Trimming models - learnt the hard way!
At the 2000 World Championships, my dad bought me a Redko engine and a model. This was my first foray into F2D. We bolted it together and flew it in the local park (not recommended). I found it easier to fly than expected, just faster than normal. However it went wrong at my first comp, the 2001 BMFA nats. At the first hint of combat, I piled the model into the ground. Somebody pointed out that I needed to be able to fly the model without looking at it. It's fairly easy to fly a model, but put two in the same circle and it can soon get messy. Graham Ives told me how you could attach nose weight to the engine bearers. Nose weight or indeed tail weight alters the models centre of gravity, depending on how much you put on. At first I thought the model had become to unresponsive, however I think this was because I had been used to flying it in it's twitchy state. When I flew in combat, the crashing soon stopped, and I even won a couple of bouts after a while! You should trim a model to what feels comfortable for you. Perhaps a good starting point would be if you can fly simple manoeuvres comfortably, without looking at the model. When test flying, also ensure your model will loop and bunt equally. If you have very tight loops, but lazy bunts, adjust the elevator for more down action, and vice versa.
A 2p piece with a hole drilled in it makes a perfect nose weight (Don't tell QE2!). Drill and tap a hole in the engine bearers and fix the nose weight with a bolt. 1p pieces can be used for very fine adjustment.
The trailing edges of combat models seem to be prone to warping (a warp is an unwanted bend or twist). Sometimes it is difficult to see a warp, but have a good look at the wing from all angles. You might not even notice it is warped until you fly it, and it behaves funny, perhaps flying at an odd angle, or hinging in manoeuvres. The trailing edge is ideally dead straight along it's entire length. If you can spot a warp, you can bend it back by holding it in a straight position and then heating the covering with a heat gun or iron to hold it in place. Don't force it too much though, because you might snap something, and be careful with the heat!
This article was first published: 13/05/2003
This article was last updated: 13/05/2007