Hey Tonyz,
I made the cyclone and blower based on Bill Pentz specs, with a 16" impellor purchased from clearvue oz just before they ceased. Also got a 4hp 3phase motor, and VFD through them.
I hope to detail the build in a thread here once closer to running. But it's basically made from 2mm PETG plastic, with some cold bending and countersunk screws into ply templates/bracing, and some hot forming with heat gun, some glueing with a fancy german superglue that is partly elastic, and some silicone and doublesided super sticky foam in places.