Re: string jumping off the sled
Sorry I missed this thread back in December.
I am in agreement with the guys that the "jump" is due to not having the cocking rope start spooling to the left, in which case you should pull it all the way out and start cocking while pulling the cocking block and rope way over to the left. Then when you pull the cocking block down to hook it to your string in the future, you want to be sure you don't pull it out any farther than needed to hook it up. If you pull it too far, it will unspool all the way and may not start winding to the left as you want.
Sometimes the cocking rope is installed a bit to short so that when you pull it out just far enough to hook it up, it actually is unspooled all the way and you're back to square one. If this is the case, the cocking rope should be replaced and installed slightly longer so that when you pull the cocking block out just far enough to hook it up, there is a wrap remaining on the spool. This will ensure that it always starts spooling to the left.
With all that said, when the cocking block jumps because it's spooled the wrong way, the firing mechanism should NOT fire. Obviously that is dangerous. I would strongly suggest that you have the cocking block serviced or replaced by a dealer or PSE. The only way it should fire is when the firing mechanism on the underside of the cocking block is struck by the hammer.
If you need more info feel free to give me a call.