QuadifyRC 124016 124017 EAT14 cogging issue fix
The WL Toys 124016 and 124017 (and the Eachine EAT14) have a major issue with cogging - the stuttering that occurs when accelerating from standstill or low speed and is a major downside to these recent releases. Cogging in your car is not by bad luck but by design choice; in the search for top speed bragging rights, the tall gearing has really compromised these cars ability to accelerate. Never fear, QuadifyRC to the rescue! I'll give you 3 and a bit options on how to fix this issue by addressing the root cause rather than by going on a wild goose chase and addressing the wrong things.
Cogging - The Root Cause
As soon as I found out WL Toys and Eachine had retained the big 27t pinion from the brushed models I knew they would be fast but were going to be poor on acceleration. This turned out to be correct as you can see on my Eachine EAT14 review which has the same running gear as the 124016 and 124017. You can get away with this big pinion on a brushed motor (like with the 144001, 124018 and 124019) because of the way they work but not on a brushless motor because of the way they differ mechanically. Cogging is when the electromagnetic field invoked by the motor is not strong enough for the motor rotate and catch the next pole thereby getting out of phase and rocking back and forth; it's that jiggle your car make before it takes off. So what causes it? The motor can not generate enough torque for the given load. The 2845 is not a small motor for a car this size so it is safe to assume that it is the load that is unreasonably high due the very tall (fast) gearing.
Since we know the root cause we need to address it directly in order to get the best quality solution but before I do that I'll let you know the things that will NOT fix it: