Lithopane filament calibration tool

thingiverse

Lithopanes are incredibly enjoyable to create with a 3D printer, however different filaments and colors of filament allow varying amounts of light to pass through and can impact the available steps to produce the image unless the ideal maximum thickness and step size is carefully selected. This test piece allows calibration of the filament thickness used to create lithophanes, such as those produced by the Customizer at http://www.thingiverse.com/apps/customizer/run?thing_id=74322. The calibration wheel features 30 steps from 0.1mm to 3mm in increments of 0.1mm, providing adequate coverage for most filaments. To use this test piece, print it with the filament you wish to calibrate using 100% infill at a 0.1mm z-axis resolution. If the maximum thickness is not sufficient, simply scale the design in your slicer software. When printed, hold the lithopane up to a typical light source and count the steps from the lowest to where it becomes difficult to distinguish between two steps. Multiply the last step number by 0.1 to determine the required filament thickness for your black level (adjust for any scaling as necessary). The resolution of your z-step size will likely be limited, with a general rule being that more is better. If your black level is set at 1mm and your printer can only achieve 0.1mm steps, you will be capped at 10 grey levels for your image, which is relatively few. Filaments with lighter colors can potentially reach up to 3-4mm in black level thickness, enabling the production of 30 or more grey levels using a z-step size of 0.1mm. If your printer can print at 0.05mm steps, you can achieve over 60 grey levels (theoretically, although achieving this resolution may be challenging); this should yield excellent lithophanes. Considering these capabilities, it is feasible to develop a dedicated lithopane PLA filament that maximizes the production of high-quality images. I used http://www.thingiverse.com/thing:74322 to create my own Mona Lisa prints at 2mm maximum thickness for the initial print and calibrated 3mm thickness for the second; personally, I found the first print 'softer' and perhaps closer to the original. I designed this test piece in Sketchup and minimized its size (35x35mm) so that it can be easily used as a keychain without affecting the results for larger prints. The Mona Lisa designs were also 35x35mm. Printer Settings: - Brand: Printrbot - Model: Simple Black - Rafts: Does Not Apply - Supports: None - Resolution: 0.1mm - Infill: 100% - Notes: I used Simply3D and faberdashery PLA, as well as 3dom Ingeo PLA all with a 1.75mm diameter