WOF 3.5cc Outboard Tunnel

[greenman407]

WOF stands for wood over foam. This is truly a scratch build as you purchase a set of plans designed by Jerry Dunlap. You then purchase the hobby grade 1/32", 1/16" plywood and pink or blue foam. You then cut out the pattern shapes and trace around them on the wood and cut them out. Then you epoxy it to a piece of foam and trim to fit and then on goes another piece. That is an over-simplifacation but you get the idea. I am a K&B fan from way back but for varietys sake I decided to try the new(back then) OS 3.5 outboard. The advantage to an 3924WOF is its light weight compared to epoxy hulls or GRP. If you build it right it will stand up to the vibration as well.3921 3923This is the Hot Shot Sprint ABS cover that you buy from Dumas to cover everything and to give it a racey aerodynamic look.3922

[greenman407]

39263925In these pictures you can see how the upper body is offset to the right. Just an attempt to counter inertia forces and keep more weight on the inside of the right hand turn.

[greenman407]

39283927The shape of the bottom of the sponsons is designed to shed water and reduce drag. All corners and ends of sponsons should be sharp and square to promote a clean exit of the water.

[greenman407]

The height of the bottom of the tunnel is also critical to get the lift you need to get the boat to plane in a controlable manner, not too much and not too little. Then its up to you just like in a submarine to get you CGs right and adjust everything so that repeatable results can be acheived. Problem is that when you have accumulated so many boats and submarine and HO scale trains projects there just isnt enough time to spend with them in a one year period, so they end up sitting on the shelf way too much, then you start to feel sorry for them.