SparkVent2 Ventilator Valve Cam Spark Vent 2

thingiverse

WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! WARNING! Be advised that this ventilator is a high-risk device and has not been tested or approved by any regulatory agency. If you choose to build it and use it, you do so at your own risk and the risk of those around you. Understand that these risks are enormous and should only consider building or using it when all other options have failed. The Sparkvent 2 Ventilator is a simple pinch tube air valve system powered by a cam for an experimental Covid-19 ventilator. For more details, visit these links: https://github.com/SparkVent/TheSparkVent http://sparkvent.org https://www.youtube.com/watch?v=2_yuuIKCDco&feature=youtu.be https://vimeo.com/405322505 The goal of this ventilator is to be as simple and cost-effective as possible without using expensive components like solenoid valves or electronics. The main component of the valve system is a silicone tube with an outer diameter of 14mm and a wall thickness of 2.6mm. When pinched, it can't be blown through for diameters of 4.2mm or less. I've used a 3.5mm diameter in the design to account for wear and deflection. UPDATE: The motor gearbox is severely impacted when run at low speeds and won't last. I'll change the drive configuration to use the pulley. Tips: 1. Don't run a PLA cam against a PLA follower, as friction will be high. 2. ABS for the cam and PLA for the followers work fine, but PLA for the followers may deform if left in a hot environment under load. 3. When assembling the cam and bearings, don't tighten too much, or it'll cause deformation of the print and bearing wobble. 4. Print solid to ensure safety. 5. The followers are tapered in width, so lay them flat when printing. 6. This mechanism should be screwed into a solid structure, not plywood. 7. Use a 5mm rod for the pin, or an M6 bolt if you need to drill it out. 8. Glue the bottom pinch point in place after verifying the cam valves are working properly. 9. Lightly sand the parts that pinch the silicon tube with wet and dry paper to make it smooth. 10. Most of the time, the motor drives the cam; for a brief moment, the cam drives the motor. Materials: - As shown in the kit photo. - I've included a pulley wheel in case you can't source a geared motor like mine (https://www.jaycar.com.au/36rpm-12vdc-reversible-gearhead-motor/p/YG2734). - M8 bolt, minimum 100mm long without the pulley or 125mm with it. - Skateboard bearings used (608 - 8mm ID, 22mm OD, 7mm wide).