I have pretty much tried em all...wood, ramp, rail ground drag, dolly...so far the Dolly Bungee Launcher is the best.

Here are some pics on building a wood launcher:

http://www.rocketryforum.com/ctulank...=bungee%2Fwood


A few more on building a pvc launcher from the your zagi plans:

http://www.rocketryforum.com/ctulank...r=bungee%2Fpvc


Some of the PVC assembly with the option of using padded rails or a ramp, depending on the model:

http://www.rocketryforum.com/ctulank...php?dir=bungee


A few of a better rail system with low drag (the last two pics):

http://www.rocketryforum.com/ctulank...f4dfirstlaunch


How to build a Dolly:

http://www.rocketryforum.com/ctulank...bungee%2Fdolly


The Dolly Assembly and how it works:

http://www.rocketryforum.com/ctulank...gee%2Fassembly


Note that I do not have any pics of building the pedal release, but it was easy with a cost of about $7 in parts. I used a 2' piece of 1 x 4 oak cut to 11" and 13", then bolted one of those door hinges that are sprung (2 in a pack for $4) with 6-32 nuts and bolts in the center of the top piece. I then drilled a 1/4" hole in the front bottom and cut the head off a bolt and installed it as a pin, then drilled a 1/2" holt in the top oak pedal. The rear was drilled and a piece of 1/8" nylon string and steel loop is added and a 12" nail with a fender washer anchors the pedal rear to the ground...real easy.

The reasons I like the Dolly bungee best are portability as I can keep everything in a small case, ease to set up, no large ramps or rails to haul, no wood setups to get wet (the bottom of the pedal was glazed with epoxy to seal it), and smooth ride the wheels give, buffering it from a ground ride. I have them all, used them all and they all got old, hauling them around all the time...now I only keep the dolly in the car. Let me know if you have any questions.

Carl