Creality Ender 3 Issues

Hello everyone. I recently picked up an Ender 3 and I'm having some issues. Mainly, the nozzle keeps hitting/dragging on the print. I replaced the print surface that was included with a glass one due to it bowing up in the center. A glass bed won't do that, will it? Leveled the print bed again, and started a print this evening. After an hour, the nozzle was really hitting the print as well as going to random locations on the print and driving itself into the print (that was a new one). As it got to the back corner, it pretty much decided that it didn't want to print what it was printing and started printing off to the side. This isn't the first time it's done that and I'd like to figure out what's causing it so I can hopefully fix it before it causes damage to the machine. It also doesn't seem to like printing anything over 3 or 4 inches in height. I've included a picture of the failed print so you can see what I'm talking about.



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Did you add anything to it? With the glass bed you might need to make adjustments to your offsets. and adjust your z axis stops. This might help with that a little.

The only thing I've added was the print bed. I'll look into adjusting the stops. It was just weird to see it actually do that. I was just trying to see what the nozzle was scraping across

I just picked up an Ender 3 Pro as well. I noticed when printing thin tall pieces (6") my nozzle will drag across the infill when it's relocating to another side of the print. Z axis hops are very time consuming so I can't get myself to do them. I don't know if this is the same issue you're having but it turns out it's over extruding so the infill is just slightly taller than my nozzle. The biggest problem this causes for me is the plastic buildup on the nozzle from lightly hitting the infill after 20 hours or printing.

Yours is happening right away. If the glass is higher than the original pad that came with it you'll definitely need some bed adjustments. I would check to make sure your step/mm is correct by printing a calibration cube. My Ender came PERFECTLY set up on the Z axis so I haven't had to deal with that issue yet but adjusting the X and Y was required.

That said there are some experimental 3D printer setups where measurement (and possibly closed loop controls) is involved. (E.g. in SCARA robots, both serial or parallel mechanic designs. There it can be hard to implement end-stops. So one can instead try to detect a crash with accelerometers and stop the crashing motion before damage occurs, or just before the unpleasant noise of skipped steps sets in.)