Tamper-proof screw for Blowtie/Duotight Regulator

“Tamper proof” adjustment screw for Duotight Blowtie/In-line regulator. Usually these come with yellow “buttefly” type screws, that can easily be bumped. Can be a pain if that happens, so this one can only be adjusted with a Philips-screwdriver. Kegland sells “tamper-proof” screws themselves, but wanted to see if I can design my own version and quickly print one.

Thread is M12.5x1.0, so I added a custom profile in Fusion based on a thread tolerance calculator. Printed in Polylight PETG with 0.12mm layer height. Worked out of the box with no issues and rly good fit. Depending on the filament used and your dimensional accuracy you might want to tweak a little with scaling in Bambu studio. I suggest do print once, and measure with a calliper.

I made 2 lengths. 12mm and 10mm. Just try which one suits best. Only difference is screw length.

Hope the model helps a few fellow homebrewers out ;-)

Dont change the seam settings. It should put the seam in the cut-out that runs vertical through the threads. This avoids thread issues due to the seam beeing placed all over the threads otherwise. (Since these devices use a diaphragm to control pressure, this screw doesn't need to be airtight.)