Hold Down Channels?

[daffelglass]

So I'm trying to build a machine with an extremely minimal amount of tools and money, and I was curious about the purpose of the hold down channels on the cutting board. If those were not necessary, I wouldn't need the awkaward pieces of aluminum or the strange cuts down the center of the MDF. However, I believe that the channels are important for support of the surface, and advice would be appreciated

Many Thanks

[daffelglass]

nevermind, I now see that that was a stupid question. Please ignore it