The Panel

First stage in panel planning was deciding what type of gauges I want on the thing. That was pretty easy.

Altimeter, Airspeed and Compass for general flying knowledge.

CHT, EGT, Fuel Quantity, Tach, and Hour Meter for engine monitoring and safety.

The next step was even harder. A nice instrument, called an EIS, is available, which tells most everything but airspeed, all in one box. Nice, and about on the par with the mechanical stuff. I even planned it out at one time. However, after much thought, I decided to go with the mechanical, analog stuff. This was good, as my motor choice probably would not run the fuel pump, fuel gauge, radio, GPS and an EIS.

My first instrument purchased was a Westach fuel sender and gauge. Cutting the probe to around 7 inches, It was calibrated and installed in the top center of the fuel tank. It will be plugged into the fuel gauge and the electrical supply. Once mounted, the sender is stuck to the fuel tank for good, unless it breaks and needs to be pried loose.

I Cut the panel from 1/4" mahogany plywood, left from scrap. I cut two angle brackets from one inch aluminum angle, eighth inch thick, and used AN-7 bolts (i think) to attach the panel one inch forward of station two. On the left side I mounted three switches. The first is the kill switch, and with the canopy closed it is hard to accidentally switch off, but it is possible. The next is a fuel pump switch, as the fuel pump my be operated independently of the rest of the electrical system. That switch is also protected by the canopy. The last one is a master switch, which turns on the power to the radio, GPS, trim switch, and fuel level and a few other gauges. To the right and above the switches is fuel level, and under it is a single 15 amp fuse holder, 15 amps being the limit of the rectifier. On the far right side, I mounted the primer plunger. Afterwards, I realized it will be a little awkward in using while outside the plane, but I had my reasons. I wanted all the electrical stuff on one side, all the air operated stuff in the middle, and the fuel lines on the other. Due to the fact I have decided to go with a Hirth engine and electric start, this worry has been eliminated. Prime from inside plane, start from inside.

First gauge and switches mounted:

See the motor page for another view of the panel. At this point, the two pages sort of merge, as the motor stuff and panel are interdependent. Below is a picture of the back of the first switches, and the red LED which lights in case of a regulator failure.

Although it is technically not part of the panel (it is hooked to the canopy), the GPS was mounted next. Using two pieces of angle aluminum, I made a cheap mount for my Magellan GPS 310. I screwed up, and put the wrong size screw in the back, which got stuck. Upon removing it, the little brass ferrule came out. I thought I had really messed up, but it turns out the hole that was left was exactly the right size for a 3/16” inch bolt to fit in tightly. I used a 1 and ½” carriage bolt, but cut the end off and slotted it with my Dremel. I screwed the bolt in a little (the inside of the case was about 3/16” deep, and then there was another piece of plastic so I did not worry about shorting anything out). I slid the external power adapter over the screw (after drilling its hole out to 3/16”), and put a faucet o-ring between the aluminum piece and the power adapter. Enough screw was left sticking out so I could put on a wing nut. The reason for the wing nut is simple: I can remove the wing nut, and the GPS comes off the power adapter. It will run on its batteries and I can use it outside the plane. After placing the windshield, I found the GPS was in the way, and extended the aluminum bracket. With a nylon washer underneath, the bracket will swing out of the way if I am not using the GPS. The power adapter has a small black box in-line, which I mounted under the swing-up canopy. The black box converts the plane’s 12 volts to three volts for the GPS.

The next panel item to be mounted is the Tiny Tach combination hour meter (when engine is off), and tachometer (when engine is running). Not having purchased the remaining instruments (airspeed, altimeter, and egt-cht), I am not sure where to put it. I am having second thoughts about the compass. The GPS blocks my view to part of the panel, so I am not sure how much room will be left over, and the panel is so tight, I worry about interference from nearby electrical gauges. I could mount the compass between the airspeed and altimeter, where it’s view is blocked by the GPS. This way, if the GPS goes down, it will swing out of the way and I can see the compass to navigate.

No pictures as of yet, but I have mounted the Tiny-Tach. It fits perfectly above the primer knob. I have also determined what to do with the rest of the instruments. Using cutout guides from the aircraft spruce and specialty catalog (which I laminated for durability), I decided to put the Airspeed Indicator just to the left of the Area blocked by the GPS. The Altimeter goes just to the right of it, leaving approximately three inches in the middle. At the bottom of the panel, in full view, will be the engine instrument, the EGT-CHT combo. Behind the GPS will be a little blank. I could put something else there, as there will be a little room, but I am not sure what. The GPS will still swing out of the way if not needed, but will not reveal anything special. A compass would fit nicely there, but above the CHT-EGT, I worry about magnetic interference. Still, it could save a little headroom in the event of a forced landing.
I originally planned to install the electric trim switch on the panel, but I started thinking in terms of resource management. I know those are big words for ultralights, but I wanted everything easy to get to. My throttle is mounted on the left side of the fuselage opening, in front of the latch. Right beside it, I mounted the trim toggle switch. I can run the throttle and trim without moving my left hand. All three electrical switches are also in easy reach of my left hand, which leaves the right hand free to fly the plane. Hooked to the stick will be the hand brake. Pictures are forthcoming.
After purchasing the ”big three” instruments, the airspeed, altimeter, and CHT-EGT combo, I had to cut up the panel to fit stuff. Unfortunately, the cutouts from aircraft spruce did not match the instruments. They were slightly smaller than my instruments, so the pre-drilled mounting holes I made did not work. Fretting, I fitted the instruments up and drilled new holes. I thought I would have to scrap the panel and start over, and I would have, but I had no extra wood big enough. After sticking the instruments in the holes, the panel looked pretty good. From the back it looks terrible, with a bunch of extra holes in it. They are covered up in front though, so no big deal. The Altimeter is about a quarter inch lower than the Airspeed Indicator, but otherwise I like it. I painted it with two coats of paint, and it awaits the purchase of screws to hold the instruments in place.
The biggest problem is the cheap altimeter I bought. Well, not cheap, just not as expensive as it could have been. It is a non-sensitive type, zero to ten-thousand feet, with a kolsman window. The opening in the back was not tapped for the 1/8 npt pipe connector I had planned to use to connect it to the static line. I had spent a lot of time, not to mention twenty bucks for a static port, running a line and preparing everything. I also had a nylon 1/8 npt pipe fitting for it. Using an x-acto hobby knife and my dremel, I sanded of the threads, and then scraped off the nylon fuzz that was left. Once the threads were scraped off, I pushed it into the back of the Altimeter. It is still a tight fit, and seems to work well. Once the panel is put back in place, the airspeed and altimeter will share the static line. I still have to run a pitot line, but it should not be much of a problem.
Done, Done, Done! It is March 26, and I pronounce the panel complete in all respects. Pictures will be forthcoming. Took lots today, and hopefully they will be worthwhile. I mounted all the instruments to the panel, and replaced it on the plane. I even hooked up a power supply to the regulator and gave the switches a brief test. It all worked as planned, after a slight hitch. The electric fuel pump sounds like a machine gun. I only hope that it is for two reasons: Number one: It is running dry now, as I have not put any fuel in the tank. Number two: There was an abscence of me in the fuselage, which should help muffle the sound. Right now it is as if the forward fuselage is a guitar box with a vibrating pager dropped inside. Number three: There is no extraordinarily loud two-stroke to cover up the sound.
As a final problem, my master switch was upside down. When I thought it was on, it was off, and vice versa. Not good. I finally figured it out, loosened the wires, and fixed it. My fuel level gauge needed a little tweak, but after it was all fixed, everything looked fine. I replaced my diminutive and fragile-looking starter switch with a more robust (read: expensive) metal-cased pushbutton switch. It cost me eight bucks for a switch, but it is heavy duty and looks good. The only thing I have yet to hook up is my electric trim servo. I forgot to buy the screws at the hardware store. Next time I should finish all the electrical work that I can without the engine. I have trim wires in place, but no servo. The empennage is complete too.

After long last, here is the panel, minus only the labels for switches and the light. Everything installed and ready, except for the sensors. In the left picture you can see (from left to right); the three main switches. Mags, Fuel Pump/Starter, and Main (for gauges/radio), above is the big round start switch. Under the fuel gauge is the fuse holder. Then we have Altimeter, EGT/CHT combo, and Airspeed. To their right is the Tiny-Tach, and the primer handle. In the foreground, near the left bottom of the frame is the throttle handle, and the little switch immediately to its left is the elevator trim switch.  In the left picture is the rear of the panel. You can see the backs of the gauges and the shared static line (clear), as well as the regulator, primer lines, and fuel lines coming up through the top deck. Their are two lines, one for the pulse driven pump and one for the electric pump. They connect just after the pulse-driven fuel pump at the firewall. At the bottom of the picture is the underside of the swing-over canopy. On it you can see how I mounted the power converter box for the GPS. It turns the planes 12 volts into 3 for the GPS. There is also a connector in the line, so I can disconnect the box, and remove the canopy screws, thereby removing the canopy.

After seeing how nice other people's panels looked compared to mine, and having not much money to do anything else with the plane right now, I decided to redesign my panel. Although the wood looks nice, the fact the instruments are mounted in front and are not lined up well makes the panel look, for lack of a better word, ugly.

The first step was deciding how to best fix the problem. I did not have a good piece of quarter inch wood to make a panel, but I did have a nice sixteenth inch thick piece. First I removed all the instruments and disconnected wiring and tubes. Then I cut out where the old instruments had been mounted. Once done, I sanded the front clean, and laminated my piece of sixteenth inch plywood onto it. Then I carefully measured spots for the instruments and drilled holes. I also learned a hole saw trick. Using a regular pilot bit lets the hole saw chatter around and make the hole uneven. My fuel gauge hole is off-center because of it. However... When I used a longer pilot bit, a twelve inch one, where only the first three inches actually has the "twisty bit", my holes came out much nicer. When a solid piece of metal is rotating in the hole,  it prevents the chattering. The toughest job was cutting the square hole for the tiny-tack, because I wanted it flush-mounted like the other instruments.

Once laminated and dried, with the staples pulled, I spread poly-brush over the wood panel. It took three layers and some reducer to close all the pinholes. Poly-Brush does not work as well on bare wood, they said, but I wanted my instrument panel to match the fabric which will surround the edge of the cockpit. I brushed poly-spray silver on as well, to make it easier on myself instead of having to clean the spray gun. After sanding, I finished up with several coats of sprayed-on poly tone, in Lakeland Blue to match the rest of the plane. I never really did let it dry all the way. I sprayed on a wet coat, waited twenty minutes, and sprayed again, and again, until I liked the look. I think I put on four coats. But there are no pinholes, and the wood is well sealed. I know you cant treat fabric that way, but the panel looks nice. I then mounted instruments, using brass screws and nuts from ace hardware, along with a generous amount of itty bitty rubber o-rings for shock mounting. Most instruments have three o-rings per screw. From the front to the back: Screw head, washer, o-ring, panel wood, o-ring, instrument, o-ring, washer, nut. Hopefully it will help. I should be able to develop that 'seat-of-the-pants' flying ability by the time my analog gauges crap out.

 I only ran into one problem. My switches did not really have enough room, so I had to cram them in after painting. They look okay, but not great. I know the compass isn't in the greatest place, above the cht-egt meter, but normally it will be obscured by the GPS hanging down. I got the compass cheap, and only intend to use it for general direction finding as course holding, if the GPS craps out. I will be able to swing the GPS out of the way and look at compass numbers. I am not concerned about it being dead accurate, as long as I can use it to fly straight ahead. I do intend to check its function though, and fill out a proper calibration card, which should mount under the airspeed indicator.