I've been experimenting for some time on how to create 3D printable check valves. This check valve utilizes a silicone disc and ball. This silicone piece is inserted mid-print, minimizing the chances of air escaping in other spots. Once fully printed, the silicone part is put in a sprung position, allowing it to be pushed by air in one direction but not the other.
- PLA or ABS
- Ecoflex 00-30 Silicone
- 3D printer
- Thin screwdriver
- Fine-tipped tweezers
- Flush snips
Step 1: Casting the Check
Mix some Ecoflex 00-30 silicone in the cup with the spoon. Ecoflex is a 1A:1B silicone, meaning you should mix an equal amount from each bottle. You do not need much for this project.
Step 2: Demolding the Check
After the Ecoflex has cured for about 4 hours, peel the edges of the disc part of the check and pull it out gently.
Step 3: Inserting the Check
Print ValveBody_supported.stl (or ValveBody.stl if you want to use your own supports) the same way as the mold. (This is to reduce cracks so air does not escape). Pause the print before the top fillet starts. If you are printing at .2mm layer, this should be around layer 190. If your printer does not automatically move it's head out of the way when paused, move it manually. Use the thin screwdriver to clear the hole on the inside of the valve of any stringing or blobbing. Insert the tail of the check into the hole and lower down the whole check. Press down the disc of the check with the screwdriver a bit. If you moved your printer's head manually, move it back now. Continue the print to completion.
Step 4: Finishing Touches
Use the fine-tipped tweezers to grip the the tip of the tail of the check. Pull it as far out as you can and snip it with the flush snips. Be careful to not snip the ball.
Step 5: Use
To use the check valve, connect 1/4" tubing to it's ports. An arrow shows which way the air flows.