PHOTOS: RON SCHWARZKOPF PHOTO: ANDY ZANER
Moving on to the next level, with chines, three-wing designs and oddball things like Tacit Blue, requires a pretty fancy method called vortex lattice. Bob says that the best current, and free, program to do that is AVL
http://web.mit.edu/drela/Public/web/avl/, which is continually upgraded and im- proved. When he did the analysis of the plane I was building, the measurements and printouts were way beyond my abilities and very educational in how parts of the air- frame influenced other parts. AVL has a pretty minimal amount of documentation, and it’s written by an engineer for other en- gineers. It also has a command line inter- face, so it takes a bit of effort to learn how to use it. Finally, we get back to the root of mod-
eling (hey! it worked for Spaceship One!) and that is a chuck glider. It is simple, not just inexpensive—but cheap, and fast. Do a quick calculation and then move around a piece of clay to find the correct c.g. Bob’s next suggestion is then to build a flat-plate foamy R/C model with Depron® sheet, and add an edf unit stuck in the fuselage or a prop on the nose or tail. You’ll want both a top view and side view profile of the fuse- lage, just a simple “+” cross section, though if you want to get really fancy, you can build up a box fuselage. There are a huge number of plans and ideas to be had at
http://www.parkjets.com/free-plans, and kits at
http://www.6mmflyrc.com. Once you have the foamie model, take it to
the field and fly the stink out of it getting not only a feel for the correct c.g. “feel” but for control throws and oddball things like its vi- sual on final approach. (Why do I feel like slapping my forehead at the simplicity of this approach?) Given the prolific nature of one of my club mates with Depron®, I’d guess less than a week of evenings would get my odd-
Looking down the T-38 fuselage, the cockpit details (at left) can be seen (all scratchbuilt) as well as those sexy area-ruled curves in the fuselage. Ron Schwarzkopf’s “canoe” (above center) taped in place on his Bandit. Smoke fluid capacity has yet to be determined, but lets him get ready to have a “smokin” time. The simple box-shaped fuel cell inside the canoe (above right). With carbon fiber for strength and BVM fittings for simplicity, this simple design should work on a number of airframes.
ball canard-edf want-to-do airplane to the field with Depron® and an edf unit ... hmmm. Anyway, with all of this, it helps to re- member the old adage: “Nose heavy air- planes fly poorly, but tail heavy airplanes only fly once!” so keep it conservative for the first flight, regardless of how you figured out the c.g.! Thanks for the suggestions, Bob! Several months ago, I reported on Mike
Neff’s Space Shuttle-launching 747, con- structed from Depron®. Well, Mike’s done it again, but this time with a 727. This one is from cardstock and Depron® and is designed as an indoor flyer. A video can be found at:
http://tinyurl.com/84lbxmx, as well as many more videos of his Depron® fleet. Continuing with the edf theme, Andy
Zaner continues to impress with his 144- inch long T-38 construction thread on the E- Zone
http://tinyurl.com/87dxkxz. The more I read this thread, the more neat things are discussed and shared that can make build- ing easier for all of us, from fabrication of tools for shaping blue foam to paint-on sheeting/shell material. This is going to be an interesting materials course when the planes take to the field, and some of the ma- terials are then tested. It is a “worth your time” thread to check in on regularly! Since we are getting close to our “smokin”
flying season, and many flyers like to run smoke systems in their jets, the problem of how to get a smoke-fluid tank into a tightly packed fuselage (BVM Bandit) bothered Ron Schwarzkopf—so he designed an exter- nal tank! Ron likes the process of molding, so he designed a canoe shaped fairing to go around a basic box-shaped tank and rein- forced the fiberglass with carbon fiber. Looking at the photos, I can tell he has
been looking at photos of England’s Red Ar- rows and their BAE Hawks, since beneath the middle of the fuselage is a canoe shaped
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tank! Since the tank is external, it can be placed right on the c.g. and have no effect on the balance of the airplane, and should look great! I for one am looking forward to some progress photos! Given the increasing size of airframes, and
the amount of detail that can go into them both space, and weight wise, it is no surprise that someone (Churchill Creations in conjunc- tion with YT International in the U.K.) has come up with an animatronic pilot bust! While individuals have done one-off versions, these are production items and should be readily available. A video can be seen on YouTube at:
http://tinyurl.com/7x5ptbl showing some of its capabilities. Additionally, a “how-to” can be found as two separate posts on a UK forum. They are at:
http://tinyurl.com/6n6jg6m, and
http://tinyurl.com/7vk63yu. While originally developed for R/C tanks,
they can easily be placed in some of our larger jets. Control is via a closed loop elec- tronic circuit, and the pololu serial servo controller is available in 6-, 12- and 18- channel versions with the 12-channel one costing only $30.00. The figure shown in the YouTube video is not integrated into an R/C system, it uses pre-programmed posi- tion points on a closed loop, and just goes to each point for a certain amount of time and then at the end of the loop, it starts all over again. The controller (pololu) can be purchased
in several versions, and I can see one being programmed to move the turrets and guns on a bomber as it flies past. Who will be the first? More information on the controllers can be found at:
http://tinyurl.com/8y5c5ob and much more information with links can be found at:
http://tinyurl.com/7pg3ysz. Well, I’m out of space, so until next time:
Stay warm, keep busy with the building pro- jects, fly safe, and trust in thrust!
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