For general information, please visit the UCSF 3D Shield Project main page.
This repository contains the complete list of all versions of the UCSF 3D Shield and their updates, as well as frequently asked questions regarding stacking of 3D models and tips for 3D printing.
|Model A||Model B||Model C|
|Description||The original model, optimized for printing speed. The sheet holder pegs have been optimized so that they do not require supports.||Model B keeps the shield closer to the face than Model A. We have opened up the radius of curvature to fit slightly larger heads.||As some areas are requesting a higher level of protection, Model C is a version of model A that has an added protection brim. It can be stacked 3x.|
|Version History||Av1.0: original model.|
Av1.1: optimized sheet holder pegs that don’t require supports during stacked printing.
Av1.2: new version with optimized rubber band holder attachments.
Av1.2 plain: version of model without the UCSF logo.
Av1.21 plain: one of the shield holding pegs fixed for improved printing on Taz 6.
Av1.3: changes to the band holder allow stacked files of this version to separate easier.
CvXL1.0: increased distance from the forehead to the shield to accommodate users wearing large goggles.
|Links to STL Files||Av1.0|
Av1.0 2x nested
Av1.0 3x nested
Editing the UCSF Face Shield Model(s)
We understand that various needs may arise which require direct editing of the UCSF face shield 3D model. Below is a list of shield frame models available in .STEP file format for editing in CAD softwares. All .STEP files provided are intended for non-commercial use.
All files are licensed under a Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
3D Printing Tips
For PETG, the settings we use are a heated bed of 85-90C on the Prusa MK3, and 60C on the Lulzbot Taz 6. Print temperatures are from 240-260C. As PETG has a “stickier” consistency than PLA, it will stick to the nozzle, so a slower first layer is very important. We run our first layer at 20mm/s and layer heights of 0.3mm to maximize print throughput. Our volumetric flow rate on the Prusa is set to 8 mm^3/s. We have run it at 11 mm^3/sec and it works with reduced reliability. The .gcode provided from the Prusa website runs PETG even faster, but the printer really needs to be tuned up. On the Lulzbot, we are using default settings for the IC3D PETG profile, we find that it prints a little slower than the Prusa, even with a 0.35mm layer height, but works reliably.
For adhesion, we use gluesticks on the smooth PEI. For the textured bed, we don’t use anything. PETG requires a more squished down first layer than PLA. On our Stratasys F370, we are running in draft mode, with a layer height of 0.0100″ which is a 0.254mm layer height. To go to a taller layer height, you can’t print in draft mode and GrabCad generates excessive supports. With the Stratasys, you can fill the build volume with 48 models takes up 73cu in of material and 4.58cu in of supports. With a print time of 31 hours. The F370 doesn’t support PETG and we need to print in ABS or ASA.
Stacking Multiple Models
About Stacked Prints
“Stacking” refers to layering multiple 3D models within the same 3D print job with the help of support enforcers. Stacked prints improve printing efficiency and can be removed individually once the print is finished. As 3D printer build volumes vary, printing singular or nested versions of any model on your printer of choice is recommended before printing the stacked versions.
We have developed stacked STLs that are optimized for printing at 0.3mm layer heights. We don’t see much benefit for multi-day prints, as our printers will be attended to daily.
*16x maxes out the print height of the Prusa and is an overnight print.
Frequently Asked Questions
What 3D printers are you using to print the face shield frames?
We are primarily using a combination of Prusa MK3 and Lulzbot Taz 6 printers. Additionally, we are using the Stratasys F370. If you are using these printers, please see the above section, 3D Printing Tips, for more information on printer settings.
I don’t have PETG material/my printer doesn’t support PETG. Can I print with a different material like ABS?
I need to edit the file/ make some dimensional changes. Could I obtain the original 3D model?
We have made Model A (v1.2) available as an editable .STEP file under Creative Commons licensing. Please refer to the 3D Models section above for more details.
I’m unable to print the stacked files successfully on my printer/get an error in my slicing software. Any tips?
You will want to use a support enforcer in Prusaslicer or other slicing software of choice. You can do this by making a tiny cylinder or cube then resizing it so that it is vertically tall. Then this shape can be added where it intersects all the models. The empty layers error should go away once this is accomplished successfully.
I don’t have transparency sheets of 8.5”x11” in. size and 7 mil thickness. Will it still work?
That is OK. Transparency film of this size and thickness will fit Model A face shields best, but if you are not able to acquire material of the exact size or thickness you may refer to other smaller (Model B) or larger (Model C) models of the face shield.
For general inquiries or to request face shields, please contact firstname.lastname@example.org