Jackdaw

[Pchristy]

Its taken longer than I anticipated - life keeps getting in the way! But its nearly there!





To do: Paint trim on wings and tail, cover control surfaces, build transmitter.....!

It could be ready to test fly next week-end, initially using my Royal Classic Tx. Ultimately it will be controlled by a Grundig Variophon 10, donated by Mike K and "Giga-ised" using one of Phil's "Reeduino" boards and a FrSky module. The old Tx is now stripped ("built like a battleship" barely begins to describe it!) and awaiting its new innards.

Onwards and upwards......!



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Pete

[Igull]

Looks great Pete, I always fancied this as a kid - absolutely no chance of ever being able to afford it of course (could only letch at the Frog catalogue !
Look forward to seeing a flying video
Cheers
Neil

[Pchristy]

Cheers, Neil! Your laser cut ribs made the wings and tail much easier to construct, I have to say!

I'm just painting in the cabin windows (waiting for the first coat to dry as I type this), then its on to the wings and tail. With a bit of luck it could be test flown next week-end.....

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Pete

[Pchristy]

Its finished! Final checks tomorrow, and hopefully, test fly on Saturday....







Ran the engine up briefly this afternoon to make sure the settings were in the ball park - almost spot on! Its a new ASP 30 4-stroke, so it will need a bit of running in.

I was intending to test fly it with my Royal Classic Tx, which has been giga-ised. Sadly, the throttle is working in reverse, and isn't changeable on Phil's encoder, so as a stop gap I've fitted a servo reverser.

Now I could have built one from scrap, but to save time I bought a Turnigy one. Cheap as chips. And now I know why! As soon as you put any load on any of the other servos, the throttle jitters like mad! Grrr!

Now Futaba servos work in the opposite sense to JR and Hitec - but of course, I don't have any Futaba servos lying around. Actually, that's not quite true - I do have a very scruffy one I've inherited, but its slightly bigger than the Hitec that's in there! Grrr! Again!

Might have to use the Taranis for the test flight, if I can't find another solution.

Forecast is for rain all day tomorrow (again!), so I have time to work out a solution.......

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Pete

[Martin]

Looks great! Hope for good weather for the test flight.

You can reverse a servo by swapping the two motor wires and the two outer feedback pot wires.

Depending on the transmitter you can sometimes reverse a channel at the transmitter by swapping the two outer pot wires on the channel you wish to reverse. If there's a separate pot for the trim it sometimes gets tricky.

[stuart mackay]

Now that looks so pretty! Great Job, Pete!

[Pchristy]

Hi Martin,
Yes, I know about swapping servo wires. The problem is that modern servos aren't designed to be that accessible! The motor is soldered straight to the board and then glued in! To remove it risks breaking the case.

Phil designed his encoder to be "idiot proof" for electric flyers - a fairly sensible setup, unless you are flying IC and have the wrong sense servo! The way the logic works is that the encoder won't fire up unless it detects a low throttle condition. Reversing the pot would mean that it would only fire up at full throttle - perhaps not the wisest move!

The simplest solution is to reverse the servo - not practical on the ones fitted - or find a Futaba the same size, which I don't have again.

I guess it will have to be the Taranis on Saturday, unless I find a better solution tomorrow!

Thanks for the comments, guys! I'm quite pleased with the way its turned out. Just hope it flies as good as it looks....!

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Pete

[Martin]

Ah okay. I thought you'd know all the standard tricks!

Is there enough room to fit the servo upside-down with some packing pieces? It makes attaching the linkage a pain, but if there's room it does sometimes work.

[RON]

What about a pic based reverser.
Just plug the servo into it.

Ron

[Mike_K]

Hi Pete

The model looks a treat, I remember them as a kid, but don't think I've seen one since, a good choice.

It should be easy enough to change Phil's code in the Arduino transmitter encoder to swap the servo direction, if you don't mind reprogramming it. If you need a hand with the code I can help or I'm certain Phil would oblige.

I'm surprised you're having problems with the Turnigy servo reverser, I've used 3 or 4 without a problem. I've had a look at their circuit and there isn't any decoupling caps, so you could try fitting one. If that doesn't work I've got a couple of great servo reversers from the 70's that I could let you have. They're designed by a chap called Christy, I don't know if you know him

I'm not doing so well with my model for the Variophon, I built two left hand fuselage sides earlier this week. I've also been spending far too much time messing about with a Lil Toad delta with a Rand LR3, I can see me running out of time and having to fly my Variophon in my old Tyro Major.

Cheers

Mike