Graf tank lid key

thingiverse

This is the key I made to open the lid of my Graf wastewater treatment plant tank. First use the 17mm hex socket part to turn the bolt then insert the wing of the key in the slot by the bolt and lever open the lid. I've been using it to make occasional checks of the tank for the last 9 months and it's been fine. I made it using PETG and it has been plenty strong enough. I used a bright orange so I can see it easily when I put it down. I don't plan on dropping it in the tank but if that happened it would stand out against the other floaters:( in the tank. I originally designed it with two hex socket ends so that I could still use it if I damaged one end (graf_tank_key_v2.stl). This version needs support when printed. I've included a version (graf_tank_key_v3.stl) that prints without support but only has one hex socket end. There is a small hole in the side of the tool if you want to add a short cord for hanging it up etc..