The vacuum pods on our smaller machine are made from Tufnol / SRBP (Use the stuff from DirectPlastics), i think its absolutely horrible stuff to work with, stinks and iirc some types can be carcinogenic. On the larger machine the vacuum pods are machined from a dense type of Phenolic Plywood, much nicer to work with and doesn't appear to be affected by moisture, the stuff we get is 80mm thick.

On a separate note this machine is epic can't believe i only just found it! That Z Axis is a thing of beauty!

Alex