Hi Jimbo

The venturi vacuum system work very well, drawback to the ones I'm
familiar with is they are very noisy, and use an very large amount of
air, they are very good for use with high flammable material, in our
case emptying gas fuel tanks that had a leak or where there was a
problem with the fuel pumps and tanks had to be taken down.
The vacuum systems used on the wood lathe have always some leakage,
through the wood and or bearings, so in order to have a high vacuum for
small turnings you would have to run an let say 10 hp compressor to
keep up with the venturi, not a problem if you have lots of compressed
air, but not very economical for a home workshop IMO.
I happen to have a venturi from an evacuation setup that was scrapped
and I rescued the venturi, gauges and valves, I even gave it a try on
my lathe, but thought better of it and use a small compressor instead.

Have fun and take care
Leo Van Der Loo