Accu157
Mar 02, 2007, 02:40 AM
Over the summer, I will do my very first scratch build, from the ground up. A Cessna 182, semi-scale, with sedate performance. I'm aiming for lightweight construction, and something that will look like a Cessna, but still look like a model... know what I mean? It's not approaching a really nice scale model, but it will be pretty. You'll see the stringers, not a whole lot of sheeting, just nice.
By light, I mean light, like parkflyer wing loading, and parkflyer performance. I intend to use a 400 watt class motor, and I'm after sedate performance, So I settled on about 55-60" in span, and around... 4 lbs ready to fly weight tops. Maybe a larger airframe, we'll see in a bit. .5:1 thrust to weight is A-ok. .75:1 would be optimal, and I can get that from this motor (Mega 16/15/3 with a MEC mini-gearbox). This isn't like the .40-.60 size scale models you see cruising at 60mph, it's slower.
I'm thinking top speed will be around 50 mph in a dive, at the most. Kinda like the Super Miss but a little bigger.
Otherwise, I'll just start penning a design over squares using whatever intuition strikes me as I pen it in. I was thinking of doing a construction where there is a box structure for the fuselage on the inside, and a stringer-supported scale structure on the box. I've seen this style before, I like it and I think it'll provide sufficient strength to weight. Wing is of no concern... I've got that squared over. I just wonder what airfoil I should use... nothing fancy, Pfft, Clark-Y? :p Rudder and elevator are no concern either.
I want to isolate these areas to a single strong frame: the motor, battery, wing mount, and the fuselage frame will be like a decoration around this basic frame. I am capable of designing models by now, I just like some input, suggestions on what to avoid. I might freehand a lot of the design without plans, so this is a one-off model.
By light, I mean light, like parkflyer wing loading, and parkflyer performance. I intend to use a 400 watt class motor, and I'm after sedate performance, So I settled on about 55-60" in span, and around... 4 lbs ready to fly weight tops. Maybe a larger airframe, we'll see in a bit. .5:1 thrust to weight is A-ok. .75:1 would be optimal, and I can get that from this motor (Mega 16/15/3 with a MEC mini-gearbox). This isn't like the .40-.60 size scale models you see cruising at 60mph, it's slower.
I'm thinking top speed will be around 50 mph in a dive, at the most. Kinda like the Super Miss but a little bigger.
Otherwise, I'll just start penning a design over squares using whatever intuition strikes me as I pen it in. I was thinking of doing a construction where there is a box structure for the fuselage on the inside, and a stringer-supported scale structure on the box. I've seen this style before, I like it and I think it'll provide sufficient strength to weight. Wing is of no concern... I've got that squared over. I just wonder what airfoil I should use... nothing fancy, Pfft, Clark-Y? :p Rudder and elevator are no concern either.
I want to isolate these areas to a single strong frame: the motor, battery, wing mount, and the fuselage frame will be like a decoration around this basic frame. I am capable of designing models by now, I just like some input, suggestions on what to avoid. I might freehand a lot of the design without plans, so this is a one-off model.