One axis running backwards

I have completed my MendelMax 1.5 build. The X axis homes to the far left of the printer, the Z homes to within 1 mm of the glass, Y homes all the way to the rear of the printer. That part is good. Now, when I try to manually move the printer bed by using the jog controls in Pronterface, the bed runs in the opposite direction of what it is supposed to. If I press 100mm to come towards the front of the printer, it goes to the rear of the printer. This is the only axis that is backwards. It is plugged into the ramps correctly. I just do not get it. So consequently, when I try to print the bed goes in the opposite direction to start the print, it comes forward when it should go backward to go to the center of the bed. PLEASE HELP!!!

Milt

I maybe over simplifying things here but cant you just rotate the connector to the stepper 180 for that axis

If you're running Marlin firmware then you need to change a setting in the Configuration.h file.

#define INVERT_Y_DIR true

Either change the true to a false or a false to a true. Basically you need to toggle whatever setting you currently have.

Or yes, just turn the plug around.

---

---

PrintB.it

The waldom/molex connectors are keyed aren't they? So technically, you have to re-position the pins, not just flip the connector, right?

They are keyed but only with a tab of plastic. It all depends on whether people know how to change and upload the firmware to their boards. It's best to change the firmware but you also have the option of snipping off the tab off the connector on the board and flipping the plug around. Not advised, but possible.

---

---

PrintB.it

I agree. Change in the firmware would be far easier. I was just getting a little pedantic about "reversing the connector", since I hate when people defeat connector keys

Thanks all. But when I turn the connector around, the heater bed now homes all the way forward so the printhead is at the rear of the bed. The jog keys now work correctly but the bed runs in the wrong direction.

Milt

Ah, it may be that everything was working fine.

Don't think of it as moving the bed back and forth but that the nozzle is relatively going back and forth over the bed.

So when you press +Y the bed should move towards the front of the printer but you're moving the nozzle away from you (relatively speaking).

---

---

PrintB.it