHT probes.
All of the circuit breakers are on the dashboard so most of the power distribution happens there.
A small ground buss provides a convenient place to connect ground wires.
The keyed switch serves a few functions. When the key is removed the engine magnetos are disabled so the engine will not start, without this simply bumping the propeller could start the engine. The key also has a momentary start position to activate the electric starter, just like a car. It has a run position wherever both magnetos are allowed to operate and a left & right position where you can select the right or left magneto to ensure both are working before taking off.
Still have some other items that need wired, strobe, fuel pump, USB chargers and the radio. I’ll discuss that in a future post.
The stock exhaust on my airplane was about as attractive as Muppet Gonzo’s nose. The stock exhaust provided by Hirth looks fine on most aircraft with the muffler hanging dead center of the airplane. But the steering bar for my nose wheel would run right through the muffler so that’s not an option. I managed to make it fit but it was ugly.
My engine was purchased from Recreational Power Engineering so I contacted them to find out the proper way to go about this modification. Matt said the total length from engine to muffler needs to be 21″ and the pipe diameter should stay the same size throughout but could be slightly larger just never smaller. Bends are the tricky part, a regular pipe bender will slightly crush the pipe so that’s not an option. RPE sells pre-bent pieces that you can use to build your custom exhaust or you they can build it for you. I managed to make things work without needing any additional bends
The first problem I had was the 90° pipe coming off the engine does not match the angle of the fuselage bringing it too close to the fiberglass and wood. I cut the straight part at the rear of the 90° off and then cut a little off of the bend, you can see the little notch in the left picture below to see the small section I removed. The result is a 65° degree bend. The straight part was also rotated so the springs will be top/bottom instead of side to side. Again this was effort to get more clearance between the fuselage.
The muffler having a 90° elbow welded to it is not going to work so I cut it off.
I don’t have a welder here at my house so I made a template of the of the fuselage shape, marked some key locations and took this to my brothers automotive shop to weld the parts.
He tack welded all the parts so I could take them home and verify fit, if anything needs tweaked the tack welds can be easily cut.
Back home I checked the fit and was satisfied so I created a bracket to hold the muffler onto the fuselage. The bracket was made from some 3/4″ wide steel that I shaped to match the curve of the muffler.
I used a couple large zip ties to hold the bracket in place so I could check the fit. Once satisfied I marked the locations where the new spring hooks need to be welded. Back to the shop for the final weld.
The result is a much better look than the stock system that came from Hirth. The only downside is when it comes time to replace it, all this customization will need recreated again.
I also checked that it flexes properly when the engine moves.
I’m undecided on how I want to paint the exhaust. Black is obvious, maybe I could use red and white to match the fuselage color scheme. Maybe I’ll decide to wrap it. Need some time to think about this.
The EIS monitors the cylinder head temp, exhaust gas temp, RPM, battery voltage and air temperature. Each item can have limits set so if something is out of the ordinary the warning light on the dash will illuminate.
The cylinder head temperature probes sit between the sparkplugs and head. I ran the wires through the fins and up the side of the engine where they are held in place with a clamp. The exhaust gas temperature probe wire is also held by this same clip.
The probe wire then run to the front of the engine where another wire clamp was added.
The EIS harness terminates in from of the battery where the probes are connected. I kept the pair of wires for the second exhaust gas probe in the harness even tho I’m not using them. Maybe some day this airplane is updated to two cylinder and then they are needed.
The grey tachometer wire goes to the other side of the engine and connects to the lighting coil. I spliced an extra connector into the voltage regulator wires to connect the tach input. Still need to put an end on the grey tach wire.
The EIS uses a single DB-25 connector for all the wires. I took the connector apart and removed all of the unused wires by pushing the pins out with needle nose pliers. A few of the wires exit the EIS harness just behind the connector such as power, ground, fuel sender and warning light.
The violet wire runs through the harness to the warning light with the other side of the warning light is connected to power. I made sure that the dash is easily removed by disconnecting wires as opposed to having to cut wires to remove it.
The last item to connect is the green wire to the fuel level sending units from the gas tanks. When it gets a little warmer I’ll roll her outside, mount the wings and tanks and then work on routing the fuel sensor wires. I’m not exactly sure where everything ends up so not much I can do with that for now.