Hip Pocket Builders' Forum

Radio Control Forum => Jets => Topic started by: atk0110 on February 03, 2010, 01:39:12 PM



Title: EDF LIPo's requirements
Post by: atk0110 on February 03, 2010, 01:39:12 PM
I have built the Ziroli Turbinator EDF and installed the Astro 020 Wemotek 70 mm fan unit as shown on the plans. I tried a 4S 2000 20C LiPo for my first several flights and the plane just barely flew! It was on the verge of a stall all the time. I checked the amp draw and the watts and I was only getting 23 amps and about 300 watts for a power output of around 77 w/lb. After much cussing and talking to others on-line I found out that I needed to go to a higher "C" rating on the LiPo. I changed to a Turnigy 4S 3000 30C pack and I now am drawing 32 amps and 485 watts for a power loading of 180 w/lb !!! The weather has closed in here in south Jersey so I haven't flown the new set-up yet but I thought my findings would be of interest to all new EDF nuts. I have also bench tested the following: A HET fan unit with a Turnigy 75A ESC and the 4S 3000 30C pack and I am reading 55 amps @ 820 watts which would give me about 300 w/lb ! I don't know if I could keep up with that !


Title: Re: EDF LIPo's requirements
Post by: JetPlaneFlyer on February 12, 2010, 03:38:45 AM
atk,

I'm curious, what does the plane weigh?

The thing that puzzles me is that you say at 300W you had 77W/lb, so the weight of the plane must have been 300/77= 3.9lb. Then you changes to a bigger and higher 'C' battery (which i presume would be heavier) and you got 485W and 180w/lb. So weight was 485/180 = 2.7lb

Seems like the plane lost 1.2lb when you put a bigger battery in it :-\

Regardless though the point is well made, larger and higher 'C' rating allows the battery to sustain a higher output voltage which in turn pushes more amps through the motor resulting in a lot more power.

Steve


Title: Re: EDF LIPo's requirements
Post by: atk0110 on February 12, 2010, 09:14:44 AM
Steve, the Turbinator weighs 43 oz, {2.68 lbs} With the HET 2w-20-72A fan ,a HET 75A ESC, and a Turnigy 4S 3000 35C LiPo I am getting 48Amps @ full throttle and reading 670 watts on my Astro meter for a power loading of about 250 w/lb All I need is to get rid of approx. 4 ft. of snow on our field now !!

Al