Its screen-used and just a static open head staff weapon cast in a medium weight rubber. I'll look into an open head for a stock replacement to the Legends staff this spring. I have the Legends staff but I can't remember the rod/connection design off-hand.
Brundlefly, I'm not sure what info you have regarding the original 4 working pneumadic powered jaffa staffs from the movie, but last info I had heard on sg-6.net (long gone site) was 2 got into private hands post production... of those 2, 1 was complete (yours I think if you still have it) and the other was actually busted during production. The last 2 were kept in the MGM archive and of those 2, 1 was pulled apart and somewhat reverse engineered to make 6 SG1 working staffs that were lever-switch action to be more reliable... this is also why the SG1 jaffa staff heads opened only about 1/2 as much as the movie staffs... the way the lever was designed in the hand grip, it's short throw didn't allow for full opening of the head leafs as far as they did in the movie. I need to get my CNC 4th axis up and going, I've tinkered with reverse engineering the working staff head mechanism, partially from some of the pictures you've posted and others around the net... but until I get the cnc fully up and going and the interference/missing steps figured out I won't be able actually try and see if my dimensions will work. I can't get Alibre motion to cooperate (I just don't have the time to devote to learning all the little software nuances) to see if there's any problems with my calculated dimensions so it's going to be physical prototyping the hard way and making scrap
My sister (Look for her name in the credits: (Amanda Cerney: Special Effects Office Coordinator) said she was pretty sure it was four. She was there when they Yuma shop got them. She said one never worked, and most of them were broken/repaired/broken during production. In fact, mine has alot of Bondo on it. Most of the shaft section that has Randy's Greeblie details...is Bondo.
I thought once to restore it as I have Randy's casting he used for that section molded...but decided to keep it as is.
If you watch the Palace Scene, Anubis bows with one of the Broken staffs, Its open and missing leaves. (Mandy was there when they filmed it, ) Im pretty sure thats the one that ended up in a NEW JERSEY CLEOPATRA Dispay (screwed to the wall), that eventually went to PROFILES and then PROP Store. It might even be the one that never worked. I dont know.
I had the number 4 confirmed when Jason was over my house recently. His is in the photo with my sister (on the right shown above someplace). He had I orignally met on the set in Yuma. He made the 4 leaves that open for the top of the gun. Randy Cooper made the detailed shaft that connects the opened end to the rest of the weapon. He also did the greeblies on the inside.
The shop that did the Lowes 2 thirds of the gun here is here near where I live. Years ago,, I tried to buy the HORUS bust he still owns, as that shop also made those. He would not sell it, and my last offer reached 15k.
Anyways, Jason said, there were 4 and indeed one never worked.
Im not suprised, MGM would autopsy one for the show. They would have had to destroy it to examine it.
So that means, there is ONE working one, (if it still works) from the Movie,
Somewhere. (And Mine just shot up in VALUE if that is indeed the case, as its the only working one of two that still exist.)
The internal mechanism is pretty simple. If you have my pics, you have everything you need to figure it out. Id provide measures, but honestly, you are better off starting from scratch.
Im sure you can improve upon it.
Im a purist,...and just wanna make repos exactly like the filmed one...except electric.
The pnuematic mechanism takes 80 PSI to operate.