On Test Flight 4, once the AS sensor was enabled, I was able to fly in LOITER and CRUISE modes with proper autonomous throttle control. When testing the stall speed, the left wing started to dip and then the Q_ASSIST_SPEED kicked on around 9m/s.
Although not quite the same scale, you can see the ARSP.Airspeed graph has minor variations.
On the stall, I had the throttle at minimum, and the air speed was about 10m/s which is exactly what the MFE specification says. I may leave my settings like this for a while as the Q_ASSIST_SPEED kicked in at 9m/s when the left wing dropped.
MFE specs the suggested flight speed to be 17-20m/s. My speed during LOITER mode was 19m/s at mid-throttle. Even though the speed was a bit lower (20 vs. 19) than my previous flight, the forward flight power level was a bit higher at 414 watts. I’m not sure why the readings were different but may be within the measurement tolerance of the logs.
I think my system is running ok so I’ll leave it alone for a few flights and see how I like it. When the wing dips on a stall, the Q_ASSIST_SPEED kicks in around 9 m/s so it feels safe to me.
I installed two lost plane buzzers and it was the Hobby King cheapo version that started failing so I removed it. The better ViFinder version from Aloft Hobbies with the battery back-up still works fine. It is a better solution since it can still work if the main flight pack disconnects upon a crash. I increased the LiPo cell size so the buzzer can work for a full day now. 00000010.BIN.param (20.7 KB)
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My buddy captured my MFE Fighter hovering from the air during take-offs. There was some wind, so in QLOITER mode, the forward motor was kicking in to help hold position. My Q_VFWD_GAIN is set to 0.05. I noticed that it made the plane rock a bit whenever the forward motor turned on or off so I decided to try setting the gain to 0.0 and see how the plane holds position in wind. When turned sideways to the wind, it has a nice steady lean into the wind, which is what I am used to in my copters.
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It looks like the MFE Fighter 4+1 finally made it to the Banggood USA warehouse. I see 10 in stock.
At 1:22, the noise was the quad rotors coming on as heard through the on-board GoPro H7 camera. I had just switched from a forward flight mode to QSTABILIZE mode before the turn.
I had a few more good flights with my MFE Fighter VTOL. I preferred my new Q_VFWD_GAIN setting of 0.0 since it no longer rocked the plane and still held QLOITER position in 10-15mph wind. The Lobot PTZ tilt gimbal is working great and I have a solid 5.8GHz video downlink to my monitors and goggles. Overall, I am very happy with the Fighter 4+1 performance!
I have a PNP version ariving today. Aparently it has new optimised motors, custom built for this rig. I will post details when it arives.
From the videos, there looks to be a nice power distribution board and Cube carrier. I don’t beleave this is included in the PNP. No mention of it anywhere.
Did you get that from AliExpress, and if so, which seller? Everything I saw had outrageous shipping costs and as you might have seen in this thread a lot of people had trouble getting the parts shipped to them for the PNP version.
Hello, I also want to buy a fighter but I have not found a way to make the shipment cost me less than the plane, I am in Latin America, I thought I would buy the frame in bangood and bring it to my country by locker and then if I buy the rest accessories from China
Thanks to a post by @GregCovey in a different thread, I learned Banggood sometimes carries this VTOL in their USA warehouse. I just ordered one myself. I think there are a few more.
Thanks to everyone who provided so much great information in this thread.
Hello!
My name is Richi and I come from Austria… Iuckily I got the only mfe fighter from banggood Czeck warehouse! At the moment I build this bird. Thanks for all the information in this forum - it helped me a lot building the plane.
Here’s my solution for installing the esc for 6s setup.
Hi all, I have my airframe built now and settig up the Cube tomorrow. I note mention of MFE proviging a set of get you goung QPlane perramiters, are these the ones on Github? here
Has anybody flown this with 12s, 22,000mah setup?
MFE’s sugested max battery12s 22,000, some lump of battery and I am hesitent on trying it.
thanks
Yes, that is the correct link to the parameters and they work with normal APM Plane releases.
Since your testing flights will likely be shorter, you could use a combination of a lower capacity 12s battery and some weight. I use a 6s 21AH battery and have never flown long enough to use the entire pack. I suspect a flight time approaching 30-40 minutes. The important part here is to maintain proper CofG balance.
Also, consider adding weight for your payload on the initial test flights. It is best is you can simulate the final flying weight during the testing phase.
Word of WARNING for ANY motor / bullet connectors.
Unfortunately, the PNP version’s motors come with the notorious leaf spring style bullet connectors.
I would NEVER recommend them to be used on ANY aircraft, they are a crash waiting to happen.
Fortunately, I was bench testing the system, when one of the VTOL motors started to appear to lose sync, untill, it finally stalled.
There is nothing wrong with the motor or the ESC. Looking at the bullet connector, from the ENHANCED, attached image, with the enhancement, you can see green corrosion at the top and bottom of the outer leaf spring, causing bad contact to the main body. These style connectors are notorious for this. It is clear what would have happened during VTOL flight. NEVER USE THEM.
With the well-fitting ESC supplies with the PNP, there is not need for connectors. Use them to get setup (motor direction) mark them off and solder the motors direct to the ESCs.
Interesting first trials today. Running on 12s, 22,000 giving an AUW of 8kg.
Q initial peramiters I downloaded caused crazy oscolations, twisting the wings considerably. Ended up almost halving all the PIDs in pitch. Hovers well and respincive.
Now, transitioning into forwards flight was ieresting. Got upto about 20ms when Q motors stopped. Then it instntly stalled in FBWA at 20ms, throttle responce was hindred, limated to 75% as per downloaded perams. Hit QLoiter and all good, save landing.
Some testing later, facing into 4ms wind found that 75% is not getting beond stall, need 85% to reach 21 to 22 ms.
I would say this motor / prop combo from the PNP Kit is well underpowered, when wind speeds hit 6ms needed 100% just to prevent stalling.
No idea what power the motor is, but it is a 120kv with a 20".
I would check your Q_ASSIST_SPEED setting and make it just below your stall speed. The original setting was 12m/s. My lighter 6s setup uses 9m/s.
This is confusing to me. The original 12s forward flight motor was the 5015 210kv with a 20x13 prop. A motor with only 120kv will not spin fast enough.
Hi Greg, I will double check the KV as I may have read the wrong packaging, there is nothing written on the motor. I suspect you are correct and the VTOL motors are 12kv, not the forwards thrust.
The Q_ASSIST_SPEED from the downloaded perams was 0 so setting it to 15 for now and I will test and gradualy reduce it as i am testing.
Experiments last night I found little power in the thrust below 1500ms and starts to kick in from 1700ms ish. As transitioning from mid stick “1500” from QLoiter to FBWA sets the thrust motor to 1500, I am thinkink i may set servo3-trim to beond 1500.
Now I am confused, looking at servo3-trim as I type, is it set to 1100!
