I've just built a Quest Flat Cat Boost Glider and while I was completing it I was already thinking - "How can I make a bigger and better one?!" (I have a basic knowledge of how they work - that the CG must be at about 50% of the wing chord when gliding and the CG must be at least one body diametre infront of the wing when boosting etc - so I aint that much of a rookie!). So, looking at what balsa I had available, I knocked up another 'bigger and better' one kinda based on the Flat Cat, the old principle - "If it looks right it is right", the odd "Guestermation" and a few ideas of my own.
It is longer: 600mm long, with a 700mm wingspan. I used 1/8th balsa for the wings with 15 degrees of dihedral on the wingtips - strentherned with 1/16th ply. 2/32nd was used for the stabiliser and rudder assemblage 1/2 inch by 1/4inch hard balsa strip used for the fuselarge (which was shaped, i.e I tapered it so it thinned out towards the tail). The stabiliser and fin were made bigger too - the stabiliser (300mm wide) was also mounted about 1/4 the way up the fin as so not to be in the 'dirty' or turbulent air from the wing. All of this was epoxed together bar the wings which are attached by nuts and bolts. I copied the same method as the Flat Cat to attach the booster pod and space in the nose to mount and additional nose weight. It probably weighs in at 50 - 60 grams without the booster pod. I also built it with the booster pod slung 'underneath' the glider - so it has a conventional layout - stabiliser and fin on 'top' rather that 'below' the fuselarge (as on the Flat Cat).
My plan was too use the booster pod of the Flat Cat and stick a C5-3 motor in it. But....when I looked back over some info I had on a boost gliders in a book on Space Modelling (Published by Traplet), it recommeded a wingspan of around 400mm (!) for boost gliders and a area of 300 to 400 cm2. Now im no genius but at 700mm that gives far more wingspan and gives far more area than suggested! This led me to rethink my plans a little! Is this beast of a glider gonna boost up to a decent height or crash about 2ft from the launch pad coz its too heavy or creates too much drag? I have thought about building a bigger booster pod, with a D12-3 in. But will the higher impulse just turn the glider to matchwood upon launch? Oh, my finally though was am I ever gonna see it again if it does launch - will it just glide off into the horizon never to be seen again? Will I need to stick some kind of de-themalisers on it?
Any advice and or suggestions would be warmly welcome,
Thanks,
James
It is longer: 600mm long, with a 700mm wingspan. I used 1/8th balsa for the wings with 15 degrees of dihedral on the wingtips - strentherned with 1/16th ply. 2/32nd was used for the stabiliser and rudder assemblage 1/2 inch by 1/4inch hard balsa strip used for the fuselarge (which was shaped, i.e I tapered it so it thinned out towards the tail). The stabiliser and fin were made bigger too - the stabiliser (300mm wide) was also mounted about 1/4 the way up the fin as so not to be in the 'dirty' or turbulent air from the wing. All of this was epoxed together bar the wings which are attached by nuts and bolts. I copied the same method as the Flat Cat to attach the booster pod and space in the nose to mount and additional nose weight. It probably weighs in at 50 - 60 grams without the booster pod. I also built it with the booster pod slung 'underneath' the glider - so it has a conventional layout - stabiliser and fin on 'top' rather that 'below' the fuselarge (as on the Flat Cat).
My plan was too use the booster pod of the Flat Cat and stick a C5-3 motor in it. But....when I looked back over some info I had on a boost gliders in a book on Space Modelling (Published by Traplet), it recommeded a wingspan of around 400mm (!) for boost gliders and a area of 300 to 400 cm2. Now im no genius but at 700mm that gives far more wingspan and gives far more area than suggested! This led me to rethink my plans a little! Is this beast of a glider gonna boost up to a decent height or crash about 2ft from the launch pad coz its too heavy or creates too much drag? I have thought about building a bigger booster pod, with a D12-3 in. But will the higher impulse just turn the glider to matchwood upon launch? Oh, my finally though was am I ever gonna see it again if it does launch - will it just glide off into the horizon never to be seen again? Will I need to stick some kind of de-themalisers on it?
Any advice and or suggestions would be warmly welcome,
Thanks,
James