Intro: Low Upkeep 3D Printer Bed Adhesion
I started 3D printing a few months ago, and immediately, I understood all the memes about prints not sticking to the bed. I wondered how anyone could possibly get their prints to stick to the bed, yet it seemed like everyone had it figured out. Through some research, a lot of trial and a lot of error, I've come up with a way to keep my prints sticking to my print bed, prioritizing low upkeep.
I'm lazy. I read all these articles about people finding the magic solution to fix your bed adhesion. All you had to do was take some old prints and put them in a custom machine to create this sort of PLA paste, cover everything in hair spray, and download better slicing software.
Now I'm telling you I've found a way to keep my prints attached, using slic3r (a totally free, open source slicing software), and one reasonable purchase from amazon, with prime shipping.
(I've included pics of a few "spaghetti monster" prints that disconnected from the print bed half way through)
Step 1: Switch to Advanced Mode in Slic3r
This step sounds ridiculous, but will help you a ton in the long run. Even as a total beginner, I found the "advanced user" setting to be tremendously useful. In essence this allows you to further customize the creation of you gcode. This gives you more control over some specific things that will be important later. And if you totally mess something up, you can always just reset it to default!
Step 2: PEI
First things first, I bought a sheet of PEI. If you're not familiar, this is a fairly well known print bed surface to help make your prints stick. A friend recommended this to me, so I gave it a shot. I also researched several tapes and pads and glues to layer over my stock glass bed, but this seemed the easiest to remove if it didn't work, and was definitely on the cheaper and easier side, being found on amazon.
https://www.amazon.com/gp/product/B074XLD5QH/ <-- This was the size that fit my printer, but you'll want to get one to fit your specific printer, they come in all common sizes.
This stuff is fantastic. First, I just clipped it on, and found it worked pretty well, and was super easy to remove because it was literally attached with binder clips.
Now, feel free to put this stuff to the test before sticking it on more permanently, but there is a super cool reason why sticking it on is important:
I was having some trouble keeping the small points stuck on the print bed as the part got taller. This has to do with torque, since torque is proportional not only to the force of the nozzle bumping into the print as it moves, but also to the distance between the force and the axis of rotation, which in this case is the print bed. This means, as your print progresses, it can becomes more likely for the parts to detach from the bed.
An additional problem I found with this, was that the sheet of PEI would move. Although it was locked in horizontally, it had some give, and as it was printing, the sheet would flex, providing substantially more opportunity for the part to come loose. Once I stuck it down with the included tape, my bed adhesion improved DRAMATICALLY.
Although I haven't tried buildtak or various masking/painter's tape solutions on my personal printer, I've used them a bit on my school's printers. As the title implies, PEI seems to be the lower upkeep solution, and in my experience, works great.
***A quick note on using the tape, I was surprised to find that the tape was less like a traditional double sided tape, and more like an enormous square glue dot. Not only that, but an impressively sticky one! When I first laid it down over the glass bed, I misplaced the first corner, it was a bit off center, so I tried to pull it back off. This would have worked with normal tape, but with this super glue dot tape stuff, it got stuck and actually ripped off the corner of the glue, as it stuck better to the bed than to the parchment paper type stuff. Long story short, I'm currently missing the tape on one corner of my print bed, but it's never really been an issue.
Step 3: Relevel Your Printer Bed
Levelling your printer bed is important because if its too far away then the filament won't stick. If you read the instructions on the PEI sheet (which I didn't), then you'll know that you have to relevel your bed after you stick on the PEI. This is due mostly to the added height of the sheet, but with the glue it may also change the leveling. For my printer this was fairly simple. Many higher end printers will have auto levelling features, but mine was manual:
- Set the z axis to 0
- "Disable stepper motors" allows you to manually move the motors.
- Move the printhead to all 4 corners, then slide a single sheet of paper between the hotend and the bed.
- Turn the knob under the bed in the respective corner until the paper can just barely slide under it.
- Finally bring the printer head to the middle of the bed to see if the it's still level in the center. If it seems off, check the corners again.
- If you want to be extra thorough, you can then move the head to random places on the print bed to check the levelling.
Step 4: Brim
I've used rafts before when printing stuff on my school's makerbot, so I tried that at first. I was having trouble however, because the raft was auto generated to the size of the print base, and you could not adjust it. I was searching for something like a raft, but that I could extend as far out as needed, and that had a better connection to the base of the print, and that didn't waste so much time and material building up all those extra layers. It turns out, there is something designed to do just that! This magical setting is called the "brim." You can find this setting under "skirt and brim."
- For things that have a large, flat surface resting on the bed, I often don't need any brim at all.
- Any time I have supports or have a few nearby points of contract, I will use about a 10mm brim.
- For any prints that have a small base and are really tall, or for whatever reason I don't think will stick well, I use a brim of 20mm.
- Any time I get frustrated with something not sticking to the bed, I'll use a 30mm brim.
- As I mentioned earlier, torque increases as the height of your print increases, so taller prints will require a larger brim.
Using a brim will make your prints take a little longer, and use a bit more filament, but in my experience it is overwhelmingly worth it. It even helps catch extra filament strings that have oozed while the hotend heated up, and generally cushions other issues from becoming worse.
Step 5: First Layer
This was a little thing that ended up being utterly crucial. Although i will often print with a layer height of 0.1mm, I set my first layer height to 0.4mm and set my first layer speed to 20mm/s.
You're welcome to test out slightly less overkill configurations, but in my experience, this works just fine and doesn't end up getting in the way that much. Remember, these settings affect both the first layer of the print, as well as the brim.
Step 6: The Only Upkeep You'll Have to Do
Now, the only sort of upkeep I've ever done with this configuration, is to clean up the print bed occasionally. I bought a box of those little alcohol pads, but a bottle of isopropyl alcohol and a paper towel would work just fine too. Anytime I'm about to print something important, or I see the print bed getting dusty, I'll just grab one of these pads and wipe it down real quick. It evaporates super fast because the bed is heated, and only takes a second.
This type of setup is only possible if you generally keep your print bed clean. I avoid touching the bed in the middle if at all possible, because the oils from your hands can reduce adhesion. I always clean off any random strands of filament and stuff when I go to pick up a print, and I try not to scratch the bed with the spatula I use to lift prints.
Use these simple strategies, and your nightmares of 20 hour prints breaking off when you're not looking will finally be over!