New Scale Indoor Bipe

[CF Av8or]

Here are some build shots of my latest creation for indoor flying.

It's a 1/20th scale model of a WWI Sopwith Pup with a 16" wingspan, which I'm planning to maiden tomorrow night. Construction is primarily 3 mil depron and take-out container foam, with a few wood bits and pieces.

It came in at 2.6 oz flying weight, which is higher than I wanted. Unfortunately, I haven't made the conversion to 2.4 Gig, so the ultra-micro electronics that are available are not usable by me as yet (need to get me a Spectrum Tx...). As a result I had to go with the smallest gear I have on hand which is still too big for this size of model. It'll still fly alright in a small gym (I hope), but I don't think it will be the ultra-slow flyer I was planning on.

[CF Av8or]

Some more pics...

[CF Av8or]

And one more. Done, less the markings...

[retiredVTT]

A real beauty Vic...yup if your gonna build them small and light you gotta bite the bullet and get the tiny electronics...some nice two and four gram receivers out there..etc, etc.

I'll try to get the maiden on video..

Bill

[lawndart]

That looks fabulous Vic.

Like your radio, mine has no compatible micro Rx's available either. I have to shoehorn a standard 6-ch receiver into my indoor models. On my Micro Eagle bipe I decided to do everything I could think of to reduce weight. I actually had some meaningful results taking the case off the Rx, ditching the satellite receiver, cutting all the servo pins off and soldering the servo wires directly to the circuitboard (thereby also avoiding the weight of the servo plugs). I cut down all wires to the minimum length possible and replaced the plastic servo bottoms with tape.

I really don't know if it was all worth the hassle. Soldering inside a foam model poses its challenges. Just de-casing a standard receiver makes a pretty big difference though -- mine weighs only slightly more than a regular micro Rx.

Can't wait (weight?) to see the Pup in the air!

[CF Av8or]

Thanks, guys. Here's a shot with the wing roundels painted on and ready to take to the sky (ceiling?) tonight!

[retiredVTT]

Video of the maiden flight here....

http://vimeo.com/32594744


Bill

[lawndart]

Bill, thanks for posting the vid; Vic, that is such a gorgeous model I'd be afraid to fly it! Looked like you might have a cg issue. What was your assessment? I find it impossible to maiden an indoor model indoors. I need a calm morning outside with room enough to do a real shakedown. Otherwise the walls just close in on me!

[CF Av8or]

Yes, I agree with both of your assessments.

I believe that the c of g was too far aft, which resulted in the pitch-up tendency and the extreme sensitivity of the controls. I've added some weight to the nose.

Secondly, I totally agree about test-flying a model indoors. Definitely not the best place to try out a new design. I'm now waiting for a calm day to do my next flight outdoors where there's a little more real estate! I'll let you know how that goes.

Cheers,
Vic

[CF Av8or]

Success!!!

A too far aft C of G was, as I suspected, my problem all along. After doing a recalculation of the correct position, I could see that I was almost one cm too far aft. After adding 4 gms of lead to the front of the cowling, it was finally where it should have been all along. Then it was a matter of waiting for calm conditions, as I was not about to try another test-flight indoors in such a small venue as Prospect.

This finally came yesterday morning, so it was off to PLF for a dawn flight. With a hand-launch from Mary, the Pup was off and winging it's way skyward, under total control this time! It flew beautifully with plenty of stability, but still able to crank out some tight maneuvering.

I flew out another two batteries just before sunset at Stoney beach at low tide when the wind died off again. The sand was dead smooth and perfect for touch and goes, which the Pup performed nicely. It handled some fun rudder/elevator aerobatics as well.

After a frustrating first attempt at Prospect the other week, it was rewarding to see the Pup performing as I had anticipated. It's not nearly as slow a flyer as I would like, but that is due to the larger electronics I was forced to use and the requirement for the nose-weight (darned, short-nosed, WWI planes!) that increased the AUW.

So, perhaps a Spectrum radio is in my future, so I can use some of the ultra-micro gear available for it...???

Cheers,
Vic