Telescope Counterweight

A telescope counterweight. Fits 20mm shaft.

With lead shot it will be about 4Kg (I only had enough shot for about 3.1Kg). You can fit two on most mounts I've seen. Prints with no supports. Internal ribs for strength at the bottom. Filleted edges inside. Beveled outside (because it prints nicer). Recommend heat resistant and strong filament with 5 to 7 perimeters, maybe even solid infill (it's a weight, right). I used PC-CF.

Bill of materials: 1/4-20 2" bolt (stainless if you can). If you can spend a few minutes to round the end it will probably hold better and mark the shaft less. 1/4-20 nylock nut 4 M3 Self Tapping Screws like https://www.amazon.com/dp/B0CDBCJBYK, any length up to around 30mm. You can probably get regular M3 machine screws to thread in and work, since the lid is not load bearing. A weight like lead shot, BBs, or even sand.

Put a piece of tape over the nut after inserting it, so shot and epoxy don't get in. Mix the lead shot with a little epoxy if you don't want it to shift, or if a partial fill top up with expanding foam or RTV silicone. I used #9 lead shot and 30 minute Bob Smith Ind. epoxy. Optionally a little super glue or epoxy on the lid before screwing it down. When installing it on mount, lid goes up.

Tighten with a wrench or print a knob. I did not design one since there are plenty out there. I like these https://www.printables.com/model/610798-14-20-and-516-18-knob-pack The 40mm size seemed a good fit.