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Apr 27, 2007, 09:09 AM
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Rowan's Runabout


I wasn't sure where to post this, here or over in Sport Planes. However, this model strikes me as a bit small for Sport, definitely more Parkflyer size and power, so here it is.

Anyway, whatever the reason it's here, the model in question is a little parasol design I drew up some time ago. Not too surprisingly, it's called Rowan's Runabout - this particular Rowan being the son of a friend. The original idea was that dad would build it for son to fly, but that never quite materialised, so it fell to me to build the model myself. It got a little revised in the meantime, and I built it using laser cut parts from Charlie at Manzanolaser.

So, the theory is that it is to be a 38" span, parasol model with a scale-like appearance. Although the revised plan actually shows a brushless motor and aileron option, it also shows a mount for a direct drive 400 and no ailerons. Since that's the way I like to fly, that is the version I have built.
Yes, all the basic construction is completed, but it will be staying that way until I get another couple of models to the same stage. Then I can clear all the tools off the bench and have a mass finishing session.

There's nothing complicated about the build, it's all very straightforward stuff. Anyone in the least familiar with my designs will know what to expect. So, from here on in, I'll let the photos, with captions, tell the story.
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May 24, 2007, 01:15 PM
Light and floaty does it
Work in Progress's Avatar
Peter, that's pretty. The pointy nose brings on impure thoughts of your mock-scale era. I reckon with this basic parts set you reduce the span a little and do a nice little staggered biplane, filddle the tail surfaces and the tip shapes a bit, laminate up a glass blade undercarriage and it could be half way to a Fairey Fantome.

Well... sorta, kinda, anyway
May 25, 2007, 03:53 AM
brennanj2
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Hi Peter,

Thought I would check it out this thread, I had missed it before.

You could say there was a slight family resemblance.

Did it come from Tasmania?

Any further progress?

John
May 26, 2007, 06:53 AM
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WIP,
Fear not, the biplane version is in mind. Not 100% sure how it will end up looking, but I'm thinking about it. I hadn't considered the Fantome but I am now. A very pretty aeroplane.

John,
It still sits as you see it in the photos. However, I've decided to get the covering done sooner, rather than later.
I'll have to assume the Tasmania thing is an Australian 'in' joke. It's way over my head, but that doesn't take much doing.

Pete
May 26, 2007, 07:36 PM
brennanj2
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Sorry Peter,

I actually had second thoughts after I posted it but thought it sufficiently obscure to let it ride. It refers to the suposed genetic diversity. I am sure you get the drift.

Peter, may I make a sugestion? Would a slight back sweep of the wings , like a FW 56 , add to the dynamic stability and lift, in my opinion it would add to the character? An adjusted centre section would still allow the standard wings to be added. If the sweep back was slight the wing ribs may not even need to be adjusted.

Just a thought

John
May 27, 2007, 03:00 AM
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John,
Yes, I thought it might be something along those lines.

I'm always open to printable suggestions mate. I think a swept wing might require a full re-draw because the sweep would effectively increase the length of the nose - already fairly long. However, the idea is duly noted and stored away for future reference.

WIP,
Whilst looking for Fantome reference, I spotted one that it resembles even more closely, or would do given an extra wing - the Fairey IIM Firefly. Now, if I can just find a three view.

Right, I'm off to do some covering.

Pete
May 28, 2007, 05:07 PM
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Okay, after a pleasantly relaxed weekend of work most of the covering is completed. The access hatch still needs to be made and covered and wing struts made and painted. Also to be painted are things like u/c, cockpit, c/s struts and spinner. I want them sorted out before I assemble the model and start to get the gear in. At present, the model is only dry assembled.
As you see it here, the model is covered using Solarfilm - white that I discovered lurking in the shed and yellow left over from Ryan's Daughter. The black pinstriping is actually strips of Fablon (Con-tact) shelf covering type material. It seems to have gone on reasonably well, the curves being induced by using the covering iron set for low heat - just enough heat to persuade the vinyl to bend without puckering. I've used this method on ic powered models in the past and seem to remember it being reasonably successful - as long as it was fuel-proofed. Obviously, that isn't something I need worry about on this model.
I'm happy with the way the model is coming along and the wife has declared Rowan's Runabout 'very pretty'. Not sure if that's a good thing or not.

Pete
May 28, 2007, 05:15 PM
Light and floaty does it
Work in Progress's Avatar
Very pretty indeed, Peter, she's right!
I agree with you on the Fairey Firefly II, it looks eminently makeable in an enjoyably cartoon-scale way from this.

The "Fairly Firefox", perhaps???
Jun 01, 2007, 04:49 PM
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Work on Rowan's Runabout is progressing, albeit at a slower rate than I would have liked. However, basic assembly is now completed and the model has gained a few decals. Nothing special, just home printed waterslide registration and name.
It's also received a bit of paintint work and a little 'scale' detail - a cockpit coaming.
For those interested, the coaming is part of a lightweight rubber moulding I obtain from a vintage car specialist supplier. It comes as a sort of O shape on an inverted T. Pulling off the T part leaved a rather nice C shaped piece that fits over cockpit edges quite nicely. Helpfully, it always seems to tear in the same way, leaving neat edges to the C. Just grab the two parts and pull - instant cockpit coaming.
Hopefully, the week-end will see the model completed and ready to test fly.
A pair of 5 gram servos and pushrods will take care of rudder/elevator control and a 2s LiPo will, hopefully, supply the urge to the direct drive 400 motor.

Pete
Jun 02, 2007, 03:52 PM
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With the exception of arranging battery installation, Rowan's Runabout is complete. Including the battery, a 2s 1800 mAh pack, all up weight is 16.25 oz.

Pete
Jun 02, 2007, 06:46 PM
cool!!!

Robert
Jun 03, 2007, 06:35 AM
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Well, I thought the model was finished, right up until I went to set up the radio gear. As soon as I plugged in the battery, the motor burst into life at full throttle and the only way to shut it down was to unplug it again - a task fraught with peril.
With the motor removed, after first checking I had it plugged into the throttle channel, the signal wire had come off the ESC. Soldered back into place, it made absolutely no difference whatsoever. The motor still fired up at full power and this time managed to clip me with the prop - I'm awfully glad it's a 400, not a big BL motor.
It's all a bit strange really, I've no idea why this, and another, ESC should give this response. There isn't too much you can do to protect against this sort of situation - apart fropm remembering to remove the prop before testing. Anyway, one more change of ESC, this time to an unused Kontronik Sun 1000, and things were working as they should be. As I say, I'm totally puzzled about what's happened to the other two ESCs but they're now in the rubbish bin.
So, all that remains is to fully charge the battery and transmitter and wait for opportunity to coinside with weather conditions fior test flights. In the meantime, here's a few shots I took outside. It's annoying really because today is perfect flying weather and ideal flying shot weather too - bright and sunny.

Pete
Jun 09, 2007, 05:55 AM
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Just to finish off this thread, here's the flight report for Rowan's Runabout - along with some flying shots.

First off, let me just say that it was well worth waiting for a bright, sunny and calm (ish) day. After a solid week of wind or rain, or wind AND rain, today looked perfect. Not too much wind and actually some sunshine. So, at about 0815, the wife (head photographer) and I set off for the flying site.

I'd like to say that everything went perfectly, but that wasn't quite the case. There definitely appears to be something wrong with the motor or ESC, or possibly both. A direct drive 400, 2s LiPo and 6x4 prop should provide ample power for a 16.5 oz. model - but not in this instance. Admittedly, the grass was a bit long for those little wheels, but the model should have at least tried to take off. Instead, it just sat there with the prop going round.
Okay then, try a hand launch - bad idea. From hand launch, the model staggered away, tuned gently left and cartwheeled most majestically as I tried to land it. So, first thing proven, this is a TOUGH little model - absolutely no damage at all.
Having thought to take a second battery pack, that was put in the model and the motor run up. This time there was slightly more power, but still not as much as I was sure there should be. Still, we were there, the model was ready and the weather was about as good as you could wish for. Time for another hand launch. This time, with a little coaxing, the model climbed away nicely. Very slowly climbing, but climbing nonetheless. After a pleasant flight, with lots of low passes for the camera, power started to drop away and the model fell foul of the rabbit fence around our strip.It looked a lot worse than it actually was, damage being restricted to one wing strut popping out of place. Slip it back in, replace the battery and try again.
Since the problem obviously wasn't with the batteries, I tried the initial pack again. Better this time, the model was actually flying on this pack. Then it happened, suddenly, the motor note changed, model speed increased and it actually began to climb quite fast. Add a little down trim, throttle back (yes, REDUCE power) and we're cooking. This time, the model was really able to show what it's made of.
Okay, so the motor's a little noisy, sounding a bit like a little deisel, but the model is flying well so who cares. 400 motors are cheap enough and this one was already suspect. Time for some fun and hang the expense. I was beginning to enjoy myself.

So, that's how the flying session went, how does the model fly? Given enough power, very well indeed. I like the model, it is stable enough to be pleasant to fly - even though mine was a little marginal on balance. I thought it might be, but was prepared to risk that. The only obvious effect was a tendency to climb and stall occassionally. However, even that was no bad thing because it demonstrated that as soon as the model stalls, the nose drops straight ahead and she carries on flying as before. Absolutely no inclination to drop a wing in the stall.
Although of parasol configuration, and nicely stable, that doesn't mean the model is boring to fly. Even on R/E/T control, the model does a very nice line in steeply banked, sweeping turns. A little dab of opposite rudder soon has her flying straight and level again. Even on the rubbish powertrain in my model she will loop quite easily and I have no doubt that stall tuns and barrel rolls will be par for the course.
After three flights with the model, I'm very happy with her. Within moments of getting airborne I felt confident enough to try low passes and banking turns. A little right rudder and some down elevator trim was needed, but that's only to be expected of a completely new model. She's easy to fly, can be mildly thrown around and is extremely pretty as she shows off the sunburst scheme in those steeply banked turns.
As for the motor/ESC, at least one of them is fried. When I removed the hatch to take out the battery, my nostrils were assailed by a distinct smell of cooked electrics. What's more, you could actually feel the heat penetrating the balsa nose. Surprisingly enough, the battery was warm, but far from worryingly so. In fact, I think the nose was probably as warm as the battery.

Pete
Jun 09, 2007, 07:59 AM
Neophyte hacker
portablevcb's Avatar
Peter,

Very pretty. Now I know where you are getting the fuse for the other design. You know me though, I'd just have to hack in ailerons

ESC's. Might want to dig out those from the trash bin and see if they are reversed in signal. In the 'old days' I ran into a couple that were reversed. They did not go to full throttle though, just didn't seem to work until I reversed the 'servo' setting. Then they'd arm and run properly.

charlie
Jan 27, 2008, 05:25 PM

Giving me the runabout!!


My first ever plane that I have built from scratch
So here is my attempt at building a Rowans Runabout!
I have a brushless motor and ESC from a JP Pretty which I think will be ok,Im not sure of the power rating but it works just fine with the Pretty.
Got to go hunting on Ebay for a Li-Po and a prop,other than that I have all the electrics including some tiny servos.
I was going to use my Hitec focus4 Tx as the model only requires 3 channels but going to use my DX7 insted..get to add another plane to the memory!


Still more to get on with...will update soon....lots of luv,Balsa lover


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