Design Thoughts

So we need to achieve quite a few things in this design/designs.

• Good training flight characteristics.
• Multiple power sources (electric/IC)
• Possible modular design. (different wing types on the same fuz)
• Use of modern materials.
• Good looking and appealing design form (think Foss Wot).
• Manageable size. (makes the airframe more robust whilst taking up less building and storage space, uses less materials).
• STEM suitable (Science, Technology, Engineering, Math) JR
• Emerging technology capable such as FPV etc JR

Please add to the list.

@pylonuk Is technically interesting to STEM students. FPV Flight controllers etc ?

How about using foamboard?

I've never made anything from it yet, but I've seen models that were made from it and it seems to be very simple to build a model from it.

@pylonuk got to be Depron!

@rong Ron for someone who has been building for 55 years (me) depron is a modern material !!

@pylonuk 😀

quick and simple to build to maximise the chance of a successful build 

single source components and materials, reduce time needed to get all the parts together 

My thoughts on the STEM Trainer are:

Design - 1400mm ws. Ideally high wing but that doesn’t appeal as much as shoulder or low wing, so a design that flies well based on shoulder wing but could be adapted for low wing later. Wing with fairly wide chord and parallel with some dihedral and strip ailerons, ClarkY or similar flat bottomed airfoil, not too thin. Alternative wing based on KFm profiles! Fuse with not too short nose for easy battery placement (unlike WOT) and not too short tail moment arm. Tail surfaces nice balanced size. Basically I’m think F3A with parallel chord wing - why F3A? because they are inherently stable!

Build - Depron has to be main material as it is cheap, easy to get and easy to build with and it’s ‘modern’. KFm profile wing dead easy to build, box section fuse ditto. Aim to be able to build in a day.

Power - Electric. 

More thoughts to follow

@jono We could mots likely arrange a 'one stop shop' if that was required but we should also keep in mind that all materials selected should be generally and easily available, maybe even to an extent outside of the model trade.

@pylonuk the beauty of Depron is that it easily available, you don’t have to worry about different grades, it’s cheap and easy to work with plus allows for quick builds. IMO Depron is a better build material than a lot of foam board I’ve seen, even though FliteTest use it for their vast range of models. My feeling is that any design should be based on 6mm and 3mm Depron as these are the most widely available thicknesses.

So my thoughts, drawn out into some form of basic model. This is loosely based on a model I had back in the 60s and was my first RC 'plane (!) powered by a Cox PeeWee 020 and 'controlled' by an RCS Guidance System III with an Elmic Compact escapement which gave it a 'kick up' elevator. The model even though only 20" wingspan flew really well. So I thought well why not use that as the basis so here goes.

The original model plan

 And here is my redrawn version at approx 3 x the size (so just under 60" or 1500mm). 

I have allowed for either a shoulder or low wing version and am working on making it so that these are interchangeable. It is designed to be built in Depron using only 3mm and 6mm sheets but with balsa/ply strengthening as required (U/C mount, fuse doublers etc).

Alternative tail, straight edges = easier build?

@rong I really like these little Ken Willard designs, I have looked at a few for a vintage electric pylon racer