Solved Z-offset keeps changing

Hello,

I since been printing stuff successfully, but occasionally the z-offset will change after a print completes. I have to then re-find it (a different number) and enter the new one into the g-code. I'm not quite sure why this is happening, and it's getting fairly frustrating. The new offset keeps resulting in it dragging up some glue into the nozzle and I have to unclog in addition to adjusting the offset.

Any ideas? It tends to oscillate between .49-.6mm

Thanks,

 

Do a paper leveling and make sure your Z switches are pressed solidly up against the idler but not supporting it.

 

Your hotend must be loose or something. Once you find the offset you shouldn't have to change it again unless you change hotends, rotate your hotend or something along those lines.

 

Sorry for the late reply.

I've been paper leveling it, with the same results. So, if it's my hot end being loose... what do I do? How do I check that and fix it?

Thanks,

 

kinda push on the hot end and see if it wiggles

 

No, it's pretty solid. The mount jiggles a bit, but the hot end is firmly seated.

 

This is ridiculous. Nothings even consitent anymore. At -.48 offset it was dropping plastic at almost 1mm above the plate, so I put it to -.485 and it was dragging on glass. Just to check, I put it back to -.48 and it was now dragging on the glass. I'm now at -.46 and it's still dragging on the glass.

Keep in mind the original offset that worked was -.57

 

My printer is now starting to make some rather alarming, and loud, sounds when it moves in the z-axis. The threaded rods are starting to screech and sound and look as if they're wobbling way too much, and are about to come out.

 

pics or vids of your issue will help us a lot

 

Also if you are at -.48 and you need the nozzle to be higher you go more negative. So in order to raise the nozzle you would do something like -.6

 

There are a few questions asked every day by various people. Most questions have been answered,...

For starters, printing in the air above the bed is likely to be a result of an unlevel bed. Watch your z switches during the autolevel process and you'll see.

 

Alright, I've taken a video... stand by while I upload it to Youtube

 

Wait a minute... Decreasing the offset from .5 to .4 in the negative should be it lowers less. At least that's what I thought.

I'll try going back up. But the sounds are still rather alarming, and oiling it hasn't helped.

And the bed is level. I've checked that, and messed with the rods until I heard a click for both as well.

 

Alright. Here's the video. It's a little shakey. I was in the middle school classroom, so you hear me prepping them because a kid is terrified of loud noises...

Anyways. The sound it makes at the last row of leveling is what's alarming me.

 

I understand now... but in my mind a negative offset would be it's going down. So more negative means lower, from some zero above the bed, and more positive would be higher above that zero. So, now I know otherwise. I'll give you an update on that later today, since I have to go into classrooms for a while.

 

A few things. It looks like your left threaded rod is loose in the coupler. Tighten the 2 set screws on the coupler. Another thing. If you don't see filament getting put down on the bed stop it right away or else you will get a jam/clog if you don't have one already.

 

I've been stopping it once I see it isn't printing anything... I just let it run a little longer so you guys could see it. However, I've become quite adept at unclogging/unjamming this thing. I'll hunt down a <strike>screw driver</strike> allen wrench that fits, and get that tightened, and try moving my offset back up and I'll update.

 

Thank God, okay. We're good. Thanks for all your help, guys.