I have been having okay results with various home made chucks and the vacuum pump I bought from the frugal system guy. I am doing a variety of larger bowls and it seems to me that a flat faced chuck sized to fit all of the larger bowls would be useful. I was also wondering if rubber sheeting like that used as gasket material in some applications or as vibration isolation material would seal well and last longer than craft foam. It seems to be readily available in 1/8" and 1/4" thick sheets. So I am thinking of building a flat faced chuck with a rubber covered face. Is there some reason this is a terrible idea?
Most of the curved faced chucks I have made seem to be inclined to fit one particular bowl size/style really well and pinch/cut the craft foam making the foam a one shot deal. In some cases they have wedged pretty tightly into/onto the bowl. Maybe I didn't design them well, maybe I just need more sizes or styles, but it seems to me as if just using a flat surface might solve all that if it can achieve a decent seal. Granted it wont be self centering, but I can live with that as long as it stays centered once in place and the vacuum is cranked up.
Most of the curved faced chucks I have made seem to be inclined to fit one particular bowl size/style really well and pinch/cut the craft foam making the foam a one shot deal. In some cases they have wedged pretty tightly into/onto the bowl. Maybe I didn't design them well, maybe I just need more sizes or styles, but it seems to me as if just using a flat surface might solve all that if it can achieve a decent seal. Granted it wont be self centering, but I can live with that as long as it stays centered once in place and the vacuum is cranked up.