Hi Rob,

In those pictures, the aluminum is bolted to the maple. The holes through the aluminum are tapped, there's a short piece of carbon fiber inserted through the maple and a blind nut on to secure. It's a bit of a trick to get the threads from the aluminum and the blind nuts lined up, but just takes some patience. The aluminum will be drilled and tapped for the engine when the time comes. I've done a bunch this way and so far it works quite well. One of the big, positive aspects is, it makes it pretty easy to change engines. Just cut another set of aluminum mounts and bolt them in.