If you like to make your own PCBs at home, you going to need something to hold your PBCs when they are submerged in acid. And a tank. This is my solution, you need only this:

3D printer

- Or someone to print this for you. I used white PLA, holds up against acid prety well.

SuperGlue - Some parts need to be glued.

Screws - 2x M3x15, 1x M3x10

Rubber band - Choise is up to you. 10cm shoud be long enoughth.

Optional: Small motor with weight from old phone. 4 or 5 mm diameter. Tank, more at the end.

Supplies

Screws M3x15, M3x10

Rubber band

3D printed parts

SuperGlue

Step 1: 3D Prints and Assembly

Parts D and E need to be printed twice, from every other is only one needed.

Assembly can bee seen on pictures. We start with pushing part A through F. Put parts B, D and E together with M3x15 screws and then push AF through B. I don't know what to write here, pics are kinda self-explanatory. Then you put the rubber band in the groove in part A, put part C over it. You can glue A and C together, but theres a hole for a screw (M3x10) on the side to fix it, so when the rubber band snaps, you can easy replace it. Parts E are then glued to G. Wind the rubber band up around parts E, like in picture.

Optional: Motor is glued into part C (see pic). The idea is to shake the slag off the PCB int the etching process. I used 4mm motor, but if you use 5mm diemeter, you have to fix it higher. Part C has a 4mm groove that goes into 5mm. That 5mm part is for weight of the 4mm motor, but can be used fot 5mm motor body with weight sticking out.

Pro-Tip: SuperGlue hardens superfast if you sprinkle it with baking soda.

Step 2: You Are Done!

Congratulations. You are done!

Clamp your PCB in it, put it on the tank. Etche like your life depends on it. Hope someone finds this clamp usefull.

Bonus: Tank for acid - This instructable is about the PCB clip, but you will need this, so:

Only three dimensions must be respected: Glass needs to be 3mm thick, inner sides of glass need to be 20mm apart and depth has to be 210mm. This is due the "clip" (part G) hodling it to glass and part D length. I ordered mine from a guy that makes fishtanks. Was not expensive, because it holds only 1L of fluid.