Safe minimum for hub axle length?

any bike shop that doesnt give you those for free are cunts.

Great drawing tynan, you drew all that with the interlocking threads just for the sake of a post/comment? Well done.

I thought it was easier than doing it in words, only took a couple of minutes. It was all step and repeat in photoshop, I didn't have to draw much beyond a rectangle, one small triangle and a circle.