Engine Control Unit (ECU) takes Shape (July, 30th, 2005)

I mentioned it a few times before: my aviation engine most probably will have fuel injection and digital ignition control. The last few days I assembled an ECU kit (Megasquirt V2.2).

37-pin main connector and manifold pressure input (left). 9-pin serial connector (where laptop connects to the ECU for diagnostic purposes) and LED status lights (right)

In front the 'stimulator board'. Engine sensor signals are simulated by potentiometers. All functions can be tested this way

The inside of the ECU. The large chip is a Motorola 8-bit microcontroller. The MAP pressure sender is located on the bottom side of the board. On the very upper right the two power MOSFETs (screwed to the side panel) which will drive the fuel injectors.

Two screens of the Megsuirt PC tunig software program.

The assembly instructions ot the Megasuirt were very detailed and instructive. As far as I can tell the unit worked flawlessly on the first try.

Next steps are to upgrade the CPU for the ignition control.

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Landing Mishap (June, 19th, 2005)

Had a landing mishap today. Too low, too much speed. Unfortunately the landing gear were my own legs (chute landing after a skydive)

Both right lower legbones broken. Massive titianium bar inserted into shinbone (did they forget the self-locking nuts??). Seems that I'm grounded from all flying/jumping/building for the next two months (at least).

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Needed a Change from House & Gardening (May, 18th, 2005)

This is the new toy (Dragonfly RC heli). Available for a handful $ from Hong-Kong. It's ready-to-fly. All included (NMH-batteries, charger, 4-channel remote control, interface cable to connect the RC to a laptop to run a heli sim before crashing the real thing :-)). Rotor diameter is 510mm, length 470mm, MTOW 350g.

A full-featured heli, maneuvrable in all four(?) axis. Cabin shell is removed.

The rotorhead.

Tailrotor is driven by an electric motor - a clever idea.

Aaaand now THE question: How does it fly? - Well, - aehm - driving a heli is no childplay :-)) After experimenting with trim settings for one battery charge now I can fly 2 ft above the ground for about 5 seconds (before I crash-land the thing). There is a tendency to roll over to one side - hard to manage this. If piloting a real heli is a class for itself then piloting a RC heli where perspective always changes (and controls are mirrored) is still another thing. Anyway, lots of fun (and the machine is almost indestructible).

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Left Aileron (May, 12th, 2005)

The left aileron is now completely closed and attached to the wing (using the Sonex-favoured piano-hinge method)

Miraculously the aileron fit is nerly perfect (I rarely accomplish such a thing on the first try...). The aileron should be slightly overbalanced - looks perfect. The aileron closing rib is a 3-d part with all odd bend angles- not so simple to make as it looks

This is how the counterweight fits in the wing containement. Sor safety reasons I made the lead-weight a bit longer as shown on the plans and - surprise - it is just right.

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Ignition (May, 11th, 2005)

The Ford EDIS-4 ignition parts arrived today. They're from a Ford Excort from the early 90's.

The ignition wires I most probably won't re-use, however the plugs on the coil side are unique and made in one piece - this may become a problem. The coil box (center) also came wit a capacitor (above the coil block). The control box (center bottom) also will provide sparks if the connection to the ECU is lost (static 10 Deg. BTD in 'limphome mode'). At right the 32-1 index gear and geartooth sender. The strange box at top right seems to be a g-force operated cutoff switch - most probably it won't find its way into my bird :-)

Still undecided is how to attach the sprocket wheel on the Revmaster crank. I like to avoid removal of the prop flange (again).