We are building a vtol tricopter vectored yaw quadplane. And two thing we cannot understand about last fly. First thing is plane draws circles in the air in QLOİTER mode and drifting in QHOVER. İs it possible because of to much front tilt motor angles? Because our past fly tests we do not get this type of behavior and we changed it’s angle because it was bending the wing. And second thing we were trying to tuning Mirzam01 in this flight, then we apply Tuning Process Instructions — Plane documentation / PID Controller Initial Setup then try to AUTOTUNE . Then we crashed .
At the time point in marked with an A, the left-hand motor suddenly fails.
You can see how Arduplane regulates motor 2 to saturation (2000 µS), at the same time the current consumption suddenly becomes much lower. Motor fault or ESC or a cable defect is a possible cause.
I experienced a circular flight pattern, also known as the “toilet bowl effect,” with my VTBird VTOL and several other multicopters. You can find examples of this on YouTube.
This issue arises because changes in your location affect the Earth’s magnetic field. To fix this, you need to recalibrate the compass after you move the location.
Make sure to read the documentation and recalibrate the compass after securing a good number of GPS satellites.
This problem is unrelated to the PID control system.
Additionally, slight drift in QHover mode is normal.
I recommend starting with a regular quadcopter before trying VTOLs. VTOLs are very dangerous and require quick reactions in emergency situations.
Thank you for your lifesaving suggestion @Rolf ! When we see your message we were just before a fly test again and then we gave up on test. And made inquiry to motor , ESC , power way triple. We change all power wirings, we changed left ESC and made a motor test . The issue from power wiring and left motor. Wiring has a conduction problem maybe from soldering at left wing part of cable , and motors shaft clip was loose , our rotor came out of the stator a little bit but not completely separated. We fixed everything and everything looked nice.
To fix drawing circles behavior in QLOiTER mode (we had to use another gps after left motor crash because our gps damaged) we calibrated gps and it worked. Thank you for your advice @Truth_T .
But unfortunately we crashed again. İnitial investigations determined that the problem was in the power line ,caused by connector XT150 between battery and PDB. The connector seemed non-conductive but after we pluged in the battery to PDB and remove it then connector became conductive.
For additional , on August 27th we had a plane crash. Similar to the last flight, on 27 August the power on our plane spontaneously cut out. İt is interesting that the power cut out at landing stage not at the flying stage. So we waits for yours advices.
Log file and flying video: https://drive.google.com/drive/folders/173zWz3wvnBH-Yt9qmuTGx3B2HeKUxOOe?usp=sharing
I’m glad I could provide some helpful information.
Just to clarify, it’s important to remember that what you calibrate in Mission Planner is the compass, not the GPS. This is a common point of confusion for beginners, so I wanted to highlight that distinction.
I would also recommend starting with a small ArduCopter. It’s safer and more manageable for beginners, especially when you’re still learning how to calibrate and control the system.
Flying with misunderstandings can be dangerous, and I noticed a few misconceptions in your post. However, it’s ultimately your decision. Just be sure to prioritize safety.
