Solved Print Head only moves one direction on the Z axis

Just set up my ROBO 3D R1+ last night. Was all excited this morning to try printing after reading the manual before bed and watching the video this morning. Unfortunately, when I try to print the calibration circle STL, my print head only moves further from the build plate when it glides along the X/Y plane. When I use MatterControl and try to home the head, it seems to correctly move to (0, 0) on the X/Y plane, but then it raises up 1-2 cm on the Z axis every time I click Home All. If I release the motors, manually twist the control rods so the nozzle is almost touching the build plate, and then start a print job the printer goes through the 9-point self-leveling but after each point the head lifts 1-2 cm and never lowers back down.

I've tried printing the calibration circle both with and without "Printer has self-leveling" option turned on. I've tried powering off the printer, rebooting my computer, and turning everything back on. I've tried reading the "My ROBO doesn't auto-level correctly FAQ" but I can't understand parts of it and what I do understand doesn't sound quite like what I'm seeing. I've looked at the control motors on the z-axis control rods and both sides have two leads to them, so that wild guess I made doesn't seem helpful. I've even looked at the printer carefully again to make sure I didn't leave any packing material in place.

Am I missing something super-simple? I expected printing the calibration circle to be a little more plug-and-play than it has so far turned out to be. I can go back to the manual more deeply, but a brief review of it this morning didn't have anything that leaped out as meaningful. I've tried to do some real troubleshooting before creating my thread, but I'm so new and underinformed on 3D Printing that I don't have a lot on knowledge to work with. Please give me suggestions for what else I can check, as I'm really excited to be entering the 3D printing world, but completely at a loss as to how to move further in to it.

Thanks in advance!

 

Thank you for the suggestion. Searching for ROBO z-level switch based on your comment lead me to Novice Expert's leveling troubleshooting video on YouTube. After watching that, I looked at my ROBO and found that the right side of my R1+ isn't lowering enough to press the auto-leveling switch. I'm working on that - I can get it down closer (It was about 2 cm away before), but can't get it all the way to the switch. Still trying to figure out why the print-head mechanism isn't lowering enough to hit that switch. But I think if I can figure out how to get the switch compressing correctly, things will probably work. Still not certain this resolves my issue, but I'm feeling confident. Too bad I have to leave the house in a couple of minutes to taxi the kids around - will be a couple hours before I get to focus on this again and find out if it works correctly.

 

That was it. Still need to level the mechanism so things print right, but once I got the mechanism sitting on top of the right Z-axis switch right, everything started working. Now to figure out how to mark my thread resolved. Appreciate the quick solution!