A few days ago I mentioned that our 3D printer now has a glass print bed. That wasn’t exactly a planned upgrade; in the process of removing a print from the standard bed I pushed a little too hard with the scraper, and it dug a lump out of the top surface. That’s the problem with a flexible fibreglass bed under a stick-on work surface – in a contest with steel, it’s always going to come off worst.
Anyway, I plan to repair it by cleaning it off and sticking on a new surface, but this gave me a good opportunity to test a glass bed, so I ordered one and gave it a shot.
What’s In The Box?
The bed I chose is an original Creality glass bed, specifically designed for the Ender 3. It came well packed in a slim cardboard box, with the bed secured in a foam block that should protect it from any shipping mishaps.
The bed itself is a chunky slab of temperature-resistant borosilicate glass. It’s 4mm thick and has nicely finished edges. The top has a slightly textured surface, which Creality say is made of carbon and silicon. This surface is supposed to give excellent adhesion and avoid the need for tape or hairspray.
I just ordered the bed itself, so it didn’t come with any clips. However, the ones I’d been using for the standard bed work just fine with the glass one too. Attaching it was very easy, and re-levelling the printer was just as simple.
What’s The Point?
Glass has a couple of major advantages as a 3D printer bed material. Firstly, if you go with borosilicate glass like this it’s very heat resistant. The Creality bed is rated to 400°C, which is a long way past anything an FDM printer is going to reach. It’s also hard, so your scraper isn’t going to be gouging lumps out of it. Finally, it’s very rigid. Glass can bend to a limited extent, but a relatively small, thick sheet like this one isn’t going to. Once you have your shiny new glass bed levelled, you can rely on the surface being absolutely flat.
This bed is also extremely durable. The surface is highly scratch-resistant, and a wipe with isopropyl alcohol will take off any plastic residue and other marks. The standard bed was starting to show some signs of wear and tear even before I mangled it; that isn’t going to happen with the glass. Unless you drop it on a hard floor, this is pretty much indestructible.
How About Adhesion?
I already mentioned that Creality say the surface on this Creality glass bed means you won’t need to use tape or hairspray to get things to stick to it. I have to say that, apart from a couple of issues with my old friend PETG, I never had any adhesion problems with the standard Ender 3 bed. In fact, things generally stick to it so well that they sometimes need considerable effort to remove – which of course is how I came to rip it up with the scraper in the first place. So, does the glass bed match up to this standard?
Honestly, no. It doesn’t. I had no problems at all with standard PLA, or with nylon. On the other hand, HIPS and a couple of PLA variants seemed to find it a good deal less grippy, and I had to resort to either blue tape, adhesive spray or on one occasion both. One plus is that if you do need to use tape or spray, any residue comes off the glass very easily.
On the other hand, removing completed prints from the glass is easy. In most cases, all you have to do is let the bed cool down. As it cools it contracts slightly, and that starts to break the bond between print and glass. Once it’s at room temperature you can generally pull the object off quite easily. A couple of larger prints were a bit stubborn, but a firm twist and tug shifted them. I’ve got into the habit of removing the bed and flexing it to pop prints off, and I was a little worried about not being able to do that, but so far it hasn’t been a problem.
So, should you upgrade to a Creality glass bed? I’d say that depends on what you print with. For materials that might not give the best adhesion I think the standard bed might be a better option. On the other hand, if you mostly print in PLA I think this bed makes a lot of sense. It’s robust, outstandingly flat and easy to level, and should pretty much last forever.