Please keep us posted. Sounds like you're unlocking one of the mysteries of the Predator if you can devise a working telescoping spear that extends and retracts. If it works as cool as the movie made it look you'll definitely be popular and busy.
Indeed, I thought about doing much the same a while ago, but had so much on I nver got around to it. I did think of using a large flange on the cenral core piece that when pushed up would catch the other segments as it went until it reached full extension
Anyway Love the detail on the piece you've done very accurate by far the most accurate I've seen anyway with the bonus of it extended all the way too. Now just dirty that bad bot up
Boy, there's some real talent signing on the board lately. If and when it does become spring loaded, your spear will be more functional than the original. The AVP spear's opening and closing was done via CG.