Is there a Maintenance Guide?

So I’ve had my printer for over a month now, and it’s be printing daily. I’m starting to get more ripples in prints, and I’m sure it’s likely a cleaning issue. The problem is, I really don’t see any form of detailed cleaning guide. The closest I found is https://www.lulzbot.com/maintaining-your-3d-printer but it’s pretty generic. I was expecting something a little more detailed.

Cleaning the rods when simply wiping them down doesn’t clean them. I’ve lightly cleaned mine with #0000 steel wool, but it’s hard to get all sides clean. Should one pull them out and clean them properly? Is it better to clean them with something like isopropol alcohol after using the wool on them?

The threaded rods and lubrication… what’s the best way to apply lithium grease to them so as not to under or over apply it?

Cleaning the print bed. I notice after pretty much every ABS print, there’s a whitish coating left on the PEI that Isopropol alchohol doesn’t always take off. Is there a better way to clean it?

Bunch of stuff like that. I didn’t see anything searching the forums and wondered if anyone has come up with a cleaning regime they would like to share with me and others.

Thanks!

Hello Teddy,
I thought I might step in and give a little support. I worked in our cluster where we run 144 printers.We have some tips for you.

You have the right approach on the guide rods. Use the steel wool to clean the rods and then alcohol will remove residuals left. This will give the Bushings a smoother surface to ride on.

The threaded rods that you coat with white lithium grease can be applied with either using latex gloves or a good rag. Once you apply the grease and run the Z axis up and down a few times, it will cause the excess grease to bunch up at the ends of the threaded rods, where you can wipe the excess off.

As far as the “whitish coating” that is left on the PEI, this is normally left from residual ABS attaching to the PEI, but it is also due to the PEI surface breaking down over time. We choose to resurface the PEI with a sanding block(from Home Depot) and a sheet of 2000 grit sandpaper. If you will get a spray bottle and mix 90% water with 10 % alcohol and spray down the PEI surface. Then wet sand the PEI lightly. A whitish film will appear. Simply clean the film up with the same mixture. Then you will have a re-generated PEI surface. ABS will then adhere better and you will have less residue. This will last quite a while, but due to the nature of ABS and PEI interacting it will have to be sanded periodically. I hope this information is helpful!

Good info! Especially the detailed description of the PEI wet-sanding.

Great info, David.H. Thanks for the detailed description.

Do you find it’s helpful to remove the rods when using the steel wool, or are you able to get them polished up enough while still in the printer?

Thanks… this is pretty much what I did.

For the PEI I used the same #0000 steel wool (that I use on the rods) on the PEI surface, then wiped it down with 90% isopropol alcohol. It leaves the PEI incredibly smooth, but it makes it even harder to get ABS prints off it. I will see if the sandpaper leaves a bit rougher surface.

Heat Sink Fan Maintenance:

I’ve only owned my Mini for a couple weeks now, but I was surprised at how much crap has built up on the little micro blower (heat sink fan). If you look at it with a bright flashlight and magnification, you will probably see lots of fine lint on the vanes. I blew mine out with compressed air, being very careful not to spin up the fan too fast. Not only did a good amount of dust come out, but I also had some PLA fine strings that couldn’t have been good for longevity. This fan seems a bit small to be adding a filter to it. Ignoring it could cause undesirable behavior of the extruder though, or failure. YMMV.

This is shaping up to an interesting thread for us newbies. It sure beats learning some of this by trial and error. I hope the suggestions keep coming. Maybe some of this will end up in the next version of the manual.

Checking & Matching Your Z-Axis Stepper Motors:

Your Z-Axis has two stepper motors, one on each lead screw.
Since they are both stepper motors, they should always be in sync.
When the motors or the supply are “off”, they can be moved, and they may get a few steps off. Shipping is a good example.
These are also “open loop” stepper motors, so a dropped count will go unnoticed by the controller.

The best way to check if they are fairly close is to print a 100mm x 100mm box on the print bed, and watch the Z-Axis motors as it moves in both X and Y directions. Slight motion is normal, but if your steppers are out of sync, you may see it compensating as it moves across.

Since the motors are on opposite sides of the X-Axis, this is the most likely part you will need to correct.

Using Cura, load any simple model, launch Control, and use the position Z, Y, and X to bring the print head down on the near-left zeroing pad.
(Note: clean off any boogers from the print nozzle as needed so you can get a clean contact) Get it close with Z, then adjust X and Y until it is where it would normally touch down during an automatic bed leveling process. Then bring Z down in small steps, 0.1mm at a time. Watch both the contact point and the Cura screen. When the print tip touches the leveling disc, the next step will report that it is at a limit, and you won’t hear it move. Back up and re touch several times. Then raise up 1 mm by hitting the up-Z 1mm button. Then move X across to the other leveling disc. Repeat the approach process using the down 0.1mm button until you get more limit reports. Compare what the numbers were (in the Cura GUI) from the left disc to the right disc. Your goal is to get them nearly perfectly matched, but if it’s off by 0.2 I wouldn’t worry much. Cura will report the position in hundredths, you will be moving in tenths (of millimeters). The counts should be fairly repeatable, but if they aren’t, clean your nozzle and try again.

To correct any difference, note how much of a rotation of the Z axis flex coupling is needed to move the amount of your error. Then do a “Motors off” button push (in Cura) so the steppers won’t try to hold their position. Rotate the appropriate shaft to remove this error and recheck your alignment. This is the tricky part - trying to determine which way your Z axis needs to rotate. Make small changes and take notes until you are sure you are moving in the correct direction. Pressing Z-up or Z-down will turn the motors back on in Cura. You will need to do a “Motors off” button push each time before you try to rotate the shaft.

You can check the front to back Y-Axis tilt the same way. If it’s off, you will probably need to shim the mounting brackets to correct it. Mine was very close in Y, but my X was off about 0.5mm, or about 1/4 turn of the shaft. I used the right shaft to make corrections as it was easier to reach. I can barely see my Z axis move as it traverses across the bed while printing now.

When you’re done, print your 100mm x 100mm square again and note how little the Z axis moves now.

If your bed is extremely tilted, you may have excessive mechanical load on the motors, or other issues.

Hope this helps! Please let me know what I may have missed. Thanks.

Here’s a sample from my Cura GUI, and the bottom two numbers are after I changed the Z-Axis ever so slightly on the RH lead screw:

< echo:endstops hit: Z:-155.00
< echo:endstops hit: Z:-155.00
< echo:endstops hit: Z:-155.02
< echo:endstops hit: Z:-155.00
< echo:endstops hit: Z:-155.00
< echo:endstops hit: Z:-154.95 <-- Multiple touches of the left front disc
< echo:endstops hit: Z:-154.95
< echo:endstops hit: Z:-154.95
< echo:endstops hit: Z:-154.95
< echo:endstops hit: Z:-154.95
< echo:endstops hit: X:117.29 <-- This is when I moved to the other side (right front disc)
< echo:endstops hit: Z:-154.75
< echo:endstops hit: Z:-154.76
< echo:endstops hit: Z:-154.76
< echo:endstops hit: Z:-154.79 <-- Multiple touches of the right front disc
< echo:endstops hit: Z:-154.79
< echo:endstops hit: Z:-154.79
< echo:endstops hit: Z:-154.97 <-- Result of my slight adjustment, happy with that.
< echo:endstops hit: Z:-154.98 <-- Again, to show repeatability

Here’s another tip I learnt for buzzing when the heatbed goes back and forth.


I decided to track down buzzing in my Y axis (headbed).

Usually it’s from the screws under the glass that attach the aluminum sheet to the bearing holders that work their way loose. I’ve been told I can use Loc-Tite Purple on these, but to avoid Red or Blue as they contain acetone which can melt the ABS and screw up the heat pressed nuts.

Well this time, it turns out it was the screws at the back and front of the printer that hold the rod blocks to the metal frame. 4 bolts on each end worked their way loose. One was missing, I’m not sure if it was like that when I got it or not, but I had a spare couple kicking around from my RC car parts.

Time to order up that Loc-Tite Purple from Amazon and get those to stop coming loose.

While you’re at it, check the screws that hold the stepper motor in the back to make sure they haven’t loosened as well, which mine were.

NOTE: do NOT over-tighten as you risk pulling out the heat press nut from the ABS.

Thought I’d mention this resource:
https://ohai.lulzbot.com/

I noticed the post about the guide rods and cleaning them with steel wool. I have never had a reason to remove them for cleaning. Simply surround the rod with the steel wool and use light pressure. The cleaning with alcohol is important afterwards, as the bushings are self lubricating and you don’t wish debris to accumulate.

I enjoyed reading the Z axis stepper motor “in sync”. Something to go along with that is to verify that you don’t have any Z axis binding in your Taz, that will cause a slight drift in your X carriage. This can be caused by moving your printer frequently or having it jarred significantly. To ensure that both Z nuts move smoothly on the Z axis threaded rods, try this approach.

To adjust the Z binding on the Taz, you must first locate the 4 Allen head screws that attach the X carriage assembly to the Z nut mounts. Once you have located them, then you will loosen all 8 Allen head screws, 4 on each side. After this you will need to Auto home the printer. Then move the Z axis to close to the top of the printer using CURA (245mm from home). Then re-home the printer again. Do this 2 times bottom to top and back. Then move the Z axis to the middle of the printer. Once you have the X carriage in the middle of the printer, re-tighten the 4 Allen head screws connected to the Z nut mounts on each side.
Please do not over tighten the Allen head screws.
Once this is completed, run another print and see if the Z binding is decreased.

Just a little information I thought may be helpful.

I also noticed on the Mini that over time, the bed can have a little play in it. You need to take off the level pads, lift up the PEI board, and then tighten all of the little black bolts. The PEI board should not have any play it in it. When it is really loose, you will noticed the whole bed making little X shaking movements while printing (not the Y movement from the pulley)