The linear actuator used for electric flaperon control in 254R is a Thomson/Danaher Motion Electrak Q050 DE12Q17W42-02FPM3HN, purchased in 2006. The specifics in that lengthy "DE..." number include order specs for 12VDC, 2" stroke, internal limit switches, a particular speed and torque, orientation of mounting pins, and internal position-sensing potentiometer. I bought mine through the Richards Co., a Thomson/Danaher distributor.

At this writing (12/08) Danaher does not seem to use the "Q" designation any more and instead appears to just have the "E050" versions. However, the same specifications are apparently still available in that nomenclature. The current ordering specs and wiring diagram PDF files (see p. 1 in each) are attached below for further reference.

Photos and info about the linear actuator design and installation work in this airplane can be found by using the search box, above left, and searching on "actuator".

A number of people have asked about specifics of the linear actuator used for electric flaperon control in N254MR. After digging around a bit, I located the specs and model number. It is a Thomson/Danaher Motion Electrak Q050 -- DE12Q17W42-02FPM3HN. Additional details are available in the Library, Project Documents, Design, Electrical section. Photos and info about the linear actuator design and installation work in this airplane can be found by using the search box, above left, and searching on "actuator".

One of the cool features of the EI SC-5 clock is that if you provide one of its special inputs with +12VDC when the engine starts, the clock keeps a non-resettable total time, like a Hobbes. More importantly, if it's given power when the engine starts, it will automagically start the UP timer, providing an automatic flight timer -- very handy for fuel management, not to mention logging. I already have, and want to keep, a traditional Hobbes meter. It's the automatic flight timer function that I want to have.

Of course, the logic for "engine ON" is normally provided by the N.O. contacts of the oil pressure switch. (It would be possible to derive this from the N.C. contacts as well, but they are reserved for the critical oil pressure warning function only.) When the engine starts, and the N.O. switch closes, the N.O. contacts pull +12VDC coming through the regular Hobbes meter to ground, completing the circuit that energizes the Hobbes. Unfortunately, there is no way to directly switch +12VDC ON, because the far side of the N.O. switch goes to ground. So....

I've made the super duper oil pressure switch multi-I/O inverting relay (MIOIR) circuit. The relay coil is wired in parallel with the regular Hobbes circuit, so the relay coil is also energized by completion of the circuit provided by the oil pressure switch's N.O. contact. Voila! Then the load contacts of the relay can then be used to turn on +12VDC power to the clock. It's so neat that I decided to bring out (2) wires for each of the available relay states to the D-sub connector, specifically, two wires that switch power ON, and two that switch it OFF. There won't be a shortage of engine ON/OFF logic now! The downstream sides of both the Hobbes and the relay coil are protected by a dual Schottky diode to avoid back feeding the Hobbes, which is polarity sensitive. The MIOIR looks like this:

The only downside to this arrangement is that, because the relay coil and the power to the relay load contacts are in parallel with the Hobbes (+) feed, they also run on the same 3A fuse that powers the Hobbes. The priority among these things is the regular Hobbes. To make sure that some load on the relay load contacts, like the clock power, doesn't blow the common 3A fuse, I'll put a smaller 1A inline fuse in the wire going to the clock -- and any other small loads I may want to hook up to this gizmo in the future. [I'll add a schematic here later. It really does work. ]

Photo of the oil pressure switch N.O. contact inverting relay box, which will allow delivery of +12VDC to the EI SC-5 clock's engine monitor circuit, which requires logical positive voltage when the oil pressure's N.O. contact closes to ground. Interestingly, in the relay's N.O. position, the other pole of the relay delivers +12VDC output in the N.O. position too, which is inverse from the O.P. warn circuit. In other words, when oil pressure develops, this relay can both turn +12VDC circuits ON via its N.O contact (like the EI SC-5 engine monitor line) as well as turn +12VDC OFF via its N.C. contact (ON with no oil pressure), if needed. Importantly, although the relay is triggered by the B&C pressure switch, it does the latter independently of the critical primary oil pressure warning circuit, which is the only thing on the B&C pressure switches N.C. circuit. The relay is a HASCO SSD-103PU-12 SPDT 3A 12VDC with a nominal 320 ohm coil, that draws a measured 39ma current.

This picture shows, clockwise from top, 1) a "hobbyist" LED/resistor/wires assembly from SuperBrightLEDs.com, 2) another one where the resistor and red wire have snapped off the LED bulb, 3) red Fresnel mounting lens, 4) green Fresnel mounting lens, 5) black retaining rings, 6) white spacer rings, 7) one of the fully encased LED assemblies from Radio Shack, which does mount relatively flush, and 8) one of the fully encased LED assemblies from SteinAir. The latter two alternatives are mechanically robust, but suffer from a relatively narrow viewing angle, and the SteinAir model is not flush.

 [...a work in progress, as I plan to add more photos, etc.]

Friend and fellow Rebel builder Terry Dazey was the latest of several people to inquire about details of the LED indicators. My response below covers most of the details of the why, what, and how. Terry asked:

Maybe I missed a link in your web Rebel photo description, but I am curious what is the part number and where did you purchased the small, colored LED annunciator lights as shown on your left wing panel? I like 'em.

Well, that's a story. After way too much cogitation and research, and after trying several things, I ended up with the design and parts I did because I had the following requirements:

A) I wanted a semi-flush appearance, B) I wanted wide angle visibility, C) I wanted a couple of the LED's to be self-blinking, and D) I wanted them to be replaceable, because even LED's do sometimes burn out.

Although these goals were met, the tradeoff, at least as I did it, was to give up getting out-of-the-box-robust mechanical strength, and I had to beef up the parts I has chosen with lots of heat shrink. In detail....

First, the basics: in a nominal +12 VDC circuit (more likely north of 13.8 VDC with an alternator running) an LED must have a resistor ahead of the LED, in series with it, to act as a current limiter. Without the limiting resistor, the internal resistance of an LED is too small to self-regulate at that voltage, and excess current will promptly burn out the LED. LED's come in different colors, which are derived through use of different elements (metals and minerals) in the LED. The current handling (internal resistance) characteristics of the different materials also vary, which means different colors of LED's will often require different values of external resistors. Common values range from 470 ohms to 1K ohms or more.

A bare LED has small stiff wires coming out of a plastic bulb. The wires are fragile, and can be easily broken off where they enter the hard bulb. It's not easy to solder resistors on one of these wires without breaking it, or overheating the LED, much less solder a longer wire onto the resistor. Consequently, manufacturers have come up with various standard, and not so standard ways to mount the fragile LED wire leads, including use of external ceramic "sockets" into which the bare LED wires are plugged, and encasing the whole thing is a larger volume of plastic, etc. In addition, there are different ways the physical mounting or encasing can be built to include the necessary (at 13.8 VDC) resistor. Most amateur builders will not buy bare LED's, but rather one of these kinds of preformed, pre-wired LED assemblies that include at least a resistor and extended wires. [See photo below for views of the parts I used, as well as a couple alternatives.]

I used the preformed "hobbyist" 5MM LED assemblies available in various colors from SuperBrightLEDs. The trouble with those is mechanical -- the resistor is soldered right onto one of the stiff and fragile LED leads, then attached to longer flexible stranded hookup wire. The resistor and hookup wires continue to hang onto the very fragile junction between themselves and the glass "bulb" of the LED -- there is no external casing to cover and connect both the bare lead, and the resistor and stranded hookup wire extensions. Until the LED assemblies I chose are beefed up with multiple layers of heat shrink, such that I could finally enclosed both the mount (see below) and the heat shrink laden wires together as one unit -- the fragility remains. SuperBrightLED's pre-wired LED assemblies include blinking RED ones. (http://allelectonics.com also has blinking ones in other colors.)

Now for the assembly. Looking at the edge of the panel, with the finish side to the left, and proceeding left to right, first there is the plastic, cylindrical (Fresnel) lens, cylindrically shaped with one end open. The lens "cylinder" goes through the panel opening, and snaps in place. On the back side of the panel, a white plastic ring "spacer" is slipped over the lens barrel. It's sole purpose is to take up space. (See photo below) Then the LED assembly (LED, resistor & extension wires) is gently pressed into the back of the lens barrel. Fnally, the black plastic ring retainer is press fit over the wires and the last part of the lens barrel, and clamps the lens around the LED body, locking it in place so it won't slide out of the lens barrel. Additional layers of heat shrink are then added carefully, until the fragile leads are protected all the way from LED body to the extended hookup wires. It's good to order several extra LED's of each color... some may break in this process, and they're not terribly expensive.

The LED mounting pieces came from Mouser Electronics. Representative part numbers are:

Red lens     593-3000R (other colors have a different last letter)
White spacer ring     593-SPC125
Black plastic retainer ring     593-RNG268

All these individual parts are very cheap. Get extras. The biggest expense is shipping. I should also note that it's not advisable to use a plain white LED behind these colored lenses. A plain white LED will tend to wash out the color of the lens a great deal. Better to match the LED color with the same lens color. All that having been said, as it turned out, the only place I needed blinkers was the oil pressure and stuck starter LED's, both RED.

There are several other, more out-of-the-box-robust assemblies available, including ones from SteinAir, RadioShack, etc. Unfortunately, the LED's with hard plastic cases from SteinAir sit quite high off the panel, definitely not flush, and have a limited viewing angle. Radio Shack has some nice plastic-encased LED's that are nearly flush, but they also have a narrow viewing angle. I wanted the co-pilot to have almost as good a view of these lights, especially the annunciator LED's above the left EFIS, as the pilot. That requirement led to the Fresnel lenses I used -- which also happened to lie very flush. The photo below shows a collection of the parts I used, and the RadioShack and SteinAir alternative styles. Of course, there are others too.

This picture shows, clockwise from top, 1) a "hobbyist" LED/resistor/wires assembly from SuperBrightLEDs.com, 2) another one where the resistor and red wire have snapped off the LED bulb, 3) red Fresnel mounting lens, 4) green Fresnel mounting lens, 5) black retaining rings, 6) white spacer rings, 7) one of the fully encased LED assemblies from Radio Shack, which does mount relatively flush, and 8) one of the fully encased LED assemblies from SteinAir. The latter two alternatives are mechanically robust, but suffer from a relatively narrow viewing angle, and the SteinAir model is not flush.

For more info, search on "LED" on the web site. Most of the relevant info will be on the first page of search results.

Several hours of testing the left panel functions have produced good results. One switch was mis-wired (easily fixed) and there is a short somewhere in the wire between the A/P switch and the A/P harness D-sub connector. I'll open the D-sub hood to track it down, which shouldn't be too hard. I haven't yet tested the low voltage and overvoltage protection circuitry, but on all other circuits, DC power is showing up when and where it's supposed to show up, including the oil pressure switch, fuel tank gauges, elevator trim actuator, etc. The lighting circuits, dimmers, and LED indicators work, including the LED indicator wires going to the center panel. Load stress testing will be done after avionics and other gear are installed.

There were a couple of false starts when something didn't seem to work as designed at first -- resulting in considerable head scratching -- before I realized I needed not one, but two or even three fuses in place to allow that function to work as it should. I burned several fuses, but only because it's not easy for my clumsy fingers to place the VOM probes in some of the tight spots -- like the back of the radio stack -- without shorting out to nearby metal.  No problem, that's why I was using small fuses! It was great to be able to print out the Fuse Assignments page of the electrical spreadsheet, as it was an excellent guide and logging tool for these tasks.

There were surprises, mostly of the good kind. The first circuit I tested on the MAIN BUS was the START button -- just because it's at the top of a column of fuses. The starter contactor clunked ON just fine, but I was so focused on the voltmeter connected to the output that I was momentarily very surprised to see the associated red LED flashing away -- just like it's supposed to! What a fine sight. (That LED indicates the starter contactor is activated. If it continues to flash after the START button is released, it would indicate a stuck or otherwise faulty contactor, or toggle switch.) This momentary astonishment upon seeing an LED suddenly fire up when it was supposed to happened several times. Great fun! 

The bottom line is that after planning this over a period of years, followed by many months of building, not to mention tweaking and re-building, it is incredibly satisfying to find almost everything working just as it should on the first go.

An updated electrical spreadsheet has been posted. New items, reflecting recent work, include quite a bit more on panel interconnects, updated details about flap controller & switch(s) installs, and various kinds of miscellaneous notes -- most about wire terminations, why and where they are.

The latest electrical spreadsheet is up. I can't believe I haven't posted a current edition here since July 5th! Lots has changed since then -- so much so that this is really a "systems" reference at this point, going beyond just electrical, per se. New items include a tab for relay shelf pin-outs, and a general notes tab, with oodles of essential info about items like unused, stubbed off wires and where they're located in case someone wants to implement them in the future. Other notes cover the network switch wiring, how to remove the XM receiver, etc. The newest tab, still empty, will hold pinouts for the various panel interconnects under construction right now. As always, this is an imperfect work in progress.