Scorpion Motor - Buck Rogers Mode

[Planehazza]

Hi all,

Got a used motor, a scorpion HK4025-1100, but when I apply power, either through increasing the throttle or flicking out of hold into a flat line 60% 'curve' (Kontronik Kolibri ESC) I get a stuttering which reminds me of the robot from Buck Rogers! It's like it's stalling and eventually getting 'in sync' before starting...


Video: https://photos.app.goo.gl/t4x3Hh2Zj3xNowFZ7

Given the sounds, I have a few things in mind:

• Timing could be out? Given it's quite an old motor, perhaps the Kontronik is a little too aggressive for it out of the box?
• Belt tension. It's a Kraken, so the belts are tight, but not shaft bending tight.
• Kolibri is set for Mode 4 Heli, Mode 8-3 Telemetry-Futaba, Mode 10 for 7.4v BEC. I can't change timings etc without a ProgUnit.

Anything else worth looking at?

Thanks!

[Grumpy]

If the 'start up power' is adjustable you could try that. As the motor does start then it's not doing any real harm. I dont think timing will help because the juddering is the ESC sending pulses to move the motor so that the ESC can sense rotor position (on our sensor-less motors rotor position is only detectable once the rotor moves past the magnets). Only when the ESC can sense the rotor position does timing actually make any difference.

[trillian]

Check the motor and battery wires for any possibility of a less than perfect connection or a potential short. The Kontronik ESCs generally just work without any fiddling. I was running a 4025-650 with a Jive 100 and it worked just fine.

[Made2Fade]

Low timing or KSA mode as it used to be on the Jives... plus go up one on the startup power. Well known issue on some scorpions and most Hacker motors