"Repeatedly touching your PEI film with your hands may leave a residue over time. Periodically clean your PEI film with isopropyl alcohol (IPA). Use unscented IPA, in a concentration over 70%. Apply the IPA to a clean, dry cloth or paper towel and wipe the bed to ensure a clean PEI printing surface"
While we no longer use PEI printing surfaces, the above recommendation is the same for the flexible magnetic surfaces.
Wiping down the surface is also a good time to check its condition. If you notice light scratches or minor gouges, LulzBot recommends using fine-grit sand paper (1500+ grit) to gently remove them. This can be done several times before the flexible sheet will need to be replaced.
If cleaning the bed with the IPA solution and sanding no longer seem to be helping adhesion problems, it is likely time to replace the flexible sheet. Please contact Sarah Holland to have new flexible magnetic sheets ordered.
From the TAZ Workhorse manual:
"Keep the washers mounted on each corner of the print surface clean and dust free by wiping them periodically with Isopropyl Alcohol (IPA) on a paper towel or a clean dry cloth. If the bed leveling washers are not clean during the bed calibration process the print surface or tool head may be damaged. Never attempt to clean the bed leveling washers during the probing sequence as it may lead to personal injury. "
Maintaining the wiping pads is important to make sure the nozzle is able to clean itself at the start of each print.
If you notice a small amount of filament on the wiping pad, you can use a scraper or tweezers to remove the debris.
Over time, the nozzle wiping pad will become filled with plastic residue. The pad can be flipped over once and will need to be replaced when both sides are full.
Dirty wiping pad vs. a clean wiping pad
For instructions on replacing the wiping pad watch this video. The video shows a Lulzbot Mini, but the process is the same for the Workhorse and Mini 2.
Even with a clean wiping pad, filament can build up on the nozzle and hot end.
To clean the nozzle, pre-heat the hot end to around 230 degrees (to be able to clean both ABS and PLA from the nozzle) and then carefully wipe the nozzle off with a scotch brite or similar pad. Wear heat resistant gloves to protect yourself!
Do not use metal on the nozzle while plugged in/turned on as this can create a short!
MatterHackers explains the importance of a clean nozzle: "First off, let me explain how the LulzBot TAZ 6 levels the bed: there is a wire that runs from the board to the heater block, where it is mounted using a small screw, and another set of wires that run from the board to each of the four washers that clamp onto the bed. Before each print, the LulzBot wipes off the nozzle on a small cleaning pad, and then will quickly probe one corner, move away from it, and come at it again slower. Once it taps the washer the second time, it moves onto the next washer until all four have been probed.
Now because it has to close a loop, it needs to make electrical contact, and if there is any burnt or stuck filament on the tip of the nozzle, no matter how hard it presses into the corners it won’t close the circuit and register it as a failed probe."
Clear away any bits of filament or other debris from the 3d printer area. Small bits of filament can get lodged in places like the motors and bearings and cause mechanical issues with the printers. A small hand broom can be used to sweep up large pieces from the area and short bursts of compressed air can remove small bits.
