But I thought you had decided not to go with bamboo but with something more like the first stem you've posted, no?
The shape will be much more like the first stem I posted, but it will still be made from bamboo. The reason I like bamboo over hardwood is that bamboo is more tough, hard, water resistant, easier to drill, and IMO looks nicer.
Here are some photos of the tips getting ready for the testers.
I made a jig to bend each bronze spring, but I'm not showing it
Here is my personal tester that has been doing really well, as you can see there will be some small changes to the tip that aren't exactly obvious at the moment, but it'll make more sense later.
You can see how the heat has changed the colour of the patina on the steel to a more reddish hue nearer to the tip. I like it!
The metal screen does accumulate some ash, but it doesn't seem to go past this first screen into the herb chamber. I haven't cleaned this at all either, you could just brush it off easily.
Here is the small box that inspired my eventual box design. I've been carrying this around for a bit more than a year now. For the time being I have been using it to hold charcoals. I can fit about 50 charcoals into this box, so it could be good for about a month of off-the-grid vaping if you like to vape a couple times a day.
My box design will be about half the height of this box, but a little bit longer in length and width. I'd like it to hold about 25 charcoals and the okin. Or, perhaps more like 12 charcoals, and space for a small glass herb caddy. I feel like I could leave it open enough so you could pack it differently depending on how you want to use the okin. You could load it up with 5 charcoals, an AVB jar, a herb jar, and some matches. And that would be a very portable package!
If you did that, you may choose to glue a match striking strip to the side of the box.
You can also take the rectangular box cover, load your herbs into it, then tip the cover so that the herbs fall into the corner, and tip the corner into the chamber for loading... if that makes sense...