Blower Materials List

In return for receiving access to the information contained in this document from us, the reader acknowledges and agrees to the following:

1. We are a group of broadly experienced engineering volunteers working on this crisis emergency. While we are working closely with multiple front-line physicians, our engineering team is not specifically trained in infectious disease control.

2. Our role is limited to advancing the distribution of potentially helpful designs, tutorials, and information, compiled and disseminated from a range of sources, without being able to fully evaluate the efficacy or safety of all such content.

3. You release and agree not to sue us or people working with us on disseminating the information in this document, from all present and future claims that may be made by you, your family, estate, heirs, or assigns for property damage, personal injury, or wrongful death arising out of or in connection with your participation in any way with the activities suggested by this document.

This is the Materials List for the Open-Mask Model A PAPR blower.

A note about the fasteners: to keep parts count and costs down, all but two of the fasteners are the same length. If you have the budget you may want to use more appropriate fasteners. Part numbers are given for both Metric and Imperial for your convenience – you don’t need to purchase both.

Note: All devices are rapid emergency Prototypes that are not FDA approved


3D Printable Parts
Image Description Download
Driver Mount STL
Belt Loop STL
Air Box STL
Air box mount.
Note: You’ll need to print two of these.
Battery Holder STL
Fan Spacer STL
Open Mask Nozzle STL
Optional Drill Template – Top Right STL
Optional Drill Template – Top Left STL
Optional Drill Template – Side Left STL
Optional Drill Template – Front STL
Optional Drill Template – Back Right STL
Optional Drill Template – Back Left STL
Cutting and Drilling Drawings
Description Download
Enclosure Back PDF
Enclosure Front PDF
Gasket Template PDF
Quantity Description
8 M4 x 0.70 mm Thread, 16mm Long Stainless Steel Button Head Hex Drive Screws McMaster
2 M4 x 0.7 mm Thread, 16 mm Long Stainless Steel Hex Drive Flat Head Screws McMaster
10 M4 x 0.7 mm Thread Stainless Steel Nylon-Insert Locknuts McMaster
10 M4 Stainless Steel Washer McMaster


Quantity Description
8 8-32 Thread Size, 3/4″ Long Stainless Steel Button Head Hex Drive Screws McMaster
2 8-32 Thread Size, 5/8″ Long Stainless Steel Hex Drive Flat Head Screw McMaster
10 8-32 Thread Size Stainless Steel Nylon-Insert Locknut McMaster
10 Number 8 Screw Size Stainless Steel Washer McMaster
Image Description
1 Blower – CUI Devices CBM-979533B-168 Digikey, Mouser, onlinecomponents
1 Talentcell Rechargeable 6000mAh Li-Ion Battery Pack Amazon
2 2.1mm Female Right-Angle DC Power Plugs
Note: You’ll need two of these.
Note: Other options include: This or this
1 DC Power Jack Male 2.1mm x 5.5mm Panel Mount
Note: Other options include: This
Jameco, Banggood
1 3a 12v Motor/Fan speed controller. The one we use measures 32mm x 50mm Banggood
1 Hammond Manufacturing PR-1375 Digilink, Mouser
Other Things
Quantity Description
1 Belt – 2″ nylon or web belt available at many places.
Note: Be aware that there’s not much room between the PAPR and the belt loop.
here, here, here, here, here, here, here
1 HEPA Filter – 86889
Caution: Many cheap filters use fiberglass strands to filter the air. Kenmore claims their filters are fiberglass free but we have not been able to confirm. UPDATE: Kenmore rep confirms their filters are fiberglass free.
1 Silicone Caulk –  Gasket Maker Sealer McMaster
3ft Blo-R-Vac Very Flexible Duct Hose for Fumes – Clear PVC, 1-1/4″ ID, 1-1/2″ OD McMaster
2ft Food-Grade Super-Cushioning Foam Sheet Polyethylene, 54″ Wide, 1/8″ Thickness McMaster
4 Cable Zip Ties at least 100mm (4″) long. McMaster, Amazon, Cable Ties and More
  • 3D Printer
  • Drill and Drill Bits – Metric 4.5mm or Imperial 11/64″
  • Screw Driver
  • Wrench
  • Hex Keys
  • Soldering Iron and Solder
  • Heat Shrink
  • 22 AWG wire. 120mm (5″) red and black.