Worked one time.

I just put together a Hesine 3D printer. It is marketed under the name Omni M-505. But comparisons show it to be a Hesine 505. I bought it because it was cheap($235), but I have since heard about deals where it is being sold for $70.

Anyway, I printed out the test gcode that came with the printer, and realized that I needed to slow the print speed and temperature down for PLA. But that is where I started running into an issue where the print bed is trying to move the bed backwards when the bed should be moving forward. The controls move the bed in the proper direction. The problem only occurs when I try to print an object. With the bed in "Home" position and against the endstop, it tries to move it further back instead of moving it forward, and filament starts running off the front of the bed.

Using the Cura software, and I actually pulled the profile off of the supplied gcode file. I have also gone down the item by item profile list to adjust everything according to specs, which has not helped. I have also gone over my wiring looking for problems. No obvious problems there either. This printer has a Melzi board. It also only has a 15 amp power supply. I have a 30 power supply sitting here if I need to replace the original one. But this problem has me confused. It seems to be ignoring the endstop at the back of the printer when it starts to print. Yet it acts properly when I home the bed.

I'm confused and stumped. Any ideas?

I suspect your confused

The software control’s are related to movement of the print head

Thus if you tell the head to move forward, since the head can't move in that direction, the bed moves back
and if you move the head back, the bed moves forward.

So I suspect you have your direction of movement for Y backwards.

is your stepper motor plugged in backward?

The problems revolve around the stepper motors. I swapped out the 15 amp power supply for a 30 amp power supply. That helped the Y-Axis stepper motor for the bed. I realized that it had been skipping steps. But after getting that one working, I found one of the Z-Axis stepper motors was not turning properly. One Z-Axis motor is not keeping up with the other and is also skipping steps. The wires for both Z-Axis stepper motors are spliced together into a single connection on the Melzi board so each Z-Axis stepper motor is receiving the same power and same instructions. And there is no power adjustments on the Melzi circuit board for the stepper motors.

I just ordered a couple of new stepper motors. If the new motors don't work, I'll throw an Ardunio board on it.

Thanks,
Lloyd Hayes

Edited 1 time(s). Last edit at 01/31/2016 08:59PM by Traveler_Lloyd.

Update. After replacing the 15 amp power supply with a 30 amp power supply, 2 of the stepper motors, the right tension side of the x-axis, designing-building an entirely new z-axis endstop mount, and an updated the hotend air supply, I finally got this printer acting like a normal printer.

In another thread I have some tweaking issues with this printer.