Author Topic: Interesting (Read 1936 times)

Bill Gruby · « **on:** March 26, 2007, 11:24:20 AM »

Hi All

You may have seen this already but here it is anyway. It interestd me enough to watch this "Forum a little closer than I have been.

"Billy G"

linheart smith · « **Reply #1 on:** March 26, 2007, 03:28:48 PM »

Bill,

That was the most amazing stunt pattern I have ever seen. We need to know more about this model.
Looked like very short lines. The verticle climbs were very slow. All corners nice and square.

??

Linheart

Mike Palko · « **Reply #2 on:** March 26, 2007, 04:04:48 PM »

That is a very cool video, thanks for sharing. It looks like it flies very yawed out, so I assume there is a LOT of motor offset (allowing it to stay out on the lines). Now if only it would hold the slow speed uphill and downhill!!!

Bill Smith · « **Reply #3 on:** March 26, 2007, 08:04:11 PM »

I WANT ONE. NOW

phil c · « **Reply #4 on:** March 26, 2007, 08:34:01 PM »

Except for the bottoms being mostly at 1-2 ft, that was probably the best flight I've ever seen. Poor little plane wouldn't have any room if the bottoms were head high though.

Rudy Taube · « **Reply #5 on:** March 26, 2007, 10:27:23 PM »

Thanks Bill,

That is a fantastic flight! I don't fly that good in my dreams!

I can see many more CL contests being held next year, back east, from NOV to MAR!!!

I have seen flights like this with our 3D R/C foamies indoors. My guess is that this is a plate wing foamy with a lot of offset like Mike said. Our R/C foam (Depron?) flat wing planes don't really fly, it is much more like "Force Vectoring" with the EL just pointing the motor in the direction you want to go to get the "track" you want to follow in the sky, (gym? ;-).

They are amazing machines. One of mine is about the size of a Jr. Flight Streak, weighs 15 oz (heavy, some this size are 11 oz.), it is painted, with full LG, steerable tailwheel, 4 CH radio, and a BIG Hacker motor. It goes straight up, out of my hand, doing rolls until it is out of sight. When I get a chance, I want to put lines in one of my foamies to try it. After seeing this video, I am getting more motivated to do so. :-) ..... Thanks again Bill.

Igor Burger · « **Reply #6 on:** March 28, 2007, 01:52:22 AM »

Thanx for posting Bill, sorry I did not answer earlier, I do not come so often.

for others:

yes, it is my model posten on http://www.clstunt.com/htdocs/dc/dcboard.php?az=show_topic&forum=103&topic_id=260048&mesg_id=260048&page=

Model is light flat depron tye indoor stunter. The weight is 160g (5,7oz) lap speed 4.9s motor python 60 (czech production 1400rpm/v 150mohm internal resistance 1.25oz heavy) ESC is Jeti Spin 11A with custom software with governor and brake, battery 2x 700mAh or 3x 360mAh (must be fresh if 360mAh and flight time only 3 minutes) and GWS 10x4,7 prop, lines are "up to top" 5m long green spiderwire fishing lines - they equal to steel cables of equivalent thickness so thinnest are OK

I also tested another czech motor, PJS 300 with MGM 710 ESC (also with custom software with governor and brake) and 3x 360mAh and GWS 10x4,7 prop

more pictures from building are here:

http://www.rcmodely.sk/index.php?stranka=zobrazclanok.php?id=300

Igor Burger · « **Reply #7 on:** March 28, 2007, 02:06:12 AM »

MIke, yes it is slow uphil, the mass inertia is jus small and so it cannot flight like a big stunter, however the speed is stable soo after corner so also figures like vertical eight does not make any problems and speed on bottoms are also low enough to make it well controllable.

Reagrding offset, yes it is clear, if you calculate centrifugal force at such small speed, you will see that it is far from enough to keep lines tight. Large model will fall down from skies at such speed. So the only solution was to simulate knife flight so the fuselage offset is made to be (by proper LO position and rudder offset) at ~20 degrees. I wrote several times on Stuka that small model cannot fly tangent to circle and such size takes it to extreme. This is also answer if model with such extreme offset can be trimmed to make corners clean, answer is yes it can. The only problem with roll happens at low speed when torque os the motor makes unwanted roll, solution for that problme will come next winter I hope

so to make the storry short, motor hase 0 side offset and approximately 15 degrees down offset.

Igor Burger · « **Reply #8 on:** March 28, 2007, 02:17:37 AM »

>>>bottoms being mostly at 1-2 ft<<<

yes phil, it is very low, but it gives much more space for figures

... if you compare lines length and corner radius, you will know what I mean

but seriously, yes it was very often foot or two, but beleive me, it is NO PROBLEM, such a model is on short lines much better controllable that 60ft far ... only r/c flyers did not understand what I do

Bill Gruby · « **Reply #9 on:** March 28, 2007, 07:19:58 AM »

Igor;

Thanks a bunch for stopping buy to give these guys the info about your success. I was happy to post the video here, it has made a believer out of me. Do you have plans available for this airplane? We have the Armory here available to us here and it has a 55' ceiling. Sure looks like fun to me. Thanks again for comming and don't be a stranger.

"Billy G"

Igor Burger · « **Reply #10 on:** March 28, 2007, 08:10:36 AM »

This kind of models not need any special plans, most you can see on this picture below. It is orriginal size of picturen on that upper link, if anyone wants them, I can sned them - they are 800KB each

However I have corel drawing for basic shapes, not any real plan, I can send it also.

Bill Smith · « **Reply #11 on:** March 31, 2007, 06:51:45 PM »

if you could send it to me I would like it very much

Igor Burger · « **Reply #12 on:** April 01, 2007, 05:54:31 AM »

30MB is on way

I also attached that cdr file, and I exported also gif files, may be it will be woth of past it also here:

Dean Pappas · « **Reply #13 on:** April 04, 2007, 10:00:52 AM »

Quote from: Igor Burger on March 28, 2007, 02:06:12 AM

... So the only solution was to simulate knife flight so the fuselage offset is made to be (by proper LO position and rudder offset) at ~20 degrees. I wrote several times on Stuka that small model cannot fly tangent to circle and such size takes it to extreme. This is also answer if model with such extreme offset can be trimmed to make corners clean, answer is yes it can.

so to make the storry short, motor hase 0 side offset and approximately 15 degrees down offset.

Hi Igor,
Let me see if i understand this correctly. Is the fuselage flying pointed outward from tangent? (of course it is but that's not the real question)
Is the wing flying with the span-line pointed directly at the handle?
This would mean assembling the wing and fuselage at an angle, with the stabilizer parallel to the wing and offset so that a line through the wing and stab centerlines is tangent to the circle.
I have contemplated doing this many times, but never built the plane.

This may have to move to the design forum, soon.
Thanks in advance,
Dean P.

Igor Burger · « **Reply #14 on:** April 04, 2007, 12:52:09 PM »

The model itself is "usual", so the wing span is perpendicular to the fuselage. But rudder and especially large front area points nose out. Result is nose pointed out ~20degrees from tangent - means also span is 20 degrees from pilot - CG line. I did not do adjustable leodouts, because it will be heavy, I rather used "adjustable" (knife and glue :-)) ) rudder.

That angle also moves elevator little bit to inner side of fuselage (elevator is symmetric, but fuselage in circle is 20 deg out) and its lift simulates larger outboard flap on flapped model. It allows little more tip weight giving better line tension in round figures (tip weight is trimmed to make clean corners so round figures are little bit "tip weight heavy"). I had problems in vertical eight on previouse model, now it is far better.

I do not see too much problems with that setup, actualy most problematic is propeller reaction moment when model slows down to the extent that the wing does not stabilize it anymore. In that point model rolls iward (shows top of wing). So result is that the model must fly shorter lap times than its ability allows (it can fly slower) but in that case reaction moment cannot be ballanced.

Dean Pappas · « **Reply #15 on:** April 04, 2007, 01:49:40 PM »

Hi Igor,
Now you need the contra-rotator!

all the best,
Dean P.

Dean Pappas · « **Reply #16 on:** April 04, 2007, 02:18:28 PM »

Hi Gang,
Here's the website for the outfit that make the contra-rotator, but they have not introduced it yet.
It is sized for F3A Pattern (2500W) but the idea is out there!
Dean

http://www.f3a-e-factor.de/deu/html/antrieb_index.html

Author Topic: Interesting (Read 1936 times)

Bill Gruby

Interesting

linheart smith

Re: Interesting

Mike Palko

Re: Interesting

Bill Smith

Re: Interesting

phil c

Re: Interesting

Rudy Taube

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Igor Burger

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Igor Burger

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Igor Burger

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Bill Gruby

Re: Interesting

Igor Burger

Re: Interesting

Bill Smith

Re: Interesting

Igor Burger

Re: Interesting

Dean Pappas

Re: Interesting

Igor Burger

Re: Interesting

Dean Pappas

Re: Interesting

Dean Pappas

Re: Interesting