My Atomstack A5 M50 PRO makes a “knocking” sound immediately after being switched on. With the same frequency as this knocking sound, a red and a blue LED on the motherboard are flashing. This sound only stops when I disconnect both stepper motors. I see exactly the same behavior even when using a…

Atomstack A5 M50 PRO starts 'knocking' when powered on

MikeyH (Mike Hembrey) March 7, 2026, 7:01pm 11

You get Amazon there? Buy the ESP32 v1 from Amazon and use the links in this thread for the software. You get air Assist capability as a bonus.