ironJaw

Greg.

I am trying to establish a weight budget for my research model.

I am using the AXI 5330/20 dual tandem motor.
I am using a Mejzlik 26-10 Prop
I am using two Jeti advance plus esc. units.
and I am using two pairs of polyquest 6000 LI-Po 5s batteries.
My present weight with computer, RCATS, and another package is 42 lb.

The take-off is rapid and gets to 800 ft is short order.  The rpm at cruise is between
3800 and 4000.

we do no fancy aerobatics just level flight, variable bank angel turns, and stalls both clean and dirty.

The model is 100 in span,  1881 sq. in. area, basic dry weight 30 lbs.  It was designed for 100 cc engines
the wing has a symetrical airfoil approx 12% thick.

at the present weigt of 42 lb. I can see a slight angle of attack in the fuselage in straight and level flight.

The wing and stab are a 00 incedence and at cruise I can see a slight angle of attack in the fuselage.

I am looking for how much more I can load up the model and still make it safely flyable.  Granted the takeoff
run will be longer and climb out slower, but it stll has to remain within good visibility range.

Things I can do.

  Rotate the wing on the tube a couple of degrees to acheive a better lift/drag ratio.
I can lower the inboard flaps a couple of degrees to acheive more lift with min. drag incr.
I can raise the outboard ailerons a couple of degrees to alleviate tip stall.

do you think I can safely go up another 10 to 15 lbs in payload before I get into serious trouble?

I have static loaded the wings to over 8 g. at a weight of 42 lb.  so I am not too concerned about the weight otherwise.