mechanics wise, I have to say that this is definately a good place for you to store an extendable weapon. it's kind of funny because i implamented the exact same style of transportation into how i carry around my collapseable Tai chi chuan sword. there are, however, some bugs i have noticed in the drawings, one of which is the problem dealing with the scabbard.

logically, I tried the simple wristband idea you have and found out very quickly that it is surprisingly unstable due to it having weight distribution issues. just the wrist band alone would not be enough to keep a weapon of the type secured propperly due to the ammount of stress. what i did was to take the length of the scabbard and incorperate that onto a type of arm rig that went up by the elbow on the forearm behind the wrist. that reduces slipping and shifting, as well as gives your non dominant forearm more protection from attacks like with a buckler or small sheild gauntlet.

secondly, moving components are hassles. that swivvle mechanizem you have is a bad idea. if an enemy really wanted to get at your weapon, they'd be able to snap that pivot point with an attack and disarm you. instead, I recommend a secondary and tirtiary set of tactical mounting that would be better suited for combat situations. the second style is a normal belt loop on the back of the scabbard. when you take the rig off your arm, it would work the same as a K bar combat knife scabbard. the third style is in the lower part of the scabbard that allows you to mount the blade on your belt at an angle for quick and easy drawing styles. if you want, I can send you some images of my rig so that you can see what I'm talking about.

lastly, the actual way the blade rests in the scabbard is an issue. when i was looking at your design, I noticed that it came over the handle in a type of sleeve style scabbard. that gets problematic due to the fact that you can't get the blade out in time if you are attacked. I recommend instead of a sleeve, a pop clasp style that's scimilar to that of how an actual K bar combat knife is secured. that way, not only could you slide the blade into the scabbard in it's retracted form and secure it with ease, but it would allow for a quick unclasping and drawing manuver that no one really suspects. it also leaves room for you to utalize a weapon with a gaurd more effectively so that you don't need to worry about structural integrety on your weapon's end when it retracts into it's stored state.

if you need any more info, just let me know so i can be able to help you out.

o_o wow, you really worked this all out... I'm gunna have to read this several times to get everything. lol To be perfectly honest, I wasn't thinking along the lines of a fully collapsible weapon. The idea was more along the lines of a magic trinket of sorts. In fact, everything is way smaller when it is in bracer form. ^^; However, that's not to say I won't take what you've said into consideration in the future. Everything you said is actually quite fascinating and I would like to see the device you rigged up if you don't mind. ^^ Your comments, as always, are much appreciated and always interesting to read.

no problem. I'll get on working up a diagram for you so that you can see what I'm talking about. worst comes to worst you'll be seeing some cell phone pictures of the scabbard design in my archives.

this might help you out a bit more on what I was talking about.

http://www.furaffinity.net/view/3407664

I threw it together really quick so that you could have a visual reference. if you find this helpful, give a review on it if you want.

very cool ^^ I'll take it under consideration.