I gave this product 2 stars because it is very difficult (in my opinion) to tell if you are calibrating it correctly. I've been in this hobby since 2003 and so I'm not new to calibrating ESCs. However, this ESC (due to the lack of info and applying incorrect info to calibrate it) I believe has cost me over $200 in damages to my T45. I had to replace my fuselage and wing set as well as some servos and misc pieces as I had to deal with a plane that did not have sufficient thrust and I crashed trying to land her. In fact, I am still repairing her from a second outing when I thought I had it calibrated. This ESC has caused me heartache until I could figure this out. I called MotionRC for support but they did not have these in stock and could not test it themselves to see how these ESCs actually work and their beeping sequences. After some troubleshooting, it was suggested that I try resetting the ESC to defaults and see if that made a difference. It did not because it turned out the ESC was working correctly to begin with. We (MotionRC and I) did not have the correct info to confirm if it was behaving correctly.
Although MotionRC documents how to calibrate the throttle on the vast majority of the models it sells (https://www.motionrc.com/blogs/motion-rc-blog/my-controls-work-but-why-doesnt-the-motor-power-up), these HV ESCs from Hobbywing (that are components in the Freewing 8S 90mm jets) are different.
Here is the Hobbywing ESC manual: www.hobbywing.com/products/enpdf/FlyfunHV.pdf
Here is a video I made to demonstrate how to reset the ESC to defaults, calibrate the throttle and run through a normal startup procedure:
https://youtu.be/SIo8ovUqpno
