I got my Dodo yesterday and my first impressions are on another thread in this forum. It was VERY hard to close the knife because the ball didn't want to move much, but I figured that was normal.
Last night I noticed that light-moderate hand pressure on the spine of the knife is enough to collapse the lock! I did it over and over again, but I had adjusted the pivot earlier, so I thought that maybe the pivot was eccentric.
This morning I adjusted the pivot again and it seemed to fix the problem, but then it came back again. I noticed, too, that the lock would not really engage if I open the blade really slowly. At the same time, the knife started getting very difficult to open and close and it felt it was "gliding" on rocks. I had read the thread about another Dodo having the piston get jammed in the channel it slides in, so I figured that was the problem I was having. The lock was working miserably at this point and I could pinch the blade between my thumb and index finger and pull down and the lock would collapse with that meager pressure.
I opened the knife up and found metal flakes in the piston channel. Also, the little spring that is wrapped around the piston was jammed in the channel the piston slides in. About two turns of the spring were jammed there, and they were biting into the piston, which accounted for the rough action and the repeated lock failure. I pulled the ball and piston out, got them back in properly and everything seems to work a lot better.
I still have one problem, though: if I open the kinfe slowly (like someone would who is unfamiliar with knives), the lock will still collapse under light hand pressure. If I open with my thumb, normally, no problem, but any slow opening, even if the ball and lock "grab" the tang at the end of the motion (open your Dodo slowly and you'll see what I mean) I can get the lock to fail.
Maybe mine is defective and I need to send it back to Spyderco. But, based on this experience and a couple hours of obsessing about this problem, I see a few things worthy of discussion:
1) Is there a way to fix the possibility of the spring jamming in the piston channel? In my case, the first sign of a problem was complete lock failure. I'm lucky that my fingers were to the side of the scales at the time.
2) Why does the ball only engage a tiny portion of the tang? It seems that the problems I'm having now are related to this. A snappier opening seats the ball in the tang a bit tighter and the lock is strong, but with a weak, slow opening the ball still engages the tang, but not as good as it should, and it rolls back and unlocks under pressure to the spine of the blade. Why not have the ball engage more of the tang to prevent this?
Again, maybe my knife just has some serious problems but it seems unlikely in a production knife that one could get through with problems like this when they're being ground on the same machines, fixtures, etc. I'd love to hear a discussion on this lock design. I think it works great when it works, but it worries me a little to think that I have to open it just right to get it to work. With my other Spyderco's, I know when the lock is engaged.
The worst part about this sort of thing for me is the waiting part! Even though I haven't even really used the knife, I was really wishing I had it, too. It is one super knife and it will be in my pocket daily for a long time.