How Not to Do It
Here's a lighthearted look at some of the issues to do with model presentation and safety. Don't take the lessons too seriously, except for the tips...
Lesson 1 - "Use Chewing Gum and Polyfilla"
If you were rash enough to turn up to a BMFA comp with a model like the one on the left, the CD wouldn't even bother to turn you away, since your model would be unlikely to survive the journey to the flight line...
Tip: Don't bring a model unless it's structurally sound and well screwed together. Cracked spars, loose joiners, and V-tails which are ready to clap hands are all bad news.
Lesson 2 - "Soldering is for Geeks"
Or "why create the sparks on the course, if you can create them inside the model?" !
Tip: Electrical problems can cause crashes. It's worth getting it right, and that starts with the soldering. If you can't tell a dry joint from a damp fag, get somebody else to do it for you.
D-connectors are the most critical area, and are tricky to solder. Any defects will remain out of sight, so it's important to do a proper soldering job and support the joints properly. Use heatshrink, or else pot the joints with epoxy or silicon.
Chamfer the cable exit holes in the wing breaks, to prevent chafing. Also check servo plugs occasionally for fracturing near the plugs.
Finally, if you insist on fixing broken wires by twisting them together temporarily, then please do so out of view of your fellow competitors!
Lesson 3 - "Stick your servos with Blue Tak"
Failing to adequately secure your wing servos will work wonders for your models flight path - not!
Tip: many F3F'ers use servo mounts like those from Cubitts Models. These are neat, secure, and allow the servos to be easily removed. Another popular method is to epoxy the servo in a bed of epoxy/microballoons.
Avoid using silicon rubber to bond servo to the wing skin, as the stuff is very difficult to remove completely, and quick repairs become impossible.
Lesson 4 - "NEVER charge your batteries"
If you want to show a really laid back attitude, make sure your batteries are well and truly knackered before your first flight. One way to do this is to age them in a whisky cask, say for 5 or 10 years. Alternatively, stick a few 10's of amps through them and leave overnight. Knackered batteries are great for truly spectacular terminal descents...
Tip: Charge your batteries shortly before the comp, and junk them if the charge current is down when the charger is set to Auto - that's a good sign that one or more cells are on their last legs. If using NiMH batteries below say 5 degrees, it's worth treading carefully as they can drain more quickly in the cold, depending on the brand.
Note that the latest so-called "hybrid" NiMH batteries (e.g. Sanyo Eneloops, Uniross Hybrio, Panasonic Infinium) offer much reduced self-discharge compared with regular cells. A spare fully charged pack can therefore be kept in your backpack without the need for regular topping up.
Lesson 5 - "Skimp on the Radio Installation"
Some installations look like they'd be better off in an art gallery. They'd certainly be safer there (here's a virtual art gallery).
Tip: A word about carbon fuselages - these are the scourge of the F3X flyer as far as installation is concerned. When installing a 35 MHz Rx aerial in a carbon fus, It's better to have the aerial dangling free for the first flight tests, then refine it gradually as you get a feel for the range issues - an Rx with a glitch counter is very useful here. Another method is to extend the aerial - see the Samba Model site. Taping the antenna to the outside of the fus does not work!
Note that IPD and PCM receivers mask glitches, giving a false sense of security.
2.4 GHz receivers don't like carbon and can't be extended. Either order a glass layup for the business end, or stick with 35 MHz.
Lesson 6 - "Preparation is for Sissies"
Flying is fun. Sitting around on the hill with your model in bits is not fun. Do your preparation well in advance of the competition. No amount of flying skill can make up for poor preparation.