Solved Z Axis WAYYYY off after hot end replacement

Replaced my hot end, excited to print, start the print, and the end is about 2 inches above the glass. Even if calibration information was easy to find, and perform, I'm guessing there's something seriously out of whack. Until my hot end issue, the printer performed flawlessly for about 3 months.

I'd post a picture but because I'm new I can't. Something the moderator might want to rethink.

So what changed to get the Z axis so seriously out of whack, and how do I unchange it?

 

Oh, should probably mention... Robo3D R1+

 

Ok. Well, here's a dummy third post so I can attach images. Images shortly...

 

Ok, hot end showing the location about 2 inches above the glass. I can lower it, but as soon as I try to rehome it raises itself again.

Switches on the left and right side

 

Does the head end up rising during the bed leveling procedure? If the carriage is too tilted from left-to-right I've seen that happen, some or all of the 9 steps (3x3 grid) where the leveling procedure lowers the head until it touches the bed it ends up only raising it instead. If that's the case you'll need to manually turn the left and/or right threaded rods to make the carriage more level. It would appear that both sides are properly resting on the nut that rides the threads, that was an issue for mine as I received it.

I had everything level and working pretty well, then attached a full graphics display last night. While adjusting the Z axis using the controller's knob I found that it doesn't stop when the limit switches are hit, so the head bottomed-out so badly that it completely removed the nut from the left side of the carriage. Getting it back on was a real bear, and then I had to spend about an hour getting the bed leveling to report level again (including cases like the above where some probe steps would only raise the head further into the air). And after all that it totally jacked my Z-offset as well, before this 'event' 0.95 was my optimal setting, now it's 1.15. I guess the adjustments to the leveling (I think I did slightly better this time around, though I just read about using hole-punches as shims so I can probably do even better) resulted in a different offset than before.

 

I don't think leveling is my issue. The carriage is fairly level, and stays level during the process.

 

Well, I spent quite a bit of time looking at wiring, right back to the controller. I found nothing.

Thinking about the switch being hit, I was puzzled because it wasn't even close to touching the glass. In every other aspect it was performing as expected.

Well, the answer was right in front of me, but blocked from view by the case. The cable bundle in the picture to the right of the motor was a little to the left, right behind the motor. As the hot end moved down, the motor caught on it and triggered the switch. I moved it out of the way and all is good.



So my principal problem is solved, but that leads to a second albeit non-critical problem. What is the correct routing for that cable bundle? I know it's connected at the top by a zip tie, as I had to remove it when I removed the top. I put it back in place by memory but there's a good chance I got the details wrong. Could someone post pictures showing how it's routed around the veritcal screws and posts, and how it's connected at the top? I'd like to prevent this problem from recurring.

 

Also, when I removed the bottom to check electrical connections, the cooling fan disconnected. I can't seem to find where it connects. I was able to find a diagram of the controller, but it doesn't show where a cooling fan would connect, and I can't seem to find a connector anywhere else.

 

David I posted a dropbox pic link to your profile page showing the routing of the wires from my stock R1 plus. HTH

 

I should probably note that in the last year I haven't had a single successful print. Every time I go at it I spend several hours only to walk away frustrated and no further ahead. I've replaced the hot end twice and always wind up with a jam before I can get anything out. I've tried replacing the filament. Nothing keeps this from jamming.

My last new hot end jammed the second time I tried the test print. I canceled the first when it failed to extrude, so I adjusted the Z axis. Jam, jam, jam, jam, freaking jam. So I disassemble and clan the hot end. Putting it back in place, the nut that holds the bolt in place for the hot end bracket fell out. Now I've got the whole printing assembly half disassembled and I still can't reach where it needs to go. This is typical of my experience with this machine. It needs way too much maintenance and nothing is accessible. I've easily spent 100 hours trying to get this thing to print.

I've had projects canceled and on hold, and I've had to contract out printing I should be able to do myself. Right now I've got a very expensive paper weight that is nothing but a time sink and a source of incredible frustration.

 

Yes to the PLA. Yes, I've tried seasoning. That appeared to make it worse of all things.

The sad thing is I did just unbox and print. I was printing fine for 3 months before I started encountering problems, but they've been non-stop ever since.

 

Apparently a late night rant was all my printer needed. In the morning I reassembled everything and have been printing all day.

I am still having issues printing small objects (large objects print fine), but I'll open a new thread for this.