These are the kits bash ones I made today.
I used parts from the Woodcraft mini stylus.
On this one I used a kit tube at either end, and the middle is tubeless. Later, when I realized they need to be conductive I stuffed the center with tin foil.
On this one I used a 9/32th tube from home depot. It is .14mm bigger then a true 7mm tube. There was not enough friction to hold the fittings in, so I used a drop of CA.
The both work, but just not as well as I would like on either my iPhone or Android tablet.
Now that I have made them, I would not make any more of the woodcraft ones. Penn State Ind has a better system with the replaceable nibs. the nibs on the woodcraft kits are NOT durable. I would not consider either of these to be salable due to the non-replacable nibs.
Zach