20 sized Stunter

[Chris Gilbert IRL-1638]

Hi folks,

Here's a few shots of my latest nemesis under construction.

It's ~300 sq in of area, and a OS Max 20 is destined to haul it around. As seen it weighs ~ 16 oz.

I'm expecting to fly it on 52 foot 0.012 lines.

I'm not sure who the original designer was as I bought my first version of this model from a friend and made up drawings from the subsequent wreckage (sigh).

Out of curiousity I built it up as per Mo Best - warren girder structure sheeted by 1/16 balsa to the rear.
I recycled the stab and elevator from the wreckage, but if I was to build another one I think I'd make these geodesic. Looks like it should balance without too much lead at either end.

Not sure how the UC will work out either, but I'll try most things once.....

[Bill Little]

The fuselage and wing look like the Magician 15.   Just a change to the tail feathers wing tips, and moments.  It should be a fun little plane!

Bill <><

[Andrew Raney]

It looks like a Sukhoi 31 to me.
Andrew

[Brett Buck]

Hi folks,

Here's a few shots of my latest nemesis under construction.

It's ~300 sq in of area, and a OS Max 20 is destined to haul it around. As seen it weighs ~ 16 oz.

I'm expecting to fly it on 52 foot 0.012 lines.

<<snips>>
Not sure how the UC will work out either, but I'll try most things once.....

       I surely hope you mean a baffle-piston 20 and not an FP. Assuming that, it's in the right ballpark as far as the size goes -maybe a little on the small side but probably OK,  The first "big" engine I ever bought was an OS-20s, and I used it in several airplanes around that size or a little bigger.   I think you will find it pretty quick on those short lines, but that's something that can be adjusted later.

     The landing gear looks pretty "tippy" to me - really high but narrow. It appears you could probably fix that by bending it flatter and still have enough ground clearance for a 9" prop.

     Brett

[Chris Gilbert IRL-1638]

Hi Folks,

The model is an interpretation of the Sukhoi 26/29/31. It could be based on the magician, but I couldn't swear that it is. The structure is all mine, I took the section, moments and planform from the plastic bag I brought the bits home in, and filled in the blanks myself. The original was a C box section, with cap strips, but the wing structure shown was intended to save a bit of weight.

The powerplant is a fairly old OS Max 20 (bought second hand in the 80s and only run for the first time earlier this year). I need a degree of power as flying conditions here are normally "blustery" and based on my experience flying here I'd be unwilling to put an (older) smaller engine in a model this size.

I was debating putting an OS 10 LA up front, as it hauls a similar sized flapless airplane around with no problems (UK Peacemaker), but I reckon the Sukhoi needs some extra grunt because of the flaps (yup, I can and do stall them sometimes). I'd guess any of the current crop of 15s would make this model "exciting" on 52 ft lines. A PAW 15 or 19 would make an interesting alternative power plant too.

Of course, if I want excitement I can drop a 25 LA in and put it on 60 ft lines, but maybe not.

[Leester]

Did you get that table cloth from Walter Umland???

[Jim Thomerson]

I see you have D-tubed the trailing out a ways.  Wouldn't hurt to put vertical webs between the spars.  I'd run them all the way out in the outside wing as I sometimes pick airplanes up by the outside wingtip.