Inspired by a coment by Fester. I had a go at making one using a fermentation bin, I had lying around. It worked brilliantly until the hose blocked, the bin collapsed spliting down one side. I sealed the split, inside and out with gaffer tape and pushed on old builders bucket into the bin to reinforce it. I cut a 30mm hole in the lid for a pressure release valve which I knocked up from ply with a scrap spring, using a bit of foam wallpaper underlay as a seal. It works fine now collecting dust from the lathe but when I want to vacuum shavings I get blockages in the hose, which came from a scrapped Dyson. I used 1 1/4" PVC waste pipe and connectors that I had for the connections. This is really too narrow and shavings can easily build up and block the hose. All this said I'm really pleased with it as its capacity is twice that of the Henry which drives it and much easier to empty. The pressure release doesn't leak but works when the hose is blocked. If I were to make it again, had a different hose and 1 1/2" fittings I think it would be much better.