Hello all, new member here and new to 3D printers in general.
I have a P3 steel clone given to me by a friend. I'm not sure which one it is, seems he had bought it from HTA3D in Spain.
The printer uses a RAMPS 1.4 SB Premium from staticboards and DRV8825 stepper drives with Wantai Nema 17 motors.
The Wantai stepper motors are rated at 2.5A and 1.25 Ohm/phase resistance.
I've spent more than a month fiddling with the printer, understanding the connections and Marlin, flashed it with the latest stable version,
and made some improvements, such as getting a Chinese clone of an E3D V6 hotend, adjusting the extruder from direct to bowden, etc.
The printer was badly configured, X axis was reversed (0,0,0) was at the bottom right side, and its accuracy wasn't very good (it would easily miss 1mm or more when printing).
I went through the process of calculating steps per unit for X and Y axis, and now I'm trying to figure out how to do the same for the extruder.
My first problem is that Marlin seems to default to 1/16 microsteps, but the DRV8825 does 1/32 microsteps.
So
first question, what is the formula to adjust accordingly the steps per unit for the extruder?
The extruder has no gears, just an extruder hobbed drive pulley which I haven't measured, but is most likely 5mm diameter.
Furthermore, I have seen videos and posts of people adjusting their POTS on their drives.
I measured the current and voltage of each drive under idle and load, and found it to be:
X axis: 0.7 volt ~ 0.04A @ 5V or 0.03A @ 12V
Y axis: 0.5 volt ~ 0.06A @ 5V or 0.05A @ 12V
Z axis: 1.0 volt ~ 0.14A @ 5V or 0.13A @ 12V
I took readings twice, once by grounding to the 5V pin on RAMPS, and once by grounding on the 12V pin on RAMPS.
Motors where moving when I took the readings (e.g., not idle but under load).
I haven't measured the Extruder yet, because the fan of the hotend isn't working and don't want to risk melting the clamp.
Second question: how do I formulate or calibrate the motors properly?
Empirically by adjusting it as low as possible and then turning it up or is there a specific value(s) I should be aiming for?
Many thanks for anyone who can help!