Indoor Scene 1 (Oct 03) 

An introduction into indoor modelling

'FROM THE SHED'

That heading goes back a bit.  As your new Indoor Comp Sec (That will teach me to keep my mouth shut at the AGM) I suppose I should make an effort to contribute to the newsletter.

As always, we are still looking for more of you chaps out there to come on over to Digby and have a go, or at least have a look at the indoor scene.  Many of the people I have spoken to over the past many years have expressed a desire to have a go at indoor but shied away because they think they cannot cope with the fiddly bits of wood etc.

Well, that’s not really an issue.  I too have large hands and can be more than a bit clumsy moving bits about, so, over the next few issues of the newsletter, I shall try to put over one mans approach to indoor modelling.  (Mine that is)  For anyone out there that has not had a starter pack from me and would like to have a go at making and competing at the indoor meetings (And they also work at civi meets too) then drop me a mailing address and I shall send some gen.

I thought I would start with glossing over my favourite event, which is CO2 duration.  The rules are pretty simple, you can make your model any size you want, from just about any material. Cover the model any way you want and use any size CO2 motor you fancy.  Here’s the crunch though, you can only use a fuel supply (CO2) where the tank and associated pipe work does not exceed 3.25cm3.  It’s one of those old triangle things, you know, the bigger the motor the more it guzzles.  The bigger and /or draggier the model, the more power will be needed, the more power, the more it guzzles, you get the picture.

The design specification for my models was brought to a head after Mike Golby and Tony Buckingham exceeded the 7min flight time with their Brown 23 powered models a few years back, looking a bit like an over grown EZB.  I have always gone for a larger model, 40-50in wingspan, high aspect ratio and powered by a Gasparin 63 ball raced motor.  My best time as I recall to date is 6min 12sec, that elusive 7 minutes is there somewhere.  I have been striving over the past years to come up with a design that is light (My current models weigh in at c26-28grams ready to fly) low drag and will cruise at a power setting of 1000 revs or less.  If I could hit this right, I estimate that 11mins duration is possible, well, according to my bench testing that is.  These large airframes are great for slow graceful cruising and generally have a very nice glide angle.  On the down side, my flying surfaces have been built a bit marginal and lacking in torsional strength resulting in some spectacular manoeuvres through over speeding.  I have considered bracing lines, but as yet have not fitted any.

There have been many variations of model design in this class and for those who have never seen these types of model I have included some photographs of designs both by myself and from the stables of Steve Glass.  Steve has generally gone the way of a fairly small and very light airframe and low capacity motor like the Gasparin G28.  Steve’s duration models have been built with a wingspan of 24-30in and a flying weight of 13-16 grams.  His best flights so far with his latest model have been around 5min 30sec using a Gasparin 28 and KP01 5.5in plastic prop.

Ian Pallister has been using the same airframe for many years, again another large model.  This has proved to be very reliable and generally consistent in its performance.  Ian uses a Brown 100 motor with homemade single bladed counterbalanced folding prop.  It’s glide and stall recovery has to be seen. (Sorry, no picture)

As can be seen, anything goes.  Some of my earlier designs have been quite radical, with the motor mounted inside a balsa ring duct with the wing mounted on top of this and the fuselage underneath, weird?  Another used a carbon rod ‘A’ frame suspended under the wing centre section with the motor mounted inside this in an attempt to avoid stopping the motor on contact with obstacles, looked nice.  Covered in clear ultra film it looked a bit gossamer albatross.

Well that’s it for now.  If anyone has any questions or problems with indoor flying please drop me a line.  The Champs are still a month away and most of these duration models can be built in just a couple of evenings, even for me!