Aluminium bed for Printrbot Plus (V2)

I made an aluminium bed caddy for the Printrbot Plus (V2) out of 5mm plate due to the wood on my printer being very warped out of the box.

I must give credit to this thing (http://www.thingiverse.com/thing:91504) for inspiration.

It sits over the stock bed to utilise the levelling features. It takes a little longer to heat up completely but once hot, it stays hot.

I'm considering using an adhesive to bond the heating element to the aluminium plate to further reduce the warp in the st