Geeetech prusa i3 pro B quality issues

[Roxy]

Hello,
I have a prusa i3 pro b from geeetech. I have some quality problems with it.

You sound surprised! I have a very low opinion of Geeetech quality.

With that said... Those prints are not that bad. It looks to me like it is under extruding at times. It could be an occasionally plugged nozzle. But I think it is more likely the extruder stepper motor is under powered. (Geeetech does put low torque stepper motors on the printers I've seen.) Can you turn the power up to the stepper motor?

One test to confirm this theory is try printing that same object but with the nozzle temperature 10 degrees higher. The print will look bad. But if you aren't seen 'under extrusion' it is because at the higher temperature, the filament is easy to push through the nozzle.

[organotis]

You sound surprised! I have a very low opinion of Geeetech quality.

With that said... Those prints are not that bad. It looks to me like it is under extruding at times. It could be an occasionally plugged nozzle. But I think it is more likely the extruder stepper motor is under powered. (Geeetech does put low torque stepper motors on the printers I've seen.) Can you turn the power up to the stepper motor?

One test to confirm this theory is try printing that same object but with the nozzle temperature 10 degrees higher. The print will look bad. But if you aren't seen 'under extrusion' it is because at the higher temperature, the filament is easy to push through the nozzle.

Before 2 years when I bought this printer after assembly and first calibration I measured with multimeter what is the actual voltage on those stepper motor controllers and find out what the voltage was fine. I have not checked after that what can be the voltage. I can actually measure now and let you know.

[organotis]

I did measure the Vref fort the A4988 made by Geeetech. The Vref must be within 0.8V-1.2V. In my case the Vref was 0.9V on all 4 stepper controllers. I did raise the voltage to 1V and try to print something someday this week.

[Roxy]

The Vref must be within 0.8V-1.2V. In my case the Vref was 0.9V on all 4 stepper controllers. I did raise the voltage to 1V and try to print something someday this week.

I pretty much have all of my stepper motor drivers putting out the max current. The stepper motors get hot enough it is uncomfortable to hold your hand on them for 30 seconds. But I have not killed a stepper motor yet doing that.