Single setscrew to hold the core in place doesn't cut it.
I received this on/off for free from my local proshop - he got one in for testing and wanted to see how it performed. Packaging was simple and to the point. Everything about the on/off is fairly easy to figure out just by looking at it.
The mounting options with this on/off are interesting. The on/off has a rail clamp for use on normal dovetail mounts, but it also has a small insert block with two screw holes for screw mount, if you so desire. There's a big grub screw on the side that clamps the cradle onto the core and either the screw block or a rail (if you're doing a rail mount). There is also a small grub screw on the bottom that provides holding support for the core.
I tried to attach it to the rail mount on my drop, but I ran into a major problem. The sizes arn't quite right, so the cradle can't clamp down on the core (the part that you screw the bottle into) and the dovetail rail with the same force. On mine, the rail was a bit larger so the core would not have any pressure holding it other than the setscrew. Because of this, the setscrew had to be tightened down until it scratched the coating - and it still didn't really have enough force to hold a tank in place.
So, thanks to the multiple ways of mounting this on/off, I just put in the screw block and screwed the cradle onto my drop - problem solved.
The air line mounts to the front of the on/off, which is a huge plus for me. Side mounted lines just don't work well with my setup. Also, you don't have to redo all the fittings when you want to take the on/off off - unlike the unimount.
The action of the on/off is quite slick. There's a silver knob on one side and a red knob on the other. Press the silver knob in and it presses the tank's pin and turns the air on. Press the red knob in and it shuts off the tank and drains the air line. Turning the air on is fairly easy, you shouldn't be able to bump it on but it doesn't take too much effort. Turning the tank off is another beast entirely - with my PMI high-preset tank you have to use two hands or a hard surface to press in the red knob and shut the air off. I think the resistance would be less on a low pressure tank, but I like having it high - it means I will never be able to accidentally turn off my air.
The on/off comes with two extra o-rings for the slider, and there's a good reason for it. Within two weeks (four solid days of play or about 20-30 on/off cycles) one of the o-rings blew out and had to be replaced. Replacing the o-ring is difficult if you don't know how - the red knob has wrench edges but the opposite silver one doesn't. I used some rubber sheet to get a good grip on the silver end and used a wrench to turn the red end, once it's off the slider assembly comes out easily and the o-rings can be replaced.
Given the problems I've had with this mount, I wouldn't buy it for the price it retails for. The action is nice and the concepts are great, but I'd expect the o-rings to last longer than they did. If it were cheaper or they gave you more than two o-rings with it, then I'd probably recommend it as a nice replacement for a uni-mount. Nothing's perfect, after all.
7 out of 10
Last edited on Tuesday, November 2nd, 2004 at 1:24 pm PST