Panel/Electrical
Updated 12/26/09



Instrument Panel:

Cutting of the instrument panel was done in the drill press with a $12 General tools circle cutter from the hardware store.  The primary flight instruments had to be shifted to the left an inch or two to allow for the planned radio stack.  Distance between the flight instruments is 3/8". 

It took some experimentation to find a  magnetically undisturbed location for the magnetic compass in the panel .  Once I installed the panel in the plane there was no good place for the compass.  It seems to be disturbed by the rollover bar everywhere on and in the panel (or is it the metal garage door overhead??).  More on this after the plane flies...

Update 4/15/01 -- Was able to successfully swing the compass in its location shown below.  I did this in-flight by flying parallel to north/south and east/west roads and adjusting the compass with a home made brass screwdriver. Several iterations of flying parallel to the roads and adjusting the compass to the correct heading at each of the cardinal headings eventually yielded correct headings within a couple of degrees. Magnetic variation was subtracted out when doing this procedure as the roads are true headings.

Update 3/4/09 -- On the way back from Oshkosh last year I had my second vacuum pump failure.  The pump was a new $700 AEON pump from Sigma Tec which was supposed to last for 2000+ hours (it lasted 200).  They did honor the warranty and EFIS systems have advanced so I removed the entire vacuum system and installed a GRT Sport EFIS. 

Initially I installed the Magnetometer in the empennage.  It is awfully tight back there and I am not as young and flexible as I was in 2000 when the plane was constructed.   Two problems popped up with this location... One was the canopy frame, when open, caused a large magnetic disturbance.  The other was bad RF interference when transmitting on the comm. radio causing as much as a thirty degree swing in the magnetic heading!!!

I moved the magnetometer into the wingtip.  Understatement: Installing a cable from the instrument panel to the wingtip in flying airplane is difficult.  The junction between the wing and the fuselage is particularly tricky.  Fortunately the magnetometer behaves better there and is much easier to get into the required alignment with the EFIS unit.

I  also installed a 3.5 amp/hour battery just ahead of the left landing gear box as an emergency backup for the EFIS.  It is charged through a diode and resistor when the avionics bus is on.  The diode prevents it from discharging into the avionics bus and the resistor limits the charging to a trickle.


Update 12/26/09 -- While the GRT Sport EFIS had a great feature set and excellent customer support, I was unhappy with the performance of the attitude indicator.  It had an annoying response lag and occasionally showed a roll and pitch errors of around 3 degrees.  The screen update rate was only 6 Hz.  So far the AFS attitude indication has proven superior.   The screen update  rate is 30Hz.

The Nav122 does not output a CDI signal that is compatible with the EFIS so I replaced it with a Garmin SL30 (or should I call it the $L30).  I mounted the comm antenna on the turtle deck inside the canopy.  It just barely fits there and adds no drag.

A Test Installation of the Instrument Panel

Evolution of an Instrument Panel

12/26/09

Added:
Flightcom Intercom
Comm Select Switch

Replaced:
GRT Sport EFIS with AFS 3400 SV
Narco Nav122D Nav System with Garmin SL30
Vans Tachometer With Flight Data Systems T-30 Tachometer

Removed:
Second GPS antenna (New EFIS has no internal GPS)
EFIS Standby Power Switch (New EFIS has internal backup battery)





3/4/09

Added:
GRT Sport EFIS
IFR Approach Annunciation Lights
EFIS Standby Power Switch

Replaced:
GX65 Replaced with GX60 - Adds GPS approach capibility
AFP-30 Programmer moved below panel - not necessary to have access in flight
LC-40e Panel Dimmer with LC-50 Dimmer - Allow dimming of the whole panel with one knob

Removed:
Vacuum AI - Replaced with EFIS
Vacuum DG - Replaced with EFIS
Suction Gauge - Replaced with EFIS
VSI - Replaced with EFIS
Marker Beacon Receiver - Did not work very well and not often needed with the moving map display
Voltmeter - Duplicated in GT-50 and EFIS
p1 8/1/06

Added:
Flight Data Systems GT-50 G-Meter/Clock/Timer
Monroy ATD-300 Traffic Avoidance Unit
Post light to Illuminate Switches
Master Bright Switch for LC-40e Light Dimming System
DB-9 Connector for Programming the AFP-30
Zeller Canopy Holder

Replaced:
Cabin Vent outlet with High quality Model - Plastic units were leaky

Removed:
Falcon G-Meter - Replaced with GT-50
Astrotech Clock/Timer - Replaced with GT-50
Panel 10/1/03

Added:
Flight Data Systems AFP-30 Computer
Falcon G-Meter
KS Avionics Tetra II CHT/EGT
Altrak Altitude Autopilot
Power for Noise Canceling Headsets
Magnetic Deviation Card


Replaced:
Altimeter - Falcon Altimeter did not pass IFR certification even though it was new
Directional Gyro - Falcon unit tumbled and precessed
Attitude Indicator - Used original unit needed an overhaul
Manifold Pressure - Original filled up with fuel!,  New unit has a diaphram
Carb Heat control - Original unit friciton device failed
Cabin Heat Control - Original had no friction device

Removed:
Westach EGT/CHT - Poor quality/ Replaced with KS Avionics unit
Westach OAT - Poor quality/ Replaced with KS Avionics unit


p2
1/21/01

Just weeks before the first flight...

Electrical Notes:

I am using the Vans electrical kit.  It seems easier than designing a system from scratch.  The drawings are a HUGE help and it was very useful to order them long ago providing time for digestion.  The only other option considered was using Bob Nuckolls system design.

There are two tricky bits to the system.  Ones is wiring retard breaker magnetos.  The other is providing overvoltage protection for the 40 amp internally regulated Nippon Denso alternator.  Both of these problems were solved by accessing the Aeroelectric Connection website and downloading drawings from there.

I am trying to leave enough slack in the wiring so the panel can be lowered down the next set of attach screws for service and modifications.  We'll see if this works or is useful.


Here is the guts of the Vans Electrical kit design in the early stages of wiring.  The terminal strip on the bulkhead is for the trim and flap relays.  Also, I cut an access hole visible on the right

The radio rack had to be made from .032" 4130 steel bent into a 90° angle because the edge distance was not adequate to use .063 alum angle.  The angle dimensions are 3/8" (where it attaches to the panel) by 3/4" (attaching to the radio cans).  The rack is tied to the forward bulkhead with .063" angle in a manner similar to the battery box to firewall attachment.  It seems  quite sturdy.
The ELT installation with its antenna visible on the left

This is a nifty place to put the panel flood lights.  These eyeball lights do a great job and are relatively inexpensive.  They can be rotated down and used as a map lights too!
Extras:

I went a little crazy with panel lighting.  It consists of post lights for the flight instruments,  two map/flood lights shown on the left and the internal lighting on the engine instruments and radios.  The rear seat passenger also has a map light with its own dimmer.  Rich designed a four channel microprocessor controlled light dimmer nicknamed the "Dimwit" so each group of lights can be controlled separately.  More on the "Dimwit" as it moves out of the beta stage...

The rear seat has everything needed to fly.  This includes flap control, elevator trim, radio frequency toggle, transponder ident, throttle and rudders.  The trim and flap relays and fancy stick grips make this possible.

Update 4/10/01
- The "Dimwit" seems to be working pretty well. I have actually flown at night with it now! 

Update 2/26/04 - We have re-engineered and renamed the "Dimwit" the LC-40 Lighting Controller.  Click the picture for details. It sells for $89!


LC-40

Update 8/3/06 - By popular demand we produced the LC-40e ($109) enclosed dimming system. We have sold over 500 units!



LC-40e

Update 3/4/09 - We have now created the ultimate Dimmer, the LC-50.  Click on image for more information.