Labradar Recoil Sensor

[centerfire]

FWIW if using the adafruit vibration sensor switches no capacitor or resistor has been needed in my experience. I've been using mine that way for about 20 months.
https://www.digikey.com/catalog/en/partg...ches/68699

I prefer the medium switch, I can trigger the fast with just hand tremor. Dropping the bolt on any semi will trigger it, so I do that first then arm the Labradar.

I use a loop of shock-cord with a plastic cord lock to attach the sensor. I typically will put it on the scope tube or bell but I can attach it anywhere; hand guard, bipod etc.

For a simple enclosure and to ease assembly I used a 3.5mm 3 pole stereo male plug connector. It is still fine soldering but a heck of a lot easier than going wire to wire and it makes for a pretty sturdy package.
It also allows rapid changing of the switches if you wish to have one of each sensitivity for different tasks (fast for air gun, slow for a .50 etc.).

This all being said my time is valuable enough to me I wouldn't make them and sell them for what https://pietrecoiltrigger.com/ charges. I had all the equipment and components on hand except the switches so it was an inexpensive project for me to try.

EDIT:
One other point on why I arm after closing the bolt. As Klem noted a false trigger can give a "failed to track projectile" error. That one is no big deal, BUT, it can also give a random velocity reading as well. That one is a big deal if you forget where in a string it happened and don't delete it or delete the wrong shot. Piet has video of this issue on his site.

I've had the Piet recoil switch for two years. The false readings are easily distinguishable by the large velocity discrepancy. You can adjust the sensitivity of the LabRadar to reduce the false readings too.