mini kossel x/yaxis shift

Hi,

After installing the hotbed, i have this weird issue: after printing the first 3-4 layers, the hotend starts to shift the filament on x/y axis. (see the attached pictures)
The first layer looks ok. I am keeping the hotbed temp at aprox 70C and PLA temp at 200C
The printer is Arduino Mega 2560/RAMPS 1.4 with DRV8825 drivers

I suspect that there's an issue with the current within the motors, because i hear a noise when the shifting occurs.

As you said, it's probably a problem with the motor current, assuming the carriages all slide freely. If the motors and drivers are running cool, increase the current a little. If either the motors or the drivers are running hot (in the case of the drivers, too hot to touch for more than a second), reduce it.

---

Large delta printer [miscsolutions.wordpress.com], E3D tool changer, Robotdigg SCARA printer, Crane Quad and Ormerod

Disclosure: I design Duet electronics and work on RepRapFirmware, [duet3d.com].

1. Using a multimeter, adjust the Vref on the DRV8825 stepper drivers until you get approximately 1.4A peak current (1A RMS).That usually means 0.7V measured on the trimpot for DRV8825's. Detailed instructions and pictures are in the wiki: [reprap.org]

2. What PSU are you using? Again using a multimeter, check the voltage supplied by the PSU to the RAMPS when the heatbed is heating. If the voltage supplied to the RAMPS drops by more than 1.5V, check your wiring and check the voltage at the PSU. Either use thicker gauge cables or change the PSU.

Edited 1 time(s). Last edit at 04/06/2015 07:03AM by AndrewBCN.

The voltage difference was pretty big when heating the heatbed, more than 1.5V. I suspect because the PSU adapter ( i didn't want to trash the connector ) was using small gauge wires.
Last night i re-purposed a computer power source (250W) and tonight i will test.

It seems all good now!

The power source looks good, i may have to get a better one but... until now all is good !