This is probably a perennial question.
I have a CNC3018, it came from BangGood via Czechia.
The Stepper controller board is totally unmarked (no branding or model numbers etc.).
As are the steppers themselves, though I'm guessing they're some variant of NEMA 17.
The board seems to be made by someone called RATTMMOTOR
All I really need to know is :
1) How can I determine the current rating of the steppers.
2) Can I adjust this driver board to use steppers with more or less current?
Are you able to use the machine?I would suggest you just get on and make some stuff,even if slowly.The machine you have will probably work but you need to understand that it functions as a whole and has probably been designed so that the entire assembly is fairly balanced in it's ability to function.It won't tear through 25mm ply in one pass.Which you may not have intended to so anyway.That board should be sending signals to a power supply and telling it when to send pulses to those NEMA 17's.There ought to be a plate on the power supply indicating how much current it sends and at what voltage.
They're most likely 1.7A. I have one of these as well but I immediately upgraded the steppers to 92 oz/in motors and DRV8825 drivers so I don't have much advice in the way of adjusting the A4988 drivers other than the attached images. There's a calculation for doing this and it's not really hard to do. The motors I replace mine with are 2.1A so I added bigger heatsinks, active cooling, and adjusted the drivers to approximately 2A.