3D Printing

3D Skull model

3D Skull model

Our figures range in size from 6″ – 24″ tall, and use 6mm – 12mm eyes so now that we have a final 3D Master Skull Model it can be copied and resized to suit our needs.

We decided to print (3) Models – (1) Head [2″H] and (2) Skulls – Small [1.75″H] Medium [2 3/8″H]. The model objects can be sized within the printer software but we needed proportional holes at the base of the head for neck support so the Master files were pre-sized in the 3D modeling program, saved as separate .stl files and imported into the printer software work area.

NOTE: We have a XYZprinter DaVinci 1.0 (1 colour, ABS filament) so can only provide information and steps pertaining to this printer.

Prepare for Printing

The 3D Printer should be calibrated before printing to ensure a good print. There is an app available on Amazon for the XYZprint DaVinci Calibrator which has been a very helpful and time saving tool in giving you a set of numbers to begin calibrating.

Calibration app

Apply a thin coat of UHU glue to the Print Bed, this helps the object(s) to stay in place during the printing process, now you are ready to begin the next step.

Before the objects can be printed they need be Sliced. Object Slicing is dividing (slicing) a 3D model into hundreds or thousands of horizontal layers (think of a deli slicer), then the file is digitally uploaded to the 3D printer where it “reads” every slice and creates a three dimensional object, printing layer by layer with a thin extrusion of (very hot) melted plastic.

Slicing time is determined by the Print settings – this is where you indicate the QUALITY: (normal-good-excellent), INFILL DENSITY: (hollow-low 10%-solid 90%), SHELL LAYERS: (thin 1-nomal 2-thick 3), RAFT (increases contact on the printer bed) or SUPPORTS (used for structural strength, if the object has projections or uneven base), and LAYER HEIGHT: (0.1mm-0.2mm-0.3mm).

Higher quality files will take longer, most files will print very well using the Standard/Good resolution. If the Slicing time seems to be extraordinarily long or ‘hang’ then check if the object density mesh is too high, it will need to be reduced in Meshmixer.

For this project we chose the following Print settings:
QUALITY: Good | MATERIAL: ABS | INFILL DENSITY: Medium (25%)
INFILL TYPE: Rectilinear | SHELLS: Thick (3 layer)  |  LAYER HEIGHT: 0.2mm
SPEED: Standard | RAFT: Yes | SUPPORTS: Low (this setting is easier to remove the supports later)

The Slicing time took about 30 minutes before sending to the Printer.

It’s Printing Time!

All is good and ready to go! The object has been prepared and uploaded to the Printer and now you just have to let it do it’s thing. The estimated Printing time is 4 ½ hours, even if it starts out looking good, it is best to observe the beginning stage (30 minutes to 1 hour) and then check on the process from time to time in case something goes awry, like the object does not stick to the Print Bed, or a plugged nozzle.

The extra pieces on the Head and Skulls (Small-Medium) around the eyes and mouth are the Supports which will be removed as well as the Raft piece at the base. The Layer Height 0.2mm setting creates fine ridges on the models which is okay if used as an internal structure but the Skull face area is going to be used as a base to sculpt over.

Cold Vapor Bath

The extra pieces on the Head and Skulls (Small-Medium) around the eyes and mouth are the Supports which will be removed as well as the Raft piece at the base. The Layer Height 0.2mm setting creates fine ridges on the models which is okay if used as an internal structure but the Skull face area is going to be used as a base to sculpt over.

The main Skull will be part of the finished Head so the ridges will need to be smoothed, this is done by placing the Skull in a Cold Vapor Bath – outside or in a well ventilated area.

Materials needed: Empty Metal Can with Lid (quart) that will easily cover the Model, Magnets, Paper towels, Timer, Acetone, base to hold the Model (or if the base is flat, place on aluminum foil so it does not stick to the lid).

Cut the Paper towels to fit the inside of the Can, attach with Magnets. Place the Model in the center of Can Lid – there needs to be room around the Model, do not let it touch the Can walls.

Using a Paper cup measure out about 1 Tablespoon of Acetone and pour onto the Paper towels, rotating the can – Add more Acetone as needed, the Paper towels should be wet but not saturated (the can will feel cold to touch). Place the Can over the Model – do not close too tight, the Can will be opened a few times to check on the progress.

Set a Timer for 30 minutes. Keep checking on the Model every 30 minutes until the desired results are achieved – add more Acetone if the Paper towels look too dry.

Remove the Model from the Vapor Bath and set aside to dry for a day, thin semi-transparent areas (ears) will look solid when completely dry. NOTE: the surface it is still soft and slightly pliable so small imperfections can be smoothed out further with metal tools.

Finished Medium Skull [2 3/8″H] – Acetone Cold vapor bath time = 2 hours


Created with the Support of Creative Pinellas and the Pinellas County Board of County Commissioners;
the City of St. Petersburg Office of Cultural Affairs and the St. Petersburg Art Alliance.
2016-10-27T16:59:40+00:00 October 26th, 2016|Categories: News-Blog, Techniques, Video, WIP|Tags: , |