Z stuck, belts grinding, problems everywhere

A forum dedicated to the stock LulzBot Mini 3D Printer
trollioli
Posts: 31
Joined: Tue Dec 20, 2016 11:22 pm

Z stuck, belts grinding, problems everywhere

Post by trollioli » Sat Oct 06, 2018 11:11 pm

A while back I had a problem that seemed to come out of nowhere. The printer used to lightly touch the contact plates in the corner. After a while it was jamming them down hard. I cleaned the head with a wire brush and then it really started to go crazy. Soon the print head was going off the edge of the print bed so far that the belts were grinding.

OK, I probably blew the mini rambo. I ordered a new mini rambo and in the beginning it was doing the same thing until it descended to the bed where it mashed down so hard that i thought it was going to break it. Now I can't even manually bring the printer head up. Currently it's jammed down on the printer plate and every time I try to either manually raise the extruder or start the print over, the belts grind so hard that I just it off in fear of it messing something else up.

The motors maybe are fried? I'm currently out of ideas. Thoughts?

trollioli
Posts: 31
Joined: Tue Dec 20, 2016 11:22 pm

Re: Z stuck, belts grinding, problems everywhere

Post by trollioli » Sat Oct 06, 2018 11:19 pm

Here's a quick 2 or 3 second video of where it's at and what it sounds like when I try to manually move the print head up from the bed.
20181007_004719.mp4
(5.25 MiB) Downloaded 39 times

Ehoff
Aleph Objects | LulzBot
Posts: 61
Joined: Fri Sep 08, 2017 1:34 pm

Re: Z stuck, belts grinding, problems everywhere

Post by Ehoff » Sun Oct 07, 2018 8:14 am

It looks like you've got some z-binding going on. Usually leveling the x-axis will help correct this problem and we've got a guide that goes over it located here: https://ohai.lulzbot.com/project/leveli ... e-repairs/

The guide shows a Taz 6, but the steps are the same for a Mini.

Also, one thing to keep in mind, is that using a wire brush on the nozzle can cause big problems by shorting out the RAMBo board. We recommend using scotchbrite type pads that are non-conductive to clean residual filament off the nozzle area. After you installed the new RAMBo did you make sure to flash the firmware on it?

kmanley57
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Joined: Sun Feb 01, 2015 3:53 pm

Re: Z stuck, belts grinding, problems everywhere

Post by kmanley57 » Sun Oct 07, 2018 10:02 am

I would also lift the nozzle off the bed(Z screws), as it (I think) tries to home X then Y and if the nozzle is rammed into the bed it will grind both those belts. YMMV.
I will express my CRAZY ideas at any time! So you have been warned. None of my opinions are Lulzbots and can be wrong at any second.

trollioli
Posts: 31
Joined: Tue Dec 20, 2016 11:22 pm

Re: Z stuck, belts grinding, problems everywhere

Post by trollioli » Sun Oct 07, 2018 12:54 pm

Success! sort of... I updated the firmware (didn't even think of doing that) and it actually pulls the extruder up like normal and goes through the process. It still has problems with boundaries though. When it gets to the apex of it's run to reposition itself to start, you hear what sounds like belts grinding. It doesn't quite know it's at the top. Then it goes down to do its automated nozzle cleaning and it just above the wipe. After that it goes to do the sensor pads which it mashes down on, drags over and hits the side of the second pad, drags across the bed half way to the 3rd pad then cuts across like it thinks its rectangular instead of square. I turned it off to save itself from damage but I am much more hopeful now.

So far as I can guess, this is now just a matter of settings.

The next question I have is how do I reset all the settings so it wont go up, down, left, right, to far? How do I get it back to normal?

Galadriel
Aleph Objects | LulzBot
Posts: 279
Joined: Mon Sep 25, 2017 10:23 am

Re: Z stuck, belts grinding, problems everywhere

Post by Galadriel » Mon Oct 08, 2018 12:57 pm

trollioli wrote:
Sun Oct 07, 2018 12:54 pm
Success! sort of... I updated the firmware (didn't even think of doing that) and it actually pulls the extruder up like normal and goes through the process. It still has problems with boundaries though. When it gets to the apex of it's run to reposition itself to start, you hear what sounds like belts grinding. It doesn't quite know it's at the top. Then it goes down to do its automated nozzle cleaning and it just above the wipe. After that it goes to do the sensor pads which it mashes down on, drags over and hits the side of the second pad, drags across the bed half way to the 3rd pad then cuts across like it thinks its rectangular instead of square. I turned it off to save itself from damage but I am much more hopeful now.

So far as I can guess, this is now just a matter of settings.

The next question I have is how do I reset all the settings so it wont go up, down, left, right, to far? How do I get it back to normal?
It sounds like your endstops aren't triggering appropriately, an endstop is small limit switch that tells your printer it is at the end of a build volume and if they aren't working it will cause the printer to either stop short of where it is supposed to or overrun the end of the build volume causing the belt to skip and the motor to grind the way you have seen.
Given the fact that you cleaned your nozzle with a wire brush and then this occurred, in tandem with the fact that it sounds like several of your endstops are malfunctioning at once I am thinking that unfortunately you probably have a damaged RAMBo. For future reference we don't recommend using anything metallic on your hotend, because your automatic bed leveling is done through electrical contact if you accidentally connect two points on your nozzle with something metal it can make a connection between those two points causing static discharge that can travel back through your wiring to damage your control board.

Which version of Cura are you working with? There is a GCode command we can use to get a read out from your endstops which we can use to try to check and confirm if my suspicion is correct, but the way to perform the testing will be slightly different depending on the version of Cura you are working with due to layout changes so I want to make sure I'm sending the right instructions.

trollioli
Posts: 31
Joined: Tue Dec 20, 2016 11:22 pm

Re: Z stuck, belts grinding, problems everywhere

Post by trollioli » Mon Oct 08, 2018 11:42 pm

I've already bought and replaced my mini rambo. I am currently using cura lulzbot edition 3.2.27. Heres a picture of my gcode.

Image

and the second half

Image

trollioli
Posts: 31
Joined: Tue Dec 20, 2016 11:22 pm

Re: Z stuck, belts grinding, problems everywhere

Post by trollioli » Mon Oct 15, 2018 8:24 am

If you blow your mini rambo with a wire brush like I assume I did, would the extruder need replaced too? Would it be giving me all these auto leveling problems?

Galadriel
Aleph Objects | LulzBot
Posts: 279
Joined: Mon Sep 25, 2017 10:23 am

Re: Z stuck, belts grinding, problems everywhere

Post by Galadriel » Mon Oct 15, 2018 2:23 pm

Thank you for those screenshots of your machine settings! Since you are working with Cura 3.2.27 to check your endstops you will want to start by making sure your printer is connected to Cura and that your toolhead and print bed are centered so none of the endstop switches will be held down. Then click over into the Monitor section from the upper left of Cura. From there you will be looking for the button labeled Console in your Manual Control section, click on this and a new window will open up. In the new window there will be a text entry box along the bottom of the screen type M119 into that box and hit enter. Take a screenshot of the resulting read out from the Console.

In answer to your other question if the board has been damaged you would only need to replace the board not the toolhead.

trollioli
Posts: 31
Joined: Tue Dec 20, 2016 11:22 pm

Re: Z stuck, belts grinding, problems everywhere

Post by trollioli » Tue Oct 16, 2018 4:59 pm

Galadriel wrote:
Mon Oct 15, 2018 2:23 pm
Thank you for those screenshots of your machine settings! Since you are working with Cura 3.2.27 to check your endstops you will want to start by making sure your printer is connected to Cura and that your toolhead and print bed are centered so none of the endstop switches will be held down. Then click over into the Monitor section from the upper left of Cura. From there you will be looking for the button labeled Console in your Manual Control section, click on this and a new window will open up. In the new window there will be a text entry box along the bottom of the screen type M119 into that box and hit enter. Take a screenshot of the resulting read out from the Console.

In answer to your other question if the board has been damaged you would only need to replace the board not the toolhead.
Image

Looks like I was wrong. I thought it was the Z stuck when it was the Y that was giving troubles. I guess the next question is how do I fix it?

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