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Jef Ott

electric free flight design

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Jef Ott

Pics of the Pixie decs. 

Happy New Year!

 

IMG_20151231_191826.jpg

IMG_20151231_191700.jpg

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Jef Ott

One last Pic of the Pixie decs, sorry it is so out of focus, but hopefully you can get an idea of the scale of the transfers. 

 

 

IMG_20151231_191732.jpg

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PeterT

Jef it looks pretty good to me, and I raise my glass to you in an early New year toast (and then go back to building a vintage coupe tailplane:rolleyes:)

Cheers

Peter

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Jef Ott

Been hunting around for materials to make a suitable spinner in my travels for a couple of weeks. Found an old rocket nose cone (made by moulding Guru Mike Francies)... 

 

Pixie Complete 9.jpg

Pixie Complete 10.jpg

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EssexBOF

I remember those old KK transfers well as they used to split when  they opened out after soaking in water. Also the teribly cut wood for for stringers,spars etc, as it looked as though they never sharpened the saw blades:rolleyes:

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Jef Ott
2 hours ago, EssexBOF said:

I remember those old KK transfers well as they used to split when  they opened out after soaking in water. Also the teribly cut wood for for stringers,spars etc, as it looked as though they never sharpened the saw blades:rolleyes:

The transfers made with Craftovator waterslide decal paper, and painted with acrylic varnish, are easy to work with if you want me to do you some any time Brian.

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Jef Ott

The Porky Pixie has flown under it's own (rather wet) steam!

Did it cavort about like an enraged aging bullock in a poppy field in the springtime? No.

Did it screw in hard left under it's torque, despite the control surfaces all asking for 'a bit of right turn, please'? No.

Did it barely maintain height under power? Yes.

Did increasing the speed control make any difference? No

Was it bloomin freezin' cold and were the batteries well past their sell by date? Yes.

Lesson learnt! When setting up for the required ounce of thrust, do it at the same temperature you are going to be flying the thing at, not in a centrally heated house with the boiler going full blast in an attempt to get 'Er Indoors feet warmer than 273 Kelvin.

The tailplane needed a smidgeon of trim to keep the nose up, but once that was in place, the flight was shockingly sedate. Despite weighing more than Concorde, the Pixie is a really slow, gentle, flyer.

Am I proud of it? Bloody right I am!

Now? Looking forward to seeing what it goes like with a new battery pack strapped in the cockpit.

Jef
 

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Jef Ott
On 13/01/2016 at 17:44, Jef said:

Now? Looking forward to seeing what it goes like with a new battery pack strapped in the cockpit.

Wow :D

What a superb little flier the Pixie is, with the help of the Over The Top electric set up.

With the wick turned up quite high (probably about 50%) it almost did the first half of a loop, at about 10m it then stalled back to the right way up (how did it do that??), then corkscrewed up to a good height, before settling into a healthy turn, peaking at about 25m.

That was a bit too much excitement for me though, I prefer a steady climb, so I found the point on the controller that the model will just about climb, and enjoyed doing a lot of walking around the local park, in the absolutely still, but freezing cold, evening air. 

Magic!  

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PeterT

Great stuff Jef, I'm glad it turned out alright in the end. Like you, I've found that 'iffy' lipos and cold weather don't make for good flying (and frozen ground isn't forgiving) :rolleyes:

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Jef Ott

Dad and I went out with my sister as chief fetchermite, to the local park today. Surprisingly, the Competitor flies faster than the Pixie.

Nice one of Judi and Dad.jpg

Pixie and Competitor.jpg

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Jef Ott

Even with a head start, the Competitor was soon overtaking the Pixie (horizontally). 

Drag race.jpg

Drag race away.jpg

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Jef Ott

Through the marvellous Ebay site, I have acquired an original Keil Kraft Competitor kit, from the Wickford factory, minus the stripwood and rubber.

Will be photocopying the rib and former sheets and using better quality balsa. Now that I am driving an efficient diesel powered car, a round trip to Balsa Cabin costs me less than a gallon of juice and at less than a quid a litre, it felt like a cheap day out, but the current price of 20 sheets of balsa and 3 sheets of plywood soon made up for that!

Are there any hints and tips regarding building this superb looking model?

Will be starting afresh regarding the electric motor setup, and have to admit RCDT seems like a good idea.

Thanks in advance,

Jef

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PeterT

Jeff

I've always liked the looks of the Competitor, along with its little brother the Eaglet, but haven't you built a Competitor already (see last rely)? If anyone else is interested both plans are on Outerzone.

The only thing I'd suggest is that you steam the fuselage longerons to get them close to the final shape and take a bit of stress from the assembly - but I feel sure you'd do that anyway.

Happy building

Peter

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Jef Ott
1 hour ago, PeterT said:

 

I've always liked the looks of the Competitor, along with its little brother the Eaglet, but haven't you built a Competitor already (see last rely)?

Sorry for ambiguity. The yellow Competitor was built by and belongs to my Dad. 

 

1 hour ago, PeterT said:

The only thing I'd suggest is that you steam the fuselage longerons to get them close to the final shape and take a bit of stress from the assembly - but I feel sure you'd do that anyway.

So glad I asked the question!

Really am that naive... I would not have dreamt of steaming the longerons. Makes a lot of sense. Allows a harder grade of balsa to be used easily. Nice one Peter T! 

All such comments very gratefully received. Keep 'em coming!

Jef

 

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PeterT

Jef

I'm pleased to be of assistance. For too long, on small models I've wangled bent longerons into position and held the shape with glue, but realised that it's not the best way of doing it. It's not a lot different from putting saw cuts in triangular corner strips on sheet fuselages, but I've not built one of those for a long time. I hope the build goes well. What do you intend to cover it with? I'm sold on tissue over mylar which gives you strength and makes the airframe weatherproof.

Cheers

Peter

Edited by PeterT
typo
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PeterT

Jef

To give you some idea (although this fuselage isn't as swoopy as the Competitor), here's a photo of a vintage coupe fus. The design calls for 4mm fuselage longerons, and despite using light wood the force needed to get the correct shape was too much for my liking................but a few seconds over a steaming kettle (or soak for a bit in boiling water) relaxed the wood sufficiently to form it easily with no stress on the spacer joints.

Peter

Coupes 045.jpg

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Jef Ott

Hi Peter.

Thanks for the pic of the coupe fus, it looks very strong.

So, with the Competitor, would you aim to pre-form the longerons and assemble them dry, or just glue them in place while they are still pliable from steaming/soaking? 

There is a difference, although it would probably be negligible. Pre-formed/dry ones will be slightly less stressed than those glued while softened.

Does the wood need to be dry if using PVA, or would a deeper penetration of the adhesive into wetted wood make for an even stronger joint? 

Sorry for all the silly questions. 

Thanks very much,

Jef

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PeterT

Jef

Thanks - the fus might be good for reinforcement to avoid the problems aired in the 'Shed' topic:D

I've never really thought about  wet vs dry, but like you don't think there would be a noticeable difference. On the coupe fus I steamed them to shape and glued pretty much straight away, as they were virtually dry compared to those soaked in water. As for gluing, I'm conscious of the passing years (and so much still to do) so I normally use cyano rather than waiting for PVA or aliphatic to dry:rolleyes: I suspect that PVA would penetrate the fibres of wet wood better, just as pre-gluing with diluted balsa cement is often recommended (not when using PVA of course;))

Peter

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Jef Ott

Reading through the instructions (I know!) of a KK Ladybird, I note that there is another way of pre-shaping the longerons.

 

Ladybird curves.jpg

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PeterT

Jef

That's the way I normally do it for the hard balsa or basswood leading edges of hand & catapult launched gliders with solid balsa wings. It certainly works but reduces the cross section of the wood by compressing the grain. I'm not saying don't do it this way, just reporting the effect.

Peter

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