Materials/Kits

[DoctaDave]

http://georgesun.github.io/freeflight/# is also a great resource with many utilities and lots of various links.

http://freeflightsupplies.co.uk/ Also sells stripped rubber but at .005 in increments however he also sells a lot of various tools. I think his website is worth giving a look but he is also based in the UK which could increase shipping costs.

[bjt4888]

I have the greatest respect for Jeff Anderson and if students read all of his forum comments carefully, they will have an excellent framework for success with this event and for a fulfilling science experience. I do however have a slightly different perspective on use of kits like the one available from Freedom Flight. I am an experienced indoor flyer and an occasional competitor and have coached several high school science olympiad teams in elastic launch glider and Wright Stuff and other indoor rubber powered airplane events for the last eight years. As the time required to construct a high-quality Wright Stuff airplane is a pretty fair commitment for the students, and as I have found that a number of students involved in SO are also involved in other activities, limiting SO time to a certain extent, I like the idea of using the Freedom Flight kit in order to get construction done as efficiently as possible and allow more of the student's time for testing, data recording, modifications and learning a systems approach to problem solving.

The four high schools that I coached last year constructed eleven Freedom Flight kits in total. All flew over 3:15 in gyms with the usual 25 ft. 27 ft. ceilings. The team that put the most effort and time into the project, Holt High School, won the Michigan State SO Championship with a flight of 3:46 in a 21.5 ft scrubbable ceiling gym. They also won two of the larger invitationals in mid-Michigan with similar results. The modifications the students made to these kits are described (and pictured) in the 2015 SO Wright Stuff forum. These kits fly great!

I agree with Jeff that for the same money as a Freedom Flight kit package (which constructs two airplanes) you can build about five airplanes from scratch. However, unless you already own a stock of reasonable quality balsa wood, or have a local source to purchase balsa wood, it can be a little tricky to get the wood you need without buying a few sheets of each size by mail order. The rules for this year do not require especially good quality wood, but, in my opinion, it would be a good idea for the fuselage and tailboom to be a maximum of 8 lb/cu ft density range and the wing and stab spars to possibly be a little more sturdy (maybe 12 lb, or very stiff lighter wood). Buying a few sheets of each size will ensure that some of the wood will be in the correct density range. Remember too that even if a sheet of wood is in the 10 lb range, it might actually be made up of sections of 8 lb and 12 lb wood and you can cut from the various sections of the sheet to get the result that you want. These weight ranges (with reasonable grain and stiffness) should easily bring the airplane in underweight and most likely make it sturdy enough to handle the high speeds required by the ballast bonus.

Good luck and good science.

Brian Turnbull
AMA since 1972 (off and on)
NFFS also for a long time (off and on)

[jander14indoor]

I don't think we disagree much. Several of the available kits build fine airplanes. I just think an experienced builder/flyer deserves to learn how to build scratch to open up the opportunities to explore and to free them from the constraints of kitted products.

Plus, ulterior motive, if you only offer kits, how will you move the flyers onto Penny Planes, Mini-Sticks, EZBs, F1Ds, etc...

Other ulterior motive, wood selection and gluing skills developed for Wright Stuff is directly applicable to the Bridge/Tower/Boom events.

Jeff Anderson
Livonia, MI

[bjt4888]

Jeff,

I agree completely that learning wood selection is one of the important skills that Science Olympiad teaches. My students use the Slobodan Midic spreadsheet to calculate modulus of elasticity from buckling strength to learn about density and stiffness of their raw materials. This measurement, along with deflection testing matching of wing spars is very interesting for the students. It's a real eye-opener for the students to discover that some of the lower density wood can also be stiffer than the higher density wood. This leads to the discussion of optimal wood density and stiffness for each component.

Very good real-world test engineer stuff! One of my brothers is a test engineer in the auto industry and we have many interesting discussions about SO.

Thanks again for your support,

Brian Turnbull

[bjt4888]

Hi All,

Here are the first Freedom Flight Kits completed by my students. As usual, the kits include excellent wood with density and weight matched to the need for each part, excellent instructions and everything you need except glue and paint.

You will see from the pictures that my students modify the kits to a certain extent.

Brian T.
AMA since 1972 (off and on)

[bernard]

Looks like Volare products has some Ikara props that match this year's specs: http://volareproducts.com/BUY/index.php ... h=56_42_97

[bernard]

I've confirmed with Dave Zeigler the procedure for ordering this season's kits, while we wait for the site to be updated: purchase last season's kit from his website (http://www.freedomflightmodels.com/paypal.htm) and he will send this year's kit, since the prices haven't changed. For Wright Stuff, the new model is a complete redesign, and will look substantially different from last year's model, so here's a picture of what to expect:

[Less_Incidence]

Wow, that looks like some really interesting variation from last year's design. The minimal tip plates replaced with huge dihedral, and an offset stab, probably due to the torque rolling problem that many of us have been experiencing. Looks like the airfoil thickness has gone up, and that rudder design is... intriguing. I'm not sure I like the idea of that strange aspect ratio on the rudder, but I'll leave it at that.

[TSOlympian]

Wow the new kit looks really different! Is it just me or did they choose thicker/heavier wood in some places? (like on the leading/trailing spars)
How does it fly?

[bjt4888]

Less_Incidence and TSOlympian,

My four teams have built eight of these Freedom Flight kit airplanes so far and, just like last year, the kit contains quality wood and excellent instructions with pictures and diagrams. Everything (including three thicknesses of rubber and a small sanding block for the dihedral angle work) is included except glue and paint. I can attest that it flies great. The wing and stabilizer spar wood is exactly the same as last year. It just looks thicker relative to the small wing chord. The airfoil is thicker, which makes sense for a payload airplane. Even at the 7.0 gram weight, wing loading is quite a bit heavier this year as the wing area is greatly reduced over the 2015 rules. The 1.5" of tip dihedral may look like a lot for those of you that are used to a tip plate/winglet configuration, but this is actually a quite shallow dihedral angle of 20.7 degrees which matches well with the moderately large tip area.

Good luck and do lots of testing and data analysis,

Brian T.
AMA since 1972 (off and on)