After I realize the septic alarm was no longer working, I looked for a replacement.. I could not believe the price on such a simple circuit. I already had the float in the tank. It’s literally a buzzer, a switch and a button. they cost around $100 a cheap one is $70. So I decided to make one, all in it cost me under $20. Would be under $10 if you could buy individual buttons and beepers. I’m new to 3-D modeling and doing it for about a month and a half. I’ve been 3-D printing for almost 2 months. This is maybe my second or third functional design. But I decided to share it anyway. It uses all M3 hardware. I did share the parametric design on fusion 360. Please keep in mind this is the second thing I designed in that program or any CAD program for that matter, but I wanted to share it in case you had different hardware. I used a 12V 1.5amp power adapter from an old something I had, it was plenty of power to run 40 feet out to the yard where the tank is.

Items Used:

6 M3 threaded inserts

4 M3x25 up to M3x35 hex head screws 

2 M3X6 or M3x8

2 12mm toggle buttons  https://a.co/d/bYVwXL4

SFM-27 beeper   https://a.co/d/bm9WOsc

12v-24v power supply. https://a.co/d/3xSqwZX

Two. Wire nuts. 

Solder heat shrink tubing 

A few snips of wire 

Wiring is very simple the test button obviously only test the speaker. The off button was put there basically as a silence button. If requested, I can draw a diagram.