Introduction: Contact Shape Comparison of Support Structures in SLA/DLP/LCD 3D Printing


3D Model: Siperman

Resin: LCD Rigid Resin GS-B11

Slicer: ChiTuBox V1.5.0

Model Source:

In ChiTuBox, there is a related parameter about support tips called "contact shape". You can choose "none" shape or "shepre" shape as shown below. Now let’s test the effect of these two shapes on the support removal and the surface quality of the object.

Step 1: "shepre" Shape

First, let’s deal with the "shepre" shape (label as No.1). According to the last test (Improve Surface Quality in 3D Printing by Optimizing Part Orientation), we put the sipderman in ChiTubox which form a certain angle with the vertical plane as 30 degrees to receive relatively good surface quality. The support structures are automatically generated by ChiTuBox, but then we manually adjust some. To ensure successful 3d printing and show how contact shapes affect support removal and surface quality, a little more supports have been added.

Although the model was been hollowed out, the head of the model is still large and heavy. So several parameter values were increased on the basis of the default ones. The specific parameters are set as follows: "shepre" shape, 1mm contact diameter, 0.5mm contact depth, 0.6mm upper diameter. As for the rigid resin, the number of the bottom layer is increased to 5 layers. Also, the exposure time is added to 9 seconds and bottom exposure time is 50 seconds.

Step 2: "none" Shape

Then let’s shift to "none" shape (label as No.2). Except "contact shape" parameter, others are no different.

Step 3: Rinsing the Objects

After 3D printing, the next step is rinsing the object. When rinsing No.1, we use the totally new isopropyl alcohol. But when it’s the turn of No.2, the isopropyl alcohol is polluted by yellow resin. So the No.2 is dyed into buff. It might be a blessing in disguise because now we can clearly distinguish No.2 from No.1. The support structures of No.2 are generated integrally while some parts of No.1 are breaked.

Left: No.1 ("shepre" shape) Right: No.1 ("none" shape)

Step 4: Removing Support Structures

When removing the support structures, we find it’s much easier to remove No.1. In other words, No.2 is more stable than No.1 in terms of the strength of support structures. After removing the support structures, the support residues of No.1 left on the model surface are more obvious than No.2 as shown below.

Left: No.1 ("shepre" shape) Right: No.1 ("none" shape)

Step 5: Wet Sanding

Electric sander pen is used for polishing which includes various accessories to switch. Here we use grinding wheel and fine sandpaper roll.

Although No.1 left a lot of residues, they are much easier to be polished than you might think because they are raised. After polishing, the surface quality of No.1 is better than that of No.2. However, it can be caused by dyeing which will inevitably look yellow and white after polishing.

Left: No.1 ("shepre" shape) Right: No.1 ("none" shape)

Step 6: Surface Quality

Besides, there are remarkable pot holes on the surface of No.2. Because the rigid resin is relatively brittle and cutting will easily leave pot holes. But with shperes on the surface, it’s much easier to protect the surface when removing the supports.

Step 7: The Comparison Results

1. The support structures of “shepre" shape is easier to remove than that of "none" shape.

2. The support structures of “none " shape is stronger than that of " shepre" shape.

3. After removing the supports, the support residues left on “shepre" shape surface are more obvious than that of "none" shape.

4. Pot holes on the surface of "none" shape are more remarkable than that of “shepre" shape.

5. The surface quality of “shepre" shape is better than that of "none" shape.

PS: The spiderman looks even cuter if it is colored.