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FT3D - can someone measure their AUW?

Brett_N

Well-known member
#1
I just built another one of these after bashing and crashing the first one.

Same exact power plant, servos and batteries from the first one went into the second one. (I forgot to weigh the first one, but....) my AUW with a Zippy 3S 1600 comes out to 20.8oz. In Ecalc, based on my power plant, it's giving me a 187W reading, which is 6:1W/oz - which is really low even for a trainer.

Just confused based on the common "w/oz metrics"

(oh, power plant is a generic 40A ESC, DYS236 x 1120 and a 10x45 APC prop)

I'm just wondering if this one came out heavy as lead - I tried the "cover with packing tape" method, as well as using eopxy in strategic weak points...guess I'll just see how it flies.
 

Merv

Well-known member
#2
I'm just wondering if this one came out heavy as lead.
Sounds under powered to me.

My FT-3D AUW is about 27oz. I’ve made the wing a lot bigger than stock. I’m running a Turnigy 3730 1000kv, I think about 580 watts, with a 12x3.8 slow fly prop. 2200 3S 50 amp ESC. Has unlimited vertical. Can hover @ 60% throttle. Can knife edge forever. If you can’t tell, I like it.
 

Brett_N

Well-known member
#3
I'll stick the ol' watt meter on it tonight. Doesn't make any sense to me (maybe ecalc had a goof in it) I can always try another prop. On the first one on the exact same setup the flight performance was spot on - maybe I did the math wrong somewhere.
 

DamoRC

Well-known member
Mentor
#4
20.3 oz = 1.3 lbs

187w / 1.3 lbs = ~150w/lb.

From the web below - seems to me you're good!

General power guidelines.

Here are some Watts per pound values that should put you in the right ballpark for your particular plane...

Less than 50W/lb - very lightweight / low wing loading slow flyer.
50 to 80 W/lb - light powered gliders, basic park flyers and trainers, classic biplanes and vintage ('Old Timer') type planes.
80 to 120 W/lb - general sport flying and basic/intermediate aerobatics. Many scale ( eg warbirGeneral power guidelines.

Here are some Watts per pound values that should put you in the right ballpark for your particular plane...

Less than 50W/lb - very lightweight / low wing loading slow flyer.
50 to 80 W/lb - light powered gliders, basic park flyers and trainers, classic biplanes and vintage ('Old Timer') type planes.
80 to 120 W/lb - general sport flying and basic/intermediate aerobatics. Many scale ( eg warbirds) subjects suit this power band.
120 to 180W/lb - more serious aerobatics, pattern flying, 3D and scale EDF jets.
180 to 200+W/lb - faster jets and anything that requires cloud-punching power!


DamoRC
 

Brett_N

Well-known member
#5
Hahahaha - I just realized I was doing watts per OUNCE - changes the game dramatically when it's watts per POUND LOL