I just got a hold fast vacuum chuck system and have tried it on a couple pieces; I found that I could even use it for reverse chucking a hollow form, as it held a tight grip. I got both the 3 1/2" and the 6 1/2". It uses what they all a "generator" and your compressor. I know many have made up their own system with a vacuum pump, which I'm sure is much quieter than my rattling compressor (it's a 60 gallon quincy). I'm asking if anyone has any tips for using a vacuum chuck?