reminded me, I've been intending to ask on several occasions but get off into other tangents and forget... seems to be a tendency here of late...
I've run into several occasions where a vacuum chuck would be handy, but not sure what size pump to look at and how complicated is the set up... those of you who use a vacuum chuck, do you have any recommendations?
Keep in mind that my knowledge of any kind of air hook ups... either vacuum or pressure is some where near or below the level of zero.
I built a rotary vacuum adaptor for a friend in Texas once ...
Beyond some sort of vacuum adaptor like that one, which supplies vacuum into your vacuum chuck, the setup is pretty simple. You need a pump of some sort to pull the vacuum. You need a hose to get that vacuum to the lathe. You need a rotary adaptor to permit the work to spin while being held by vacuum. You need a vacuum chuck (easily made in your own shop)... and you need some sort of seal against the wood being turned. A large rubber or Buna-N o-ring works well for a seal; it should be made of small-diameter rubber so it doesn't flex much when tool meets wood. The diameter of the o-ring should be as large as you can deal with for the workpiece at hand - too small an o-ring encourages wobble.
Oh, and... someplace inline you'll need a water separator & filter. The water separator helps keep water from the wood out of your pump. A vacuum pump can suck all SORTS of stuff out of things - including all the lubricant out of the bearings in carelessly-made rotary adaptors.
I'll let somebody else speak to pump size - the kind of wood being chucked will make a lot of difference, though, and the grain orientation will, too. Wood is inherently porous, so the pump will need to keep up with the air seeping through the wood into your chuck.
I'll