A return to model building and flying. Part 12

A combat wing and all that

February 2005

The Danish Challenge did a good impression of flying together (no pun intended). The must difficult job was making a fuel tank, in which I promply reversed the the vent and feed pipes. Fortunately in this type of tank it doesn't matter too much.

For the first time I have covered a complete model in a plasic film, well, Solartex to be precise. I still have mixed feelings about it. The main thing that unnerves me slightly, is the fact that it is never is really drum tight and tends to change it's tension slightly for no apparent reason. And the big Gulp! I tried to surpress, was not easy to get over when I saw the price. However, having said that, it certainly is easy to apply, and produces a finished airframe in a very short time.

combat

The fly in the ointment turned out to be the paint I used to fuelproof the vulnerable engine pod area. It was the same paint I had used on the Stinger so didn't expect any problems. Oh how wrong can anyone be. I should have known something was wrong when it seemed to take a long time to dry and still felt slightly tacky a few days later.

combat

Came the end of the week and it was the monthly team race. I was eager to try out the modifications and repairs I had made to the Stinger. having noticed that the tailplane had a developed a warp like a dogs hind leg, s biy of emergency surgery had made a slight amount of permanent up elevator on the right side. I had changed the original design to a half elevator on the left side to make iteasier to build. I was also wondering if this warp had anything to do with it's nasty tendency to nosdive after anything but a perfect launch?

I had also been sent a model by Herbert Garritsen, a mini goodyear Deerfly, made in anger after loosing his job, "So it should be fast," in his own words. A kind gesture which I intend to repay by trying to fly it well.

mini goodyear

So on the day I had thee models, a sudden jump from the zero models of a few months ago. The weather was cold but unusually calm, with the sun showning through as the day went on (most peculiar). The first round had the model flying much better, although the engine had decided to not start quite so easily. Second round had the tank run out at 49 laps. It was going to be touch and go if I could make the finish on one tankfull. After a refuel, I twisted the needle a little leaner and not only managed the 50 laps, but just kept going to what must have been around 80; I lost count. looks like I need a slightly smaller tank.

The end result was second place. I was well pleased; especially as ther are no repairs to do this time.

Herbert's Deerfly was causing me trouble, or it would be truer to say the PAW 1.5 was giving me trouble. I just could not get it to start. and was getting bruised and sore fingers in the proces. On such a small model there is no easy way to hold the model so in effect I had to hold the engine with copression screw digging into my inner thumb. Not so bad if the thing starts within a sensible time, but if it's being stubborn sore hands all round.

Another thing I do not like, is that moderm props seem to be made of a hard plastic that is moulded to a razors edge, something that I do no think is necessary and downright undesirable for fun flying. I spend a lot of time taking the edges of them. What I would give for a supply of the old bendy nylon Tornado props. I manged to get hold of yellow prop that marked F.K. made in W Germany, at the local model shop that fits the bill. I just wish they carried the full range, not just a handful burried under the others. It would also be nice if thet carried small props and pitches greater than 6", in any make of prop.

However I digress. In the end I screwed the needle in all the way just in case it was just flooded, and tried to run off the excesss. To my surprise it started and kept running. It obviously had a short needle, something I can alter, but difficult on the field. I decided to give my hands and arms a rest and try again another day.

Then there was the combat wing!

This has brand new unrun PAW 19 bolted on the front. Even more sore fingers as the engine was so tight I had no feel for when it was about to fire. and more comp screw digging into my thumb, The contra piston is also extremely tight and will sometimes not back off even with the engine running. I get the feeling this maybe a, "Friday afternoon job." As we used too say about things that are not quite finished right.

Eventually I did get it run at tank through by using a large diameter prop to give it a bit of flywheel effect. I also noticed my hand were not only covered in the usual concoction that spews out of a diesel exhaust, but also copious amounts of blue paint. The stuff was coming off like it had been dowsed in paint stripper. Bizarre, as on the Stinger the same paint is still untouched.

After wiping as much of it off as I could, and to placate the rest of the assembled throng hanging around waiting to see it fly, I gave it a whirl. The model feels very right even with the engine running very off peak. The moment of euphoria was short lived, as the engine suddenly slowed down and stopped in one of those, seized sort of ways. Fearing the worst when I picked it up, it felt very stiff. I spent the next 10 minutes working fuel through it until things felt a little freer. To my relief It started and ran another tank through.

After a break and a drink in the club hut, I was about to call it a day, when Pete Catlow persuaded me to have another go. I didn't really need much persuading, even though the aching arms, cuts and bruises where telling me otherwise. This time I made sure the engine was really undercompressed and burping. Which state it maintained for the rest of the flight. With no wind and the model behaving well, even in this state I could wave it around the sky quite happily.

So I packed up and went home a happy bunny. Now all I have to do is sort out that ghastly paint, and the short needle



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