I wanted to create a special thread where we put on our thinking hats and post things that apply in electric. I believe that if we want to go electric we need to build from the ground up with that in mind from get go. So let's see things that we can use to make a better electric bird YaaaaYYYY
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Fuselage building:
We do not need the thick doublers no more 1/16 ply can and should be substituted for 1/64 ply or even some 120g/M2 plain weave carbon fiber. We do not need anything that reduces vibration or design for high vibrations like the heavy duty engine crutch we used in IC motors. And yes there is no oil to worry about or increase in weight due to oil soaking through the balsa in time.
We do need to think battery position the balance the model longitudinal and lateral. We do need to think about cooling the electric components.
Wing and tails
Building wise it will all remain the same however the airfoils can get thinner and the wig tip thinner yet to get a better lift distribution and better performance for flying in the wind and reduced power consumption. Retracts are definitely an option. With active timers the motor run band can be anything we want it to be so there might be a good time to start some experimentation on new airfoils with better lift distribution that behave when you fly in the wind. Yes we still need the lift to carve the corner but you can still get a lot of lift from a thinner airfoil too.
Power plant.
Yes we run electric motors now and unlike IC they develop max torque at low RPM opposite the IC counterparts. The motors can spin both ways and there is some exploration going in that direction with CCW props but since we are so used to the trim and yaw response feel of a CW prop and we are used to trim the models for CW props we tend to go to the Devil we know.
Light props are the way to go. I may add that single blade props are the most efficient power wise but since they are very much non-existing except for very special applications. 2 blade props should be the best for ow. You can make composite props that weigh similar to the 3B 12in hollow props in 2B 13-14in quite easy.
Igor will kick my ass on this one but here we go. I crunched some number in the prop thrust calculator and the most power efficient props for electric are high pitch and high diameter and the motors run low RPM (go figure they develop more torque at those rpm). I think we have to consider exploring this avenue.
Another detail that needs exploring is in the motor selection. As motors increase in size they work easier respond faster (especially if you go low rpm where they have more torque) but also their weigh increase. Now on the opposite side you use less electrons and batteries get lighter, and the ESC could get smaller and lighter but overall the weight of the system kind of remains the same (I call this the rob Peter to pay Paul kind of thing) . I crunched some #with a 4250 motor 13x8 prop on 4S at full rpm and a 5.5 min it was using 2100mAh at 21A that kind of started to open my eyes and question the status quo. 4S 2200-2500 are quite common and they are cheaper. Would you rather have odd low production run expensive batteries or go opposite.
Lets put the thinking hats on and find out what is worth wile.
Traian