Adding Supports (that peel off)
Plastic extrusion printing works like a hot glue gun - the material is very flexible when it extrudes out, and will sag until it lands something (a support). This means you need a backing material on which to print. On the first layer of a part, the print bed acts as the backing material. But, what if you want to print an arch, or a flange on a part that is otherwise "unsupported"? As the name implies, support material provides the backing to hold the extruded plastic in place while you print. Since these supports are only there to help during printing (and not something you want to keep on the part) you can peel them off later.
Orient parts to be flat on the print bed.
Cups should face up (to minimize supports).
The Mark One is capable of printing overhangs up to 45 degrees without supports.
When supports are on, scaffolding will be applied to any overhang over approximately 40 degrees from vertical.
Orient part to sit flat on the print bed (as if you set them on the bed). Any angle gap you leave will be filled in with peel-off support, wasting time and material.
- Part oriented 10 degrees above the print bed. People usually catch this.
- Watch out for parts that are "2 degrees" off the bed. Some parts may appear to be lying flat against the bed but are actually slightly raised or slanted.
Note: if you suspect a part is not lying flat on the bed, enter the 'Internal View' of the part and select the '2D' view to check the first few layers. If the 2D view of these first layers displays the expected cross section of the part, then the part is flat.
- Internal View of 10 degree angled part (supports hidden)
- Printing this without supports will cause the print to fail.
- Internal view of 10 degree part with supports shown.
- Notice all the wasted material and print time.
Orient Prints to Hold Water
Since peeling off supports takes time, and uses more material, it's best to orient parts to minimize the use of support structures.
The part below imports with the cavity face down. This entire cavity will need to be filled in with supports. Alternatively, we can rotate the part 180 degrees in X, as shown in the second picture, and avoid filling the part with supports. Eliminating these supports will cut 4 hours off the print time, and save 60% of the material.
- Bad orientation.
- Internal cavity will be filled with supports.
- Correct Orientation
- Internal cavity supported by print bed (no peel-off supports needed)
No supports up to 45 degrees
When printing a slight overhang, up to 45 degrees, the extruded material will be sufficiently constrained without supports. This means you can print complex shapes, like this turbine, without supports.
- No support needed with overhangs up to 45 degrees.
- Incorrect orientation. If rotated upside down, the part is filled with supports, wasting time and material.
- Incorrect orientation. Shown with supports suppressed.
Adding Support Material
Here's an example of a part with an unsupported arch (hole) on the right hand side. Since the hole is small, it will print with some sag on the top layers of the hole. For the best fidelity, turn supports on.
- Part overview, showing arch (hole) on right hand side.
- Note the hole has no supports in this view
- The top layers of the hole will sag down a little. This can be cleaned with a knife after printing, or you can use supports.
- Note the thin supports in the hole now. They will support the top layers of the arch as the plastic extrudes, limiting the sag, and providing better fidelity for the shape of the hole.
- These supports will be peeled off after printing with a pair of needle-nose pliers.