sfw2523i

Introduction:

Trying to reproduce the success of the sfw2423 in inav form.

Components:

• Dollar tree foam board

• 2x 9g servos

• Emax 2205 2300kv motor

• Beitian 220 GPS

• Frsky xm+ receiver

• 5v regulator only for servos

• FX799T 200mw vtx

• Furibee 30A ESC

• Runcam Swift camera

• Fullspeed F3 omnibus flight controller

Conclusion:

228g dry. It came out a lot heavier than I was expecting.

Update 11/4/20: The maiden did not go well at all. It crashed fast and hard due to CG issues. Luckily, nothing got broken, so I am taking the camera/vtx off and trying to find the right CG before attempting another FPV flight.

Update 11/8/20: I found the correct CG and it flew ok, but not great. After some thought, I realized that the issue was probably due to the longer nose and the extra weight of the camera and vtx all the way in the front. I initially made it longer to be able to use smaller batteries and balance the CG, but now that I see the ill effects of a long and heavy nose, I decided to shorten the nose by 2 inches. The effects were really great. It flies great now and with the FPV gear, it is probably my favorite FPV plane. It actually cruises around slowly and is really efficient. With a 3s 850mah, I was able to fly 10.5km and 13 mins flight (slow cruising) landing at 3.6v. I'm not sure what the max battery size it can take is yet, and I may also try a 4s at some point as well.

Update 11/15/20: Tested it on 4s 850mah today and it flies better for sure. Unfortunately, I used some older 4s batteries and battery life did not improve at all.

Update 11/17/20: Tested it with a 4s 1550mah. It was heavy and the flight did not go well. CG was off a bit, but even after correcting it, I could tell the wing loading was too high which caused a rough landing. It didn't help that it was windy, but I didn't feel that it would've flown well on a calm day either. I think I'll have to go down to 1000ish mah to see if it works better. This is a shame as I was really hoping it would be able to share packs with my 5" quads.

Update 11/21/20: Tested it on a 3s 1800mah today and it was flyable, so I think this is about the limit for this plane. Unfortunately, the battery was very old, and I came down after 12 mins with the voltage eventually resting at 3.8v. Unless it's for a long mission, the best flying combo is still the 3s 1100mah.

Update 12/3/20: Did some wing loading calculations today as follows. Plane is 7.7oz dry with a wing area of .5sqft. 3s 1000mah is about 3.3 oz which means it comes out to about 22oz/sqft. The 4s 1500mah is about 6.4oz which makes the total come out to around 28.2oz/sqft. Sporty planes keep the wing loading to around 20oz/sqft. 25 makes it harder to fly and 30 approaches scale planes.