Quadplane Land Transition Issue

Can anyone help me out with this issue I am having. The take offs are looking great, but the land transition I can not get the front motors to activate causing it to land hard. Idk how but I somehow manage to land onetime with three motors. It hit hard, but it still landed. The last flight both front motors did not engage. I am flying with Castle ESCs for the quad portion. Anyone else have had issues with Castle ESC on a multi rotor?

I have a hex and while having Sunnysky 580 motors, I was using the castle MultiRotor ESCs. They performed flawlessly until I changed to 380 motors and then the problems started. I’m guessing that Castle Multis cannot retard their timing far enough to handle lower KV motors. I struggled to get them to work. I came to the conclusion that since Castle was fairly new entering into the multi rotor market, that they were almost beta hardware. I switched to Hobbywing xrotors and they have performed flawlessly.

I know Castle makes good electronics, specifically for land and water based RC vehicles. I don’t think their MR solutions are quite ready for prime-time however. They seem to be hit/miss based on the motor you use.

Sorry I’m not sure what is happening but I noticed your motors leave the props pointing forward, which is great to reduce drag. Is this intentional and if yes how?

While I can’t help with the ESC issue, I can confirm that Quadplanes can land with failed motors. The Quadplane just needs enough airspeed to keep the control surfaces in control. If you look at the logs, your ailerons and elevator/rudder will have large deflections. The landing was hard since no more lift could be produced without unstablising the aircraft.

For a given ARSPD_FBW_MIN, does the code use ARSP.Airspeed or GPS.Spd to determine when to transition? Does it use the former if ARSPD_USE is 1, otherwise the later?

It uses airspeed. If airspeed sensor is not available then I am not sure. I guess it uses the estimated airspeed.

Where can the “estimated airspeed” be found in the logs? I’d like to be able to graph it.

EDIT: I’m asking because I see my airspeed super unstable compared to GPS, as can be seen below. Is this expected? Wind was fairly steady and light.

Sorry for the super late reply. I am barely on here. But yes it is on purpose. It is a setup used that the company I worked for develop.

Btw my plane ended up crashing… For some reason right after transition finished it pitched full 90 degree up. Nothing in the logs show the front two motors turning or the elevator throw was not that great.

Kevin, sorry for your loss. Can you confirm what firmware version you are running?

Have you seen this post: Help with anomaly on VTOL plane transition

Looks like he had the same issue after he did an upgrade to 3.7.

Jacques

I believe it was 3.7 also…

Btw my plane ended up crashing… For some reason right after transition
finished it pitched full 90 degree up. Nothing in the logs show the front
two motors turning or the elevator throw was not that great.

https://www.youtube.com/embed/Zd5SVgeUeX4?feature=oembed

Ouch!

Please provide dataflash logs!

crash.tlog.stl (1.3 MB)

Sorry I have not uploaded the log. But here it is. I am about to go at it for a second time.

EDIT. Edit the extension name. Not sure why it went to a STL.