High-rise buildings cannot be built without scaffolding. Each level of the building is built on the previous level with scaffolding playing an integral part in the construction.
Like scaffolding, supports play a key role in 3D printing. As each layer of a 3D print is printed, supports allow each layer to be built successively until you have a complete print. While they might not be needed in all prints, it is impossible to print some geometries and shapes without supports.
As important as supports may be, most makers would prefer to print without them if they could. This is because supports add to the material used, increase the amount of post-processing you need to do, and can damage your prints when it comes time to remove them.
In this deep dive on supports, we look at when you should use supports, how to print so supports are easier to remove as well as how to safely remove supports without damaging the surface of your prints.
When Do You Need Supports?
Several rules of thumb make the decision to use supports easier or more clear-cut. Generally, if there are any overhangs or bridges in a print, then a support should be considered. If the bridge has a length of more than 5 mm, a support will ensure it holds up. Similarly, if an overhang has a tilt greater than 45 degrees then it is best to use a support to keep it from collapsing.
There are several 3D printing technologies and most of them use supports in some form.
|PRINTING TECHNOLOGY||MATERIAL USED||SUPPORTS|
|Fused Deposition Modeling (FDM)||Filament||Yes|
|Selective Laser Sintering (SLS)||Powder||No|
There are two basic situations in which supports are needed.
- Overhangs are where the printer has to print into air as in the letters T and Y. In these examples, parts of the letters are left “hanging” in the air.
- Bridges are overhangs that connect two sides of a print. Using our letter example this would be an “H”. The horizontal bar in the middle connects the two vertical bars. It’s virtually impossible to print this without something to hold the bar up and this is where supports come in.
How To Avoid Supports?
In truth you want to avoid printing with supports wherever you can. This will save you time, material, and the possibility of your print getting damaged in the process of removing supports.
There are a few ways you can cut supports out of your designs entirely.
Change The Orientation Of Your Print
The simplest and possibly smartest thing you can do is to try to orient your print in a way where there are fewer overhangs. For example, printing the letter “T” in an upright position will require overhangs. If you turn the T upside down, now you have the flat top of the T as the base and thus you eliminate the need for a support. Source
Split Your Print
Rather than print one continuous part, something that can save you the need to use supports is printing in two or more parts.
Take a sphere for example. You could print it inside some supports if you wished. An alternative would be to print it in halves with the cross-section laying flat thereby negating a support. Then you can just glue the two halves together.
While these are effective fixes, there are cases where you cannot get around printing with supports. In that case, you might want to make your supports as user-friendly as you can.
How Do I Print Easy To Remove Supports?
Supports are unavoidable when printing some geometries. In cases like these, one of the best ways to make supports easy to remove lies in the design of the print. Limiting the angle of overhangs and the length of bridges minimizes the amount of support work needed.
This is a smart or practical design that considers not just the end result but how to achieve the end result in the simplest way possible. Adjusting your design so you have fewer supports or so you have fewer supports in hard-to-reach places will make the post-processing much easier when it comes time to remove them.
In contrast, if you do not give much thought or planning to how your supports will figure in your print, you are certain to have supports embedded in places that are hard to access by hand or tool. Design should therefore be your first consideration if you want to print easy-to-remove supports.
How Do You Make 3D Supports Easier To Remove?
Aside from designing easy-to-remove supports, using dissolvable supports is the most efficient way to make supports easier to remove. Dissolvable supports are supports that dissolve in liquid. PVA for example dissolves when immersed in water. The advantage of using dissolvable supports is it eliminates the need for any cutting or breaking to remove the supports.
For example, you can print your 3D item in PLA, ABS, or whichever material you are using. Your supports can be printed in a water-soluble filament like PVA. After you are done printing, all you do to remove the supports is dip your print in water and watch the supports just melt away.
Dissolvable supports have one major downside. They can only be used on dual extruder printers. Fortunately, there are other solutions that reduce the difficulty of removing supports.
Tools are especially useful if your supports are in hard-to-reach places. A needle nose pliers for example can reach places where your hands or fingers cannot. Other tools that will come in handy are a small pocket knife, files, scrapers, and high-grit sandpaper.
Why Are My 3D Supports Hard To Remove?
Very often, using the wrong type of support structure will make removal harder than necessary. There are two main types of supports, namely lattice and tree supports. There are designs where one is more suitable than the other in terms of how easily it can be removed post-printing.
Lattice or linear supports are the most commonly used since they fit almost any project. These are straight columns that proceed from the print bed. While lattice supports hold up most of an overhang, they do have the disadvantage of being harder to remove.
Tree supports look like trees. They have a trunk from which branches sprout to support a print. Generally, tree supports are easier to remove but they have fewer contact points with the print which reduces their effectiveness in holding up overhangs and bridges. Source