A popular first modification that users will make for their 3D printers is to install a glass bed. Some 3D printers come equipped with glass for the build surface but many others are upgraded to a glass.
So what is it about glass that makes it so popular?
Glass beds are a popular choice of printing surface because they provide a smooth, flat and durable build surface at an affordable price. A boroscillate glass is an ideal solution for this application because of its tolerance for high temps and resistance thermal related failure.
In this guide, we will see that glass has a lot going for it! It is not only affordable but it is also consistent, durable, convenient, easy to work with and simple to maintain. Let’s look at these advantages one by one.
Advantage #1: Smooth Surface
The number one reason most people use glass as their preferred bed is that it provides a very flat build surface and that allows for a more consistent first layer.
A good 3D print depends on the first layer and that first layer relies on the printing bed. Glass can withstand a lot of stress as it has a high modulus of elasticity and this means that the bed will stay flat.
An inconsistent first layer could easily affect the rest of the print so this first step is really vital to ensure a successful print.
Tip: Clean glass with give result in an even better print!
Any imperfections of the bed will reflect in your parts so a bed that doesn’t easily develop faults or surface inconsistencies is crucial.
Also, the smooth surface of a glass bed means that the face down portions of your prints will get a beautiful smooth finish!
Advantage #2: Durability
Reason number two is that it is very durable. Unlike other build surfaces glass is very difficult to damage during your typical 3D printing usage.
Alternative surfaces are often based on plastic or aluminium and these can easily get warped, scratched, and otherwise damaged after a number of uses.
The cost of replacing them can quickly add up. Glass, on the other hand, is naturally harder and more resistant to repeated use.
So over time, the long lasting durability of a glass printing bed will save you time, money, and effort.
Advantages #3: Convenience
There are some simple matters of convenience, glass conducts the heat evenly all throughout the bed. Thus it also cools down evenly which reduces the risk of any warping or deforming.
As opposed to other materials, glass doesn’t expand as much when heated so it doesn’t contract as much when cooling down.
During cooling, the parts will contract at a higher rate as compared to the glass bed and this means that they will come off easily. There’s nothing worse than forcibly having to remove a print from the surface and risking damage after so much effort.
Tip: Bump up the temp on your heated bed an extra 5-10 degrees to ensure good first layer adhesion.
Advantage #4: Cost
As I’ve alluded to before a glass bed can really save you big money in the long run. Replacing your bed frequently due to damage can really add up. Since glass is durable it will not be replaced as often as other bed materials.
This glass bed, for example, is just $17 <link 1> while this alternative one is $11. <find buildtak>
Of course, there are a variety of materials with a whole range of prices but I would not hesitate to spend a little bit more on a good glass. That one-time investment of a few dollars more will save me money from replacing damaged beds on a regular basis.
Advantage #5: Maintenance
A glass is easy to clean too.
It’s highly recommended that the bed be cleaned thoroughly before and after every use. It only takes a few minutes to wipe it down with some common glass cleaner or acetone.
This removes any dust or plastic particles from previous jobs and ensures a nice even surface before printing.
In this case, the big advantage of a glass bed to any other alternative is just that it’s so easy to see the dirt and to make sure that it is spotless.
Can you use any type of glass?
It depends. Some people use regular glass, the kind that can be found at any hardware store. Regular window glass can shatter when exposed to rapid changes of temperature so the ideal solution is to use Boroscillate glass.
Boroscillate glass, a mixture of boron trioxide and silica, is the preferred material because of its durability over numerous thermal cycles in comparison to other types of glass.
A thermal cycle is the process of going through two temperature extremes, i.e. cold to hot.
Moreover, boroscillate glass has low thermal conductivity (meaning that it is resistant to sudden heating or cooling) and thus thermal cycles will not warp, crack, or break it.
As you can imagine plastic basis are far more likely to get damaged by temperature changes.
In simpler words, it’s not easy to damage boroscillate glass and so it ticks all our boxes: it’s smooth, convenient, cheap, easy to maintain, and most importantly it is very durable.
It’s clear that this makes a fantastic bed for our 3D printing adventures!
Keep in mind that if you’re using very high temperatures your best bet is to use a thermal resistant glass like boroscillate. Regular glass beds will slowly lose its strength and may eventually break.
If your printing often requires these extreme temperatures you will need a glass with high thermal fatigue resistance.
How do you attach the glass to the bed?
Your glass bed will not be of much use if it is moving around during printing. The two main options for attaching the glass to your bed are1,
- Silicone, non-adhesive thermal pads: these will hold down the glass and at the same time allow the heat to be transferred from below. This is the approach I like the best.
- Strong binder clips or 3d printed clips: these hold the glass down directly to the aluminium without allowing it to move or slide during a printing job.
Fun tip: On Thingiverse, you can often find clips for your printer! <link 3>
Buying your Glass Bed – More Considerations
If by now you are convinced and want to start looking around for your ideal glass bed, keep these 3 points in mind:
- Thermal Shock Resistance: We’ve already touched on this point. Whichever glass you choose must be resistant to high temperatures as well as sudden extreme changes of temperature. The glass should be able to withstand heating at up to 200°F (94°C) and a sudden drop to 40°F (4.4°C).
- Thermal Fatigue Resistance: Working hand in hand with shock resistance is fatigue resistance; the ability to withstand continual repeated temperature changes. Normal or even tempered glass will lose their strength over time if they are continually heated up and cooled down. A boroscillate glass is an ideal candidate because it has a high thermal fatigue resistance – it is not affected by temp changes.
- Size: Make sure that the glass is the same size as the bed. You obviously don’t want it to sway to and fro during a printing job. In addition, a typical good glass bed is about 3 to 4mm thick. Any less and it will be susceptible to cracking. Of course, if your print bed is bigger your glass should be thicker.