Innovative A4988 G3D Stepper Drivers

Hello,

I bought 5 Nema 17 :

Manufacturer : Wantai
Holding Torque : 4.8 kg/cm
47.1 N-cm
Shaft : 5mm
Voltage rating : 3.1
Stepping angle : 1.8 degrees
Current rating : 2.5A
Nr. of leads : 4 (30 cm)
Type : 42BYGHW811

So I wonder if I can use this stepper motor driver (A4988) for my stepper motor which need 2.5 A ?
It seems that it can`t, but I just want to be certain.

thanks
yrsemoi

Edited 1 time(s). Last edit at 05/31/2013 07:45AM by yrsemoi.

it works !

im glad you got it working and you don't need to run them at 2.5 amp that for running them at max, i have mine at 0.8 amps although not printing but gives room for calibration laters

I am also using the 2.5 amp motors, works fine, they don't get hot, the only thing you need is to actively cool down your stepper drivers with a fan.

Thanks you for your advices

Hello, unfortunately I suppose that something is broken in the electronic, I have a reprap prusa I3, my power supply is 550 W I'have tested the power that it's ok, 12 V on yellow cable, and motors nema17 now I explain you my tests:
I 'have tried the sprinter firmware, the marlin and the ramps 1.4 test.
x-axis and y-axis are working well, I managed to do the calibration, but the z-axis does not work well:
I had to lower the fed rate to 10 because when he returns home the motor is blocked in one turn and doesn't continue, even at low speed is jerky, when the z motors stops you hear a ticking, the z-axis is controlled by two M5 threaded rods, the motors are loosing steps every movement is different in measured distance
On z axis i have put on max the REF, the only way to move the motors, and OSC screw never end

I have also tried to modify the z axis step per unit value, something more then 4000 as reprap calculator suggests

So this is what i did to make z axis work, but is very slow in z homing, I have tried to print but the z-axis lost millimeters

The current is set too high and the chip is going into thermal shutdown which is what is causing the ticking when stationary. Reduce VREF until it runs cool enough to touch.

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[www.hydraraptor.blogspot.com]

Hi again, Nophead,

I followed your advice (backed by the creator of Megatronics, too) and grabbed 4 of these babies. Pretty strong for their size, and fully in line with your advice (low voltage, low impedance, amps per phase within driver range). However, my Megatronics arduino, in conjunction with the DRV8825, seems to drive the newer, low voltage motors, at the exact same max. speed as the other, 12v motors: 400rpm.

I tried everything, I think: full step mode, micro-stepping, constant speed, acceleration, but couldn't squeeze anything above 400rpm out of ANY motor attached to this Megatronics+Pololu combo.

Am I doing something wrong?

Are speeds higher than that actually really achievable with an Arduino + Pololu driver? (I mean: could there be an upper threshold of what is phisically achievable with this combo, due to processor cycles frequency or something like that?)

Another question: the low-voltage-low-impedance motors mentioned above have another odd behaviour: they run OK (full power, not losing steps, quiet) at the higher range of attainable speed (around 300-400rpm), but run poorly at lower speeds (be those speeds constant or just part of the accel. ramping up phase) - meaning that they choke, run with low power, easily lose steps under pressure etc.

One more thing I noticed happens with these low-voltage motors: when the motor is running, the PC power source I'm using for 12V seems to go on overdrive: its fan slows down. Could it be the power source is not strong enough for the 2A/phase the motor sucks up?

Thank you,
Eros

Something strange today, I managed to get my new MendelMax 1.5 working, however, the Z-axis would stall when homing. Moving up is no problem, and moving down was a small problem.

Now, I've set the homing speed of my Z-axis a bit lower, but it wasn't superfast already. Using an M5 rod will ofcourse not make it much faster either, but I am pretty sure that my normal pololu's are way faster and they don't stall.

Now, the power is adjusted correctly, the other trimpot is set to a value in between max and min, I've only trimmed it up enough so that the loud stepping oscillations would be silent.

Tomorrow I will try out to make the whole printer go 200% faster, ofcourse, it will be a bit more noisy, but now it's going mostly between 30 and 50mm/s in all directions which is painfully slow.

Which motor can you advice for an i3 rework?
42BYGHW811
42BYGHW803
17HS3001-20B
Thanks