baprc wrote:Hey guys, what exactly counts as a "pre-covered" surface? Also, since I am new at this event and our school is bad at it, do you guys have any advice? I was wondering if this could be legal: http://darehobby.com/airplanes/airplane-zingwings.htm .
Since the glider is completely pre assembled, I would not consider it a kit. Also the rubber band used to upen the wings is not one of the permitted materials. I do understand the need for a simple plan to get started.
I will try to locate one of the beginner plans and instructions and get it posted somewhere so the new people have a starting point.
My beginner plan is now posted in the test exchange with the assembly instructions.
When you print the plan make sure it is the correct size by checking the reference line below the wing. It should be 50mm long. If you have questions about the plan or instructions, please let me know.
Anybody here considering carbon fiber for their gliders this year? We had an all-balsa glider last year that performed well, but considering the weight change in the rules, we're thinking of using a carbon fiber fuse. We think that it would be significantly more sturdy, which could eliminate a lot of the repeated testing we had to do last year because of shattered fuses. Any thoughts? What design aspects are others changing to get their gliders to 3.0 grams?
I am aware of at least one non-SciOly indoor glider design that uses a carbon fiber fuselage and tail boom. There are several drawbacks to this design option. 1) cost; 2) requires different adhesive for proper bonding; 3) potentially uncomfortable carbon fiber splinters; and 4) awkward joining of flat wing and stab surfaces to a round carbon fiber fuselage and a round carbon fiber tail boom, respectively.
On the good side, a carbon fiber fuselage and tail boom arrangement would be very light, rigid and strong if the proper diameter(s) were selected. Variations in humidity would be less likely to change trim if the glider has a carbon fiber tail boom. While breakage of a carbon fiber fuselage and tail boom as a result of a crash would be unlikely, there would still remain a significant possibility of fracturing of the wings and/or the wing/fuselage/pylon joints as a result of a crash.
On balance, partly due to the small scale of the 2014 elastic launched glider, and the 3.0 gram minimum weight, probably a lot of time and trouble would be saved by simply using a tapered stick of harder balsa, e.g. 8-10 pound density, for the fuselage and tail boom.
Last edited by calgoddard on Mon Nov 11, 2013 6:57 am, edited 5 times in total.
As an alternative to carbon fiber, it wouldn't take much to drastically reduce the shock from the nose hitting the floor after a bad launch. Just add a little foam rubber or soft rubber padding to the nose (foam is allowed by the rules, ). You typically have to ballast the nose anyway plus meeting the cap rule.
arod129 wrote:How do you make the glider go in horizontal circles instead of loops? Thank you
A couple of quick things to check. Is your horizontal stabilizer straight and flat to the fuselage? If you have any angle it could cause your glider to 'pull up'. Also check your main wing to see if it too has an angle (nose up), that too should be just about equally flat to the fuselage. Maybe your CG is too far aft, try to make sure CG is about just behind the center line span of your wing. It's different for all gliders so play around by putting a little clay on the nose. A little clay makes a big difference. Hand launch in your living room and adjust until you get a flat glide. As far as circles, glue your vertical stabilizer on the fuselage with a slight angle to the direction you want to go, leave a little bit unglued at the trailing edge for anymore adjustment. Hope this helps some...
Just checking:
Moving the wings back on the fuselage would move the center of gravity forward right? So you'd need less ballast?
Or did I get it opposite again?
Yes, you have this correct. Moving the main wing rearward on the fuselage will have the effect of shifting the CG forward, thus reducing the amount of ballast otherwise needed on the nose to achieve a nice glide. But be careful. If the main wing and the stabilizer are too close together instability can result. The optimum distance between the main wing and the stabilizer depends on the design of the model. Check some of the successful designs, such as Ziegler's Freedom Flight Models design, for a reasonable distance.
I wanted to get your guys' opinion on how I could fix one of my gliders that i have recently built. The glider that I built is similar to the WIF7 design, but less complex, mostly the same shape and dimensions, but scaled down to fit the scioly requirements. I have carbon rods on the fuse, but no carbon tow on the wings. It utilizes a "flapper" design with durobatics foam. I am currently having a issue of getting it to transition properly. My situation is as follows:
When launched at a 30 degree upward angle it immediately turns itself so that the wings are perpendicular to the ground and does a fast arc into the ground with a very hard landing. I have trilled launching it rolled 90 degrees to the right, 90 degrees to the left and everywhere inbetween, but it does not want to stop this odd turning. It flies perfectly when hand launched to test the glide, but refuses to work when launched.
Any help with ideas of how to trim this glider to make it work would be much appreciated!
