If the motors spinning reserved, you could change the spinning direction in the BLHeli Configuration (Chrome APP). As show below. Do not forget to power the board via battery, so that the BLHeli Configuration could contact with the ESC.
When you are building the 1S brushless drone, the motors would not spin up properly. This is a common issue for many pilots. Here is the description of some pilots about this issue.
While the quad does run just fine, fairly regularly on start up the front right motor doesn't spin, and I can hear the motor restart ( goes through the start up noise) and then If I manually turn the motor once or twice, the motor starts right up after that and doesn't heat up at more than any of the other motors.
I have the new brushless FC. I can power up,and get the motor tones, but if I arm and spin up the motors they just twitch a bit, they never spin up properly.
We think this is normal that the motors could not spin up immediately when throttle up. It is caused by the limitted current on a 1S BLHeli ESC. So when you manual turn the motor to another position, it could start to spinning. Also, there are some advanced settings that could reduce this issue asap.
In the BLHeli Configuration, increase the Startup Power to 0.75 or 1.00. The default value is 0.5.
Startup power can be set to relative values from 0.031 to 1.5. This is the maximum power that is allowed during startup. Actual applied power depends on throttle input, and can be lower, but the minimum level is a quarter of the maximum level.
Startup power also affects bidirectional operation, as the parameter is used to limit the power applied during direction reversal. For low rpms, the maximum power to the motor is limited, in order to facilitate detection of low BEMF voltages. The maximum power allowed can be set via the startup power parameter. A lower startup power parameter will give lower maximum power for low rpms (this is implemented from rev16.1).
--- from "Operation manual for BLHeli_S SiLabs Rev16.x" manual.
Stuck or Damaged
The 0603 or 0703 motors would be damaged after crashes and could not be spin up totally. It usually have the several issue.
1) Stuck and harder to turn by hand;
2) The ring at the bottom of the motor is missing;
3) Motor bells fly off;
In general, if the motor is not badly damaged, it's not hard to fix it. You can remediate it by using the following methods. Please contact us to get vulnerable parts of motor in free. (email: email@example.com )
Here is a video by Cyril for the motor repair details.
For the upgraded version motors (0603 or 0703), the bottom ring and shaft are welding together via laser. It solved the issue that the motor bell flying out completely.