any reason why my z-axis will only go up, not down?

any reason why my z-axis will only go up, not down? I2 with Repetier host/firmware.

Based on my usage with Repetier and my delta printer, it seems to only go down as far as it can deem “safe”. This depends on where you set to be home, which if you have your endstops set to max like I do, means it won’t go any farther. Try lowering it as far down as it will go and set the home again. Good luck!

Possibly your z end-stop is permanently on. Try swapping it with an x/y end-stop on your electronics and see if it’ll go down then.

@Tim_Rastall I thought about that actually, but I am not sure how to test that. the light on the led is on.

And my endstops are set to min. I also have to move the z-axis back down by hand, which im tired of doing haha.

Does it go down if you hit “Home Z”? It’s normal for it to soft-limit you to not going into negative Z except for homing. You could also try using M92 to set your current position to something higher, so that it doesn’t think that it’s as low as it can go when you start up.

No it does not. In fact, when I hit “Home Z” it just goes higher every single time. Whenever I hit Set Home, it never remembers where I set it. It just moves the x, y, and z axis about 5mm each time and always in the same direction.

Its strange, and I have no idea why its acting like that.

Does Z just go up a little (say, 1-5mm) when you hit home Z, or does it move up continuously until the enstop is triggered?

1-5mm at a time

Sounds like you have a buggered z endstop. I had the same issue with my i2 I put a 10k pull-up from NC to + and it started to register but was all in all a bad endstop, replacing it fixed my issues.

If the z endstop is bad the z axis has no idea how far it’s aloud to go down, so it will go up instead as to not damage the hot end or the build platform.

Or on the other hand your z endstop could be getting cross talk and or just registering prematurely and allowing your z axis to home at its current position, witch in turn just keeps going up.

And if you are using Repetier host make sure your printer dimensions are the same In the software as they are in the firmware as this will cause issues as well.

Agreed, definitely a bad endstop. Either it’s a short or a loose wire (open circuit) depending on your configuration, or it could just be that you have the inverting option set wrong in your firmware. Whatever it is, the machine constantly thinks that the Z endstop is already triggered, so it won’t move any further in that direction.

So, the way you confirm if it’s hardware or firmware is by swapping with another known-good endstop to see if the behavior changes. I’d suggest you locate where your left x endstop is connected to your RAMPS board, disconnect it and swap it with your Z endstop. Then, making sure the hot end is a few inches above the bed, use the manual controls to lower the hotend by a few mm. Don’t home the Z as (if it does go down) there will be no endstop trigger to prevent it from driving the hot-end into the build surface until you pull the plug :). If this doesn’t work - probably time to check the firmware.

I did find that the end stops were plugged into the wrong spot. (I bought this off of someone and it was broken and Im trying to figure it out still).

However, I played with the firmware for a bit and I did find a solution that worked for the time being.

from true to false

that seemed to give me manual control at least.

That will probably create more problems than it solves, you are now operating without an endstop on Z, and the Z axis has enough mechanical advantage to break things if the controller doesn’t know to stop it.

Yep my mirror platform has a nice crack running all the way through it from the other night. Dono what happened, either hot end crashed or it snagged a part while printing (abs juice is tight stuff sometimes).

Just make sure on the ramps if memory serves right the stops go, Xmin,Xmax,Ymin,Ymax,Zmin,Zmax trace the wires NC from the switch if using just a mechanical switch as an endstop (why use anything else?) to the ramps board NC should be the first wire from the top connected to the ramps, then com, then 10k pull up from NC to +

definitely an improperly installed endstop. Mine did the same when i first tested the electronics. You also cant turn the extruder motor till its warmed up. Check the wiring , if you have a switch on try closing it with your finger and see if you can make it move. If so you just have is soldered to the wrong set of terminals . One is no one is nc , the other completes the pair. You basically want to connect blue and black, and dont connect the midle leg on the switch. (for stock settings) you seem to have reversed it in sw.