next topic »

[on:]

My race team and I are working on turning a Cessna 310 twin engine aircraft into a road race car. We've gutted the Cessna and shoved a Toyota Van wagon into it.  I'm working on getting the flight instrument panel to work with the ECM from the Toyota (tach / speed / temp), but that's not what I'm here for. On each side of the fuselage,  we have "winglets" that extend about 20 inches.  These winglets have the factory wing flaps attached.  We also have to put a small nose gear in so that if we brake hard, it stops the plane from flipping forward.

Functionally for the flap would follow like this:  Flap up indicator light is on.  Driver / Pilot / Racer pushes the existing flaps switch down.  Motor actuates the existing arm in the winglet and the flaps drop.  When the winglet flap starts to drop, a switch is released and the Flap up indicator turns off.  When the flap is all the way down, a switch is depressed and the flap down indicator is now lit.  Reverse it for bringing the flap up.

I've never used Arduino. Does this sound like something I should do with Arduino or have I turned into a nutter? Would Arduino just be overkill? I'm looking for guidance on the parts I would need, and eventually the programming.  I've done some programming (mainly modifying existing source code and recompiling), but nothing from scratch.

Thanks!

[Reply #1 on:]

You should be able to do it with nothing but a couple of microswitches, each leading to its own LED.

[Reply #2 on:]

So, I'd use those same switches as my cut-offs for the motor as well?  (Motor stops when flaps are up or down)

[Reply #3 on:]

Oh, I was under the impression that you were going to use original controls for the flaps. Why not?

Microswitches can't handle currents required by such motors, but could be used to send the signal.

[Reply #4 on:]

The original Cessna did not use a uC, why add one now?
On single engine planes, like the C177, the original flap switches/limit switches under the panel I believe drive the motor directly, and do not drive a power transistor or something elsewhere up in the wing.
You can download a wiring diagram for the C310 and confirm. Or use an extension cord with your multimeter and confirm.

[Reply #5 on:]

All the existing wiring and motors were gutted in the name of making it lighter for the road race.  So now we are adding in the fun little stuff to show off.  I'm putting all the instrument panels (with factory gauges, switches, fake radio dials, and lighting).  The motors that used to drive the flaps are gone, but the cable pulleys are still there, so I can tie into those and maybe replace the steel cable if necessary.

I'm researching reversible 24v motors to see if it's feasible.  Since the flaps will operate in unison, I might be able to use a single motor.

I'm still trying to decide if i should use Arduino and relays to drive the motor and indicators or just go "old school".

[Reply #6 on:]

Here's the build if anyone is interested... http://www.speedycop.com/spirit-of-lemons.html

[Reply #7 on:]

It sounds like the only thing missing is a "flaps down" indicator.  Right?   I agree, you don't need to program an Arduino for that.

So, I'd use those same switches as my cut-offs for the motor as well?

Maybe...  It depends on how it's wired.    You should be able to "tap into" that switch's logic and possibly use a transistor as an inverter to turn the light on when the motor goes off.  You may need some additional logic to hold the indicator on, and then to keep it off when the motor is reversed. 

There are various logic circuits such as "and gates", "or gates", "inverters", and "flip-flops".   These don't need to be programmed with software.   Their function (and combined function) depends on how they are wired.    If the logic is fairly simple, and there's no "counting" or math, logic chips are usually easier.
When the circuit starts getting complicated, it becomes easier to do it in software (with a microcontroller).   

Note that most logic circuitry (as well as the Arduino) runs off 5 Volts.    "Converting" a 12V signal from  a switch down to 5V only takes a couple of resistors.   But, converting up to run a 12V lamp (if you don't want to use an LED) requires something like a MOSFET or transistor or relay.

Or, maybe there's an unused terminal on the switch (if it has normally-open and normaly-closed terminals).

Or, you may need to use an additional similar switch.

[Reply #8 on:]

Ok, I see some conflicting interests here. On one hand you strip the Cessna of everything to save on mass, yet now you want to install some of the almost-original functionality back into it hoping to impress the audience. Do you want to win the race or just have fun?
Screw the arduino, motors, MOSFETs and transistors. Install a cable and pull the flaps by hand so you can wave at the audience while tipping over in a tight corner.

If you really want arduino, put some LEDs on the plane. Heck, put a whole bunch of them and set them up for an epilepsy inducing choreography. Audience is cheap and will be impress a lot more with shiny LEDs than flaps on an airplane.

Are you using the Cessna engine to power that thing?

[Reply #9 on:]

It's powered by a Toyota Van wagon....

In this type of race, it's not the number of laps that make you win.  (although having a lot of laps does help).  There was no way to get the Toyota chassis, suspension, engine, and all that into the plane without gutting it. We have to put a roll cage in it too. (Safety 2nd!)

Adding a little bit of basics back to the plane for "showmanship" isn't the worst thing. We need lots of laps, and we'll have lots of fun too.

It's starting to seem like this isn't an Arduino setup.  Between some basic circuits, relays, and the existing switches / indicators, it can come back to life as long as i can get the motors I need.  I'll have to look around and see what's available.

[Reply #10 on:]

The winglets and any other aerofoils will be designed to give LIFT which is the last thing you want in a car. You many want to do some re-design so that they give DOWN FORCE which helps hold the car on the road.

Mark

[Reply #11 on:]

The below switch may be all that is needed.

http://www.radioshack.com/product/index.jsp?productId=2062530

[Reply #12 on:]

The below switch may be all that is needed.

http://www.radioshack.com/product/index.jsp?productId=2062530

Right. See http://www.robotroom.com/DPDT-Bidirectional-Motor-Switch.html for how to put that together with the limit switches (scroll down to the last schematic). You would have your LEDs light up by connecting them to the normally open side of the limit switches.

[Reply #13 on:]

Switch setup from a while back.

[Reply #14 on:]

Right. See http://www.robotroom.com/DPDT-Bidirectional-Motor-Switch.html for how to put that together with the limit switches (scroll down to the last schematic). You would have your LEDs light up by connecting them to the normally open side of the limit switches.

Okay... that's perfect!  It's settled... no arduino. 

For a first post to the forums, you guys are great!  Thanks for the direction and information.

Of course, this year I also want to build a race computer with GPS, multiple video streams, and engine data overlays... so who knows what will happen with that.