Inspired by pdavis41's DIY drop checker, https://www.plantedtank.net/forums/di...p-checker.html
I made one for myself, using his design with possibly a few differences. I don't want to step on his project, so I'm posting this on a new thread.
I had a piece of 3 inch wide, 1/8 inch or a little less thick acrylic scrap on hand, so I used it. I made all cuts with a utility knife, scoring the acrylic 3 or 4 times on one side, turning it over and scoring the other side right on top of the same mark. Then I just snapped it off. This leaves pretty good edges, but I used some 220 sandpaper on a wood block attached to my work bench, and rubbed each piece on that to even and smooth each edge. I glued it together with medium viscosity acrylic cement. Working with the tiny pieces was difficult, but I used generous amounts of cement to make sure I got good leak tight joints. Step by step went like:
1. Cut a strip of acrylic about 3 inches long, about 3/4 inches wide.
2. From that cut the 2 red and 2 blue pieces, so they are all the same width.
3. Glue the two red pieces together, and the two blue pieces together.
4. Rub the sides of these angle assemblies on sandpaper to get flat sides, with both assemblies the same width.
5. Cut a strip of acrylic about 3 inches long, wide enough to connect the red and blue angle assemblies as shown.
6. From that cut two equal length pieces to fit the red and blue angle assemblies as shown, leaving a gap as shown at the top of the blue angle assembly.
7. Glue the red angle assembly and the blue angle assembly to one of those two equal length pieces, purple, and let the glue set up.
8. Glue the second equal length piece on top of the assembly as shown. The front will be completely open.
9 If necessary, sand the open front of the assembly to get all edges to form a continuous flat surface around the outside.
10. Paint the face of the inside of the blue assembly with white nail polish and let dry.
11. Cut a strip of acrylic about 3 inches long with a width to match the glued assembly, so this becomes the window into the drop checker.
12. Measure the diameter of the groove in the suction cup stem, and drill two holes through the strip about one hole diameter apart, as shown. Use a file to remove material to make the opening an oval. Do a trial fit on the suction cup. If it won’t go into the hole, use a round file or sandpaper board to file the opening into a fatter oval to get more room. Continue this until the suction cup is installed. (green piece)
13. Glue the “window”/suction cup piece to the assembly, as shown, with the suction cup at the top facing as shown.
14. When glue is all dry, test for leaks by installing in a tank of water, with no water in the drop checker. After an hour, remove it carefully and verify that there is no water in the fluid chamber.