Snap-on Face Visor Build Instructions & Usage Guide

Author & Designer: Ken ChewDisinfection Guidelines: Phang Yuk YeeVisor Model: v2.0Document version: v1.0

Introduction

● The snap-on face visor/shield was designed based on feedback from the users, mostly frontline medical care workers and doctors faced with PPE* shortages

● The goal of the project was to design face to address the following requirement points○ Designed for reusability, ease of maintenance and sanitization, with less to no hard-to-reach nooks that

trap contamination○ Easy to install and use, with removable/adjustable front A4 transparent sheet orientation and height○ Able to be used in conjunction with prescription eyeglasses as well as masks/respirators (e.g. N95, FFP3)○ Avoid punching holes in the plastic sheets, a possible contamination entry point, and reduce manual work

of preparing the plastic sheets with a hole puncher○ Comfortable to be worn for long hours, without adding sponge which is easily contaminated and unable

to be sterilized effectively.○ Balanced with ease of printing with a range of 3d printer models and materials (PLA, PETG, ABS). ○ Optimized for smaller footprint for printing on small form factor home printers (200mm x 150mm beds) ○ Not significantly longer to print with comparable designs and size○ Options for protecting contamination from above as needed with a top cover component

● Models can be downloaded → HERE* PPE - Personal Protective Equipment

Disclaimer

● These visors are to be produced by volunteers offered in good faith and the design is open sourced to meet the urgent need among frontline health workers and caregivers during COVID 19 crisis. The design can be used freely but NOT for profit

● These visors have not yet been certified. Until certification is received, we kindly request that you send one visor to your hospital’s head of infection control for review.

● The models presented here will continuously evolve based on feedback and new needs, and the actual models downloaded may differ from the illustrations and photos included in this guide

Snap-On Visor Design Features Version: 2.0

179 mm

145 mm

Flexible forehead rest

Easy separating but secure gap for clipping

acetate clear sheet

Mini tab for better

bed adhesion

Hooks for elastic band for tighter fit

- Clear sheet thickness of 0.2mm and 0.3mm were tested successfully

- Thinner and lighter plastic sheet is preferable to maintain a good curve and fit on face

Retainer clip with curved groove for gripping the plastic sheet

Snap-On Top Cover Compatible with Visor v2.0

Top cover can be used in higher risk application where possible contamination can come from above, however, due to fitting constraints, the design is yet to offer full coverage

Printing Instructions

Reference Printer: CEL Robox DualPrinter Specs : LinkBuild size : 210 x 150 x 100mm

Reference Print Settings

Model downloads Download Link

Materials ABS, PETG, PLA

Layer Height Optimized for 0.3mm

Nozzle Size 0.4mm

Infill 20% baselineIncrease % for higher stiffness of the visor arms

Support Not Needed

1st Layer SpeedNormal Printing Speed

8mm/s60mm/s

Time to Print ~45min Visor~25min Top Cover

Material Amount Used ~18g Visor~7g Top Cover

Plastic Sheet Size A4 (297 x 210mm)Thickness 0.15 - 0.25mm

Material Notes (Detailed Comparison Table Link Here)

Material Pros Cons

PLA ● Low Cost, Most common home printing material● Easy to print, no heated bed required● Not produced from fossil fuel, biodegradable under industrial

composting conditions

● Low service temp of 52C. WIll deform from 60C onwards.● Hard and less flexible. Brittle and breakage prone if filament used was

exposed to moisture for too long, or been on the shelf > 3 years

PETG ● Higher service temp of 73C● High strength● Water, chemical, impact, and fatigue resistant● Less risk of skin allergy with long exposure● Minor warping and shrinking when cooled

● Heated bed required (75-90C)● Can be tricky to tune and print and depending on filament quality, can

be prone to nozzle jamming● Higher cost than PLA● Recyclable like PET but still produced from fossil fuel● May emit fumes during printing

ABS ● Highest service temp of 98C● High strength● More flexible and impact/fatigue resistant than PETG●

● Higher temp heated bed required (95-110C)● Higher cost than PLA● Fumes are toxic (Extractor needed) ● High shrinkage and warping when cooling. Hard to adhere to bed● There are reported skin allergic reaction to ABS with prolonged

exposure

Usage InstructionsInstalling Clear Sheet and Visor Usage Sample

Prepare MaterialsUse an A4 0.2mm / 0.3mm thick acetate or clear binding sheet

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Spread the visor arms outwards and the snap-on gap will be visible

Separate the retainer upwards

Insert the transparent sheet and slide into one end of the retainer gap.Slowly pull the sheet across the retainer until the entire width of the A4 sheet has passed through.Allow more plastic sheet to the top for easier installation. You can adjust it later.

Adjust the plastic height above the visor to your preference. Recommend to have at least 2 cm plastic sheet above the visor

Spread the visor arms again and this time align the outer retainer with the inner band.Return the visor to its original position.It might be good to roll the lower plastic sheet inwards to achieve a better curvature to fit your face.

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Completed Assembly

Pro Tip:

If you find it hard to keep the film in position, make it easier to lock in the visor groove by folding a line/crease along the plastic sheet.

Align the fold line against the visor retaining groove.

Position of groove

Optional StepsInstalling the Top Visor Cover and Optional Elastic Band

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Pair the top cover with the visor

Align the retention clips of the top cover with the visor

Completed installation

Bottom View

Visor with top cover and installed plastic sheet

Optional elastic band if fit is too loose

View from above when worn

Note:

Please remove the top visor and sanitize separately

Depending on procedure, the elastic band should be disposed of during each sanitizing cycle

Disinfection GuidelinesFor One Person Disinfecting Multiple Face Visors

Printable A4 Disinfection Guidelines can be downloaded → KEN TO ADD