Design #2 - The "Crossbow V.1".
Failure - Well maybe "faliure" is a little extreme but the "crossbow" is definitely not a slam dunk. It seems like it should be prefect, a controlled low friction linear slide, high-tension 145lbs garage door spring and a golf club head. Voilla! Not really. With the spring pulled back as far as I could humanly could (for me) - the golf ball maxed out at 150 feet. And the scientific proof that this desgin just might suck is the fact that pulling back 8" less on the spring only changes the lost distance 10 feet or so. Where are the inefficiencies????

The idea was to use every inch of the 4x4 area - the braces are an even 4' and the center spar is 68". That spring was pulled to is specified limits 110% of its original length. Scary.

A liitle steel welding... a little JB welding...

The slide rail detail.

If you can see whats going on here, just trust me - its dangerous! The winch ratchets back the pivot arm which is tensioned by an 110lbs gargage door spring!

Heres what I finally went with... a crossbow sling shot. Heres the frame.

The latch release mechanism

Ya dont wanna be looking down this thing at this point!
<but I did anyway to get this shot>