I don’t care about a BEC. I am also using a Mauch power module that gives me plenty of options. Based on Ecalc numbers, a 40 AMP ESC for the drive motor should be fine. Electronically, I think ESCs operate similarly. I am assuming any reputable brand will be suitable.
What AMP battery are you using and what is the predicted flight time at 11.5 KG?
Thank you,
Dave
I have a pair of Foxtech 12500 mAh 6s 3C (37.5 A constant) li-ion batteries for the main system and cruise motor. An AT4130 KV230 and 17x10 prop with a current pull of ~28 A gives me a 1:2 T/W ratio which should be plenty including buffer as I assume cruise will be closer to 1:4 or 1:3 T/W at 10-16 A depending on how much lift the airframe actually generates at airspeeds of 18-20 m/s.
For the VTOL modes I have a pair of Turnigy 5000 mAh 6s 25C (125 A constant, 250 A max) lipo batteries. The 4 V505 motors with 17x5.8 props pulls ~43 A for 12kg of thrust (hover a.k.a. 1:1 T/W), ~124 A for 2:1 T/W and could go up to a max of 200 A (limit of the VTOL PDB design) nearing a 3:1 T/W.
My forward flight time estimate based on 80% battery capacity is around 45 minutes. My hover time estimate is 5.6 minutes. Neither of these estimates include air drag from a sling load but do account for its weight in the MTOW.
I gave plenty of room of to play on purpose for safety and proof of concept since it is a heavy bird. I will likely downsize the VTOL batteries to make more room in the fuselage after I have real flight test data. Please point out errors and/or things overlooked if you spot them.
Cheers,
Christian
I made some parameter changes to my trims. Since the aileron appeared to already have near maximum throw capability, I will try adding some rudder into my turns to make them sharper when needed. I also lowered my ARSPD_FBW_MIN to 10, corrected my ARSPD_TYPE to Analog, and, set up for calibration.
ARSPD_AUTOCAL,1
ARSPD_BUS,1
ARSPD_FBW_MAX,20
ARSPD_FBW_MIN,10
ARSPD_OFFSET,2101.745
ARSPD_OPTIONS,0
ARSPD_PIN,15
ARSPD_PRIMARY,0
ARSPD_PSI_RANGE,1
ARSPD_RATIO,1.9936
ARSPD_SKIP_CAL,0
ARSPD_TUBE_ORDER,2
ARSPD_TYPE,2
ARSPD_USE,0
Since the weather turned bad, I decided to improve my battery canopy look with some Krylon Fusion Red Pepper spray paint and some hand-cut vinyl based off one of the MFE window decals. The hatch latch cover is sticky-back foam from Michael’s Craft store.
Looks great. Thanks for the update.
I meant to post photos of the carbon fiber motor mount plates I created but I’ve been bogged down with other projects for a bit. These new plates allow the V505 motors to fit on the tarot mounts I have. The stock Tarot plates are 2.5 mm CF but I chose a 3 mm CF sheet since supply was easier. I used a jigsaw with carbide tipped blades, a small drill press, and a rasp file. It wasn’t too difficult for me putting my woodworking skills to use. I absolutely recommend use dust suction and a mask when working with CF.
Cheers,
Christian
That’s some fancy carbon cutting, Christian! It looks great!
I am ready for my AS sensor calibration flight but the weather has not cooperated.
Cheers!
Thanks, it will get the job done I think.
Weather here has not been great for the past 2 weeks but now it is getting more stable just in time.
-Christian
I ordered a second Fighter as a spare from FPVKING Store on aliexpress on Jan 24 and until yesterday I thought it will never arrive. I opened a dispute about a week ago and then out of nowhere it appeared at my adress yesterday. It must have been stuck in NL at customs for ages. I don’t know why.
So I am happy to have my spare plane in the hangar now 
I suppose it is good that it was a spare and not a primary you were waiting on!
Christian thats true! But I am very glad to have the spare one in case of a crash or something.
Konrad,
I am glad to hear that your second Fighter arrived! Logistics from China is getting better but still not running properly.
Cheers!
I got another flight on my Fighter VTOL today. It was mostly to calibrate the air speed sensor but I also wanted to slow it down some from my previous flight so we’ll see what the log looks like. The transitions work perfect every time and it just flies superbly! I flew in CRUISE and LOITER modes this time.
It looks like the AS sensor is working fine so I’ll enable it for my next flight test. Since I was at mid-throttle, I was expecting the ground speed to be closer to 15m/s since my settings are below. Perhaps it will fall into place when the AS sensor is enabled.
ARSPD_FBW_MAX,20
ARSPD_FBW_MIN,10
My average forward flight power level was about 356 watts at about 20m/s. I’m still going to target 15m/s as the plane was rock solid even with the 10mph wind.
Greg,
The plane looks great. I know it’s silly but the detail around the canopy brings a distinctive character to your plane and build.
Great to read it is very stable. I am bit surprised to see you amps at 15.3. What is your drive engine and prop size.
eCalc is suggesting i’ll be around 10 amp at 18/ms/s, which is based on 12s power.
Thanks for sharing.
Hi David,
Thanks!
My forward flight power system is comprised of parts from previous projects. The AXI 4120/18 (515kv) motor uses an APC 15x8 e-prop. I also had an older Turnigy AE-100A ESC available which was a re-labeled HobbyWing ESC. It will be overkill for the 1500 watt capable power system as the Fighter will only be using partial throttle for cruising around while mapping. Remember that I’m using 6s, not 12s on my build.
So for now, my 356 watts at about 20m/s is an observation until I can get it to fly around 15m/s. Time will tell but I may have to try some different props. My complete flight with hovers on either end of the forward flight was 14 minutes long and my 21AH pack still read 4.0v/cell.
Cheers!
Hi everyone,
I was reading different power options for this fighter vtol. What do you think of this 6S configuration?
-Front pull cruise motor: Sunnysky Eolo 4125 kv440 and 1612 APC prop.
-Vertical motors: SunnySky V5210 kv300 and 2070 prop.
Payload will be a 400-500g mapping camera. Battery maybe 20A 6S.
Hi Doppler,
It should work ok. The 20" props for the vertical motors may not fit back in the box without some modification, otherwise the power level seems fine.
Good luck!
For this flight, I enabled my air speed sensor and installed my GoPro Hero7 camera with the tilt down gimbal. The plane flew great and the speeds were well controlled by the AS sensor.
For some reason, the lost plane sensor was tripping so I look into that. My only change was to plug in the gimbal tilt servo and power up my video downlink.
I’ll pull the log, post some graphs and discuss my speed findings from 17m/s, 15m/s, and stalls around 10-12m/s. I had two great flights and a fun filled day!
I stand corrected. The stock recommended props for the MFE Fighter 4+1 VTOL are 20x13 for the forward flight motor and 20x7 for the quad motors so your selections should work fine in the box.
Cheers!
