A return to model building and flying. Part 21
Re-writing rules and a kit
After a week getting over a cold when I didn't feel like doing much I managed to write up some proposed rule changes for our club control line comps for next year. I can't see the point in calling something a mini-Goodyear class, when it's just in effect, a time trial with any sort of 1.5cc engine, any sort of model, unlimited tank size, and a non standard way of measuring the lines. And the same applies to Goodyear.
Don't get me wrong, it's fun, if a little exhausting with an engine that has a totally unpredictable length of engine run. It's just the fact that if I had known the ground rules at the start I could have built a much more suitable model, hence the idea of writing things down in black and white so we all know what we are supposed to be doing. The process has already caused some lively discussion. And the outcome is bound to be interesting.
After discovering that the Tutor will also do simple aerobatic manoeuvres, it's a really strange experience being able to throttle back during the downward legs of a lazy eight, in my usual fashion managed to loose line tension in a strange place and end up with the model plummeting strait downwards flat out with the lines drooping towards the ground. I was faced with the choice of either watching it turn into a pile of bits or try the last ditch trick of grabbing the lines in my left hand and jerking them back in an attempt to get some control. As we are talking about three lines and no way of knowing which one is going to end up the shorter, it is truly a last ditch desperate action. As turned out it was down, and if I had a little more height it would have pulled out inverted with some chance of regaining control. I was not quite that lucky, the model hit at a shallow angle inverted. The only casualty was a broken prop and needle valve assembly on the OS 20. More of an, Ouch! on the pocket than anything else. So I could say that grabbing the lines was worth it, doing nothing would have been a disaster.
The next day a replacement spray bar assembly was ordered from John D Haytree, another business that does not have a web presence (mores the pity, as he carries spares for about every engine known to man or beast), which promptly arrived a couple of days later; and then I set to work making an alloy brace to support the needle in the case of another such incident.
The new goodyear model flies quite well thanks to the much reduced airfame weight. Two problems have cropped up, the first, I made the wing too thin for only covering it in Orocover, which incidentally does seem to diesel fuel proof as advertised, It develops a quite graceful curved dihedral in flight and does a good impression of a bird flapping it's wings in blustery conditions, all slightly alarming the first time I experienced it, but the model seems to just keep ploughing on regardless. The second problem is caused by all the weight I have distributed below the wing. mini pipes, alloy U/C with a large wheel for our not too smooth field, all add up. The result is the model flies outboard wing up, adding to the instability in blustery conditions. This is a problem I have not thought of a solution for at present, but I will.
I have been kindly given a Hallem Models kit by a club member, a Swift Profile Stunt to be precise. For anyone who does not know of Hallam Models, the make a range of simple profile type control line models which come in a plastic bag full of pre-cut bits, with no plan, just a few sketches of how thing go together. They also sell a few basic C/L things like lines, handles, tanks, and bellcranks. Most of the stuff you would need to start in C/L, or if you wanted to try your hand again after a few years layoff, and all at reasonable prices.
The Swift was not exactly what you would call a high precision, high quality kit. A bit of bodging or truing up is needed to get things fitting together correctly, the wing ribs in my case where not tapered towards the tip as they should be. There were three ways I could have corrected this but as I had already glued a couple of ribs in place, I just glued some sandpaper to a strait strip of wood and sanded the whole lot to shape in-situ. As these kits are not exactly expensive by today's standards, this sort of inaccuracy is not really a problem, and can even be a usefull learning experience for anyone remotely interested in building as opposed to just buying. So far, it has gone together quickly and easily and proved quite enjoyable to build. Pictures next month.
Unfortunately Hallam Models have no website, so all I can do is show this illustration of some of the models and give the address and phone number. Small enterprises like this really do need supporting as they attempt to keep the C/L flame alive. The leaflet is quite old and probably out of date but should give some idea of what is on offer. There is even an asymmetric speed model available now, which is not illustrated here.
Here is a price list I picked up at the 2005 UK nats
For more details: