I work in the medical field and really really wanted something with a penclip. And it seems that they don't really exist...at least not in a way that I was happy with. So I decided to make one.
It's made from a disposable penlight (that I hadn't disposed of yet) and uses a 10440. The "actuator" is the clip itself. I suck at soldering so I took a piece of aluminum rod and whittled it down and stabbed it a couple times with some drill bits for the 510 connector and the battery. I did end up having to solder the connector in, but with a gentle use of a pen torch and some solder, it's stuck in the hole for good without leaving any evidence. Here's it disassembled:
It's pretty simple really. The aluminum part is friction fit, but with some careful measuring and a little tweaking of the spring at the base and it's happy. I can shake it roughly and it won't fall out. But with a tug, it comes right out to change the battery easily. I'm a little new here and I'm curious as to what y'all think. If you want more details or pictures, just ask.

It's made from a disposable penlight (that I hadn't disposed of yet) and uses a 10440. The "actuator" is the clip itself. I suck at soldering so I took a piece of aluminum rod and whittled it down and stabbed it a couple times with some drill bits for the 510 connector and the battery. I did end up having to solder the connector in, but with a gentle use of a pen torch and some solder, it's stuck in the hole for good without leaving any evidence. Here's it disassembled:

It's pretty simple really. The aluminum part is friction fit, but with some careful measuring and a little tweaking of the spring at the base and it's happy. I can shake it roughly and it won't fall out. But with a tug, it comes right out to change the battery easily. I'm a little new here and I'm curious as to what y'all think. If you want more details or pictures, just ask.