I borrowed Ender 3 (review) from my local Hackspace. I needed an unmodified printer to draw the parallels between the original design and the latest Ender 3 v2. As the hackspace printer is used by everyone, it needed TLC before the printer was capable of printing fault free. If you are getting started with 3D printing, following these steps will keep your printer in good shape for a long time.
Bad prints, basic problems
It’s tempting to simply jump the shark and post your problems on relevant 3D forums hoping someone will solve it for you. We all feel lost at first looking at all the print options and settings available in Cura or similar slicing software. In reality, the default printing profile should work just fine for PLE without tweaks. If the printer gives you troubles, take a look at possible mechanical issues that are quick and easy to fix.
If you look after your printer on a regular basis, the printer will look after you as well and won’t cause unexpected troubles.
Keep it clean, neat and tidy
3D printing can be a messy business. Filament drops on the floor, it gets into aluminium extrusion profiles and what’s worse, it gets trapped in places that can cause failed prints or even more serious damage. As much as I love my robotic vacuums, it’s not a task for these machines. Elbow grease and the moist cloth will be very useful.
Once cleaned, consider printing V-Slots covers to prevent the filament from getting inside while this fan hood will keep the motherboard filament and dust-free. Once vacuuming is done, use a damp cloth to wipe the rails and wheels.
Your printer should spark by the time you get to mechanical tasks, so let’s go over the most important maintenance tasks for the printer. Before you get the Allen keys out, inspect the printer visually. Look for signs of wear of physical damage. Check roller wheels, belts, moving parts.
Inspect the frame and look for play between components. You can take the carpenter’s square to check the right angles. Any discrepancies should be fixed by loosing up the bolts and re-adjusting the pieces so they are art right angles to each other.
To inspect the rollers properly, undo belts or release the shaft clamp from Z-axis. Each axis should slide along the aluminium extrusion profile easily, friction-free and without any play. If you notice any play in movement, high resistance when rolling or lack of alignment, you will have to adjust the roller screws.
Each screw is terminated with a nylon nut. This will keep the roller wheels firmly in place and prevent the wheels from wobbling. Too much tension can lock up the wheel or cause excessive friction and wear to the surface of the wheel. If you noticed that wheels have the sign of wear, you will need to order replacement ones. These are relatively cheap and easy to swap.
One of the wheels will also have a hex nut instead of a cylindrical standoff. This is an adjustment screw, To eliminate the excess play, tighten that nut slightly. It will cause the rollers to clamp more firmly around the guide slots. Do so until the entire carriage slides without play, and it’s still friction-free.
Tensioning belts doesn’t have to be done often, especially if you do this right. Ender 3 v2 comes with belt tensioners equipped, but you can also buy these separately or print it yourself. The type of tensioner will depend on the aluminium profile size. Ender 3 use 2020, 2040 for X and Y-axis respectively.
To tension the belt, drive it through the pulleys and secure in place, then screw in the tensioner screws ever so slightly. Once you feel the bite, ease off a little bit and use your fingers to push out the tensioner as much as you can. Clamp it with bolts and the belt should not sag, but should not be overly tensioned.
As you work on different axis, check the Z rod. It should be straight, the X carriage should be firmly attaches to the guide ring and the shaft shouldn’t have any play. Check the shaft clamp as well. Once you are happy with the condition apply a little bit of grease across the rod to keep the motion smooth.
If you have a plastic extruder cage, check for wear. The filament can dig in overtime into plastic creating snag points. Invest in a metal dual gear extruder if yours is knackered. Check the alignment of the pulleys. These are kept on the shaft with a grub screw and should be on a level with the guide hole for the filament.
Lastly consider the Bowden tube and the fitting. Twisting tubing can cause severe damage to the tubing. If you want to insert or remove the tube, pull down on the release ring. Inspect the tubing end, it should be cut at the right angle (with a tool like this). Check inside of the fitting. You should see metal teeth that hold the tube in place. Fittings with missing or bent teeth should be changed. I used these ones, it’s good to get a stock of them.
Clean and inspect the hot end on regular basis, especially the nozzle. The filament can build up inside and clog it up. If your nozzle is a bad shape, consider changing it (It’s wise to keep a stock of them just in case). You might be tempted to heat it up if you cannot remove the parts, but metal expands with heat, and you are likely to seize it more. If your nozzle is stuck, unscrew the heat block (gently remove the heating barrel and thermistor (small probe to measure the temperature) and stick it in the freezer for 30 min.
The hot end can be disassembled too. It’s good to have a blow torch or naked flame nearby to warm up parts and scrub the filament off. Clogs inside the metal tube can be removed by heating the metal pipe over the flame and pushing a spare piece of Bowden tube through to push out the plastic.
If your heating element is stuck (watch for the grub screw), you can push it out with a punch, but don’t hammer it down, just bump it gently. Heating it up is a bad idea, use canned air to cool the parts and cause the metal to shrink. Feel free to use fine sandpaper to gently smooth out the heating element. Cleaned up metal has much better heat transfer properties.
Capricorn tubing has a higher temperature resistance. It’s also more expensive. Since your hot end is in pieces, you might as well implement this quick fix (you can use standard tubing as well). You could use an online guide to get the estimated length, but hot ends are not made equal, and that value can vary. Don’t forget to print out this washer to keep the modded tubbing in place.
Lastly, for printing materials that need higher temperatures, you could consider an all-metal hot end like this MicroSwiss drive. It’s expensive but enables new printing materials on your Creality printer.
Remember to check the tube fitting in the same way as you did with the extruder.
Correctly levelled (trammed) bed will eliminate a lot of problems. From layer adhesion to issues with inconsistent prints. Levelling isn’t necessary every time you print, in fact, if you feel that you need to level the bed each time, you might have other underlying problems with the printer. I level the bed once every couple of weeks and each time I move the printer around.
Improvements like BL Touch can aid the process, but even with this upgrade, you should still level the bed from time to time. If you already use BL Touch, it’s the nozzle offset that you will care about a lot, but that’s a subject for another write-up.
Start with bringing the bed down so each spring holding the bed up has about 1-2mm space between coils. It should look squished, but not compressed to the max. Locate the Z stop. It’s the push switch that stops the gantry from moving into the print bed. It should stop the printhead as soon as it is touching the bed. Check the mounting screws, as if Z stop slides down, you will never level your bed.
Level the bed 2-3 times each time checking each corner. Once levelled correctly, heat it up for 5 min, cool it off and level it again. If it holds true, you are good to go. If you feel that your bed is warped and you cannot get it in level with gantry, avoid flexible print surfaces and consider glass bed until you can get the replacement part for your bed.
A looked-after 3D printer is a happy printer. Schedule a check-up with your machine every 2-3 months based on the usage, and it will serve you for a long time. Printing forums are filled with horror stories and complaints about the machines not performing as they should. Frankly speaking, I’m surprised, as my Ender 3 never gave me any hassle. If you feel like this list could use other tips, let me know in this Reddit thread.