Replacement endcaps for cheap RC screwdrivers

Replace the stock plastic endcap on cheap RC screwdrivers with a simple cap that can be color coded or a thumb twirler cap. Uses a single M3 socket head screw to attach.

I may have used a hammer on the end of my cheap RC screwdrivers, and may have chipped the stock plastic cap. (I admit nothing) I was going to print a simple replacement, but then realized that I could add a thumb button that spins which allows the use of a finger on top of the button to hold the screwdriver in place while turning it, or hold the button in my palm. Basically, make it like fancier screwdrivers, while also having the ability to color code it by size.

My screwdrivers have the name “FPVERA” on them, but this is the usual generic stuff that's usually available under many, many different random names, so the odds are good that these will fit if you've got ones that look the same.

Uses (1) 3mm socket head screw to attach the thumb button, can be as short as an M3x6. Longer works but will just be stuck inside the handle. The thread is going to be a tight fit, which is intentional as the adjustment of the thread controls how much play the button has. Tighten it until it's snug, then back it out until the button turns freely. If you'd like a little more drag, a dab of thicker grease on the mating faces would provide a little drag.

Reuses the O-ring that comes with the stock cap, but if you don't have that, the stock O ring is a 13x2mm (OD by ring diameter) I had lost one so printed a replacement from TPU that works just fine. Use a pick to remove the O ring from the original cap, just don't freaking stab yourself in the hand. (I didn't, but I know to be careful)

Note: Yes - I realize the “thumb button” has my pointer finger on it, and it's probably a crap name, but I wasn't sure what else to call it. If you know the proper name, lemme know and I'll update.

Print instructions

Pretty much however you want. Should require no supports. I printed at 0.2mm with a 0.4mm nozzle in PETG (Printed Solid for the green and blue and Atomic for the purple and pink) without any tweaks.