Electromagnetic Chronograph

Warning, before you test this device make sure that you protect your sound card from voltage spikes or use a disposable device.

Use thin copper wire to make coils and connect it to a sound card that supports stereo recording. In Audacity you can record the data collected from the device as you shoot magnetic objects through the coils. Set the recording device's gain to minimum for initial tests, because you can damage it if you have too fast object, too strong magnet or too many windings

After you do some testing, you can experiment with the number of windings and gain settings to get desired results.

Distance between center points of coils= 200mm

I built mine with 100 windings and I can recommend that for good and relatively secure start.
When it comes to printing materials I recommend PETG or ABS, whatever is cheaper.

It works well for blowguns, bows, airguns and other devices that shoot darts that can be magnetized. It might work with firearms, but you would need magnetic bullets, maybe armor piercing with iron core or something like that. I am also curious if the heat will ruin the magnetic properties of the bullet or not. I leave that for you to test. Let me know if you have tested something like that.

It is also a good project for programmers. If you can automate the measurement process, it would make the life way easier.

Please do not re-upload STL or any other mesh version of this project. I upload STEP only, because I want it to be easily editable. Do not poison the internet. For commercial use contact me and I am sure that we can build something cool out of it. Other than that do whatever you like as long as you mention me as the author of the model.