I've tried the shooting machine with a 30# bow from a fixed 27" draw.
I've lightened the back of the stock a bit so it balances better and screwed a chunk of aluminium in front of the trigger mechanism as a fixed stop to hold it at 27" draw.
It shoots nicely, but with a weak bow slightly under drawn, the arrows are a bit stiff and kicking left. The basic design has certainly been proved, but I don't trust the trigger mechanism for anything much heavier.
Over the holiday period I should get some interesting video and work on a more robust version of the trigger and the sliding release.
Lovely tiller on that little 30# Hazel, it's one of my best bows, it was the one that Ruth Goodman shot on the TV program.
Update:- I've tried with the sliding release, cocked and loaded the bow at about 20" and then pulled the trigger mechanism back using a makeshift handle made from a wire coat hanger. As it gets back to 27" the trigger gets lifted by a block that I'd screwed in place.
It was rather awkward to operate but released ok. I was V close to the target and the arrow struck home whilst it was still flexing and flying at an angle, so it embedded 2" into the target and snapped off the shaft. It will be interesting to see it in slo-mo once I have the fancy camera.
I've just shot "twister" from outside the garage, so that's 10 yards. Perfect shot, lined up pretty true and struck the target square, just shows that with the right arrow and bow it shoot correctly :)
Cant wait to get some video but I'm not allowed to open the camera until Christmas!