Brent Dowell asked about vacuum chucks, and as it just so happened, I was finishing off the bottom of a bowl tonight, so I thought I’d take a few pics of the process. In the true FW spirit, I got carried away on the pics. This is gonna take a few posts.
As Stu mentioned in Brent’s thread, Steve Schlumpf has a great pictorial of his vacuum pump setup. I figured I’d show the rest of the process.
My setup is a little different from Steve’s, but you’ll see some similarities in the rolling pump cart. (I built mine first. Steve improved on the idea and documented it very completely.)
The heart of the system (aside from the vacuum pump) it this little contraption. It’s the vacuum adaptor that allows me to run the vacuum line through the headstock. It’s just a threaded hollow tube, with holes on one end (where the chuck goes) and a swivel connection on the other end where the vacuum hose connects to the lathe. (Otherwise, the hose would be twisted into a knot before you could even start working.) This one is the Holdfast adaptor from Packard’s.
Here’s the end that sticks out of the spindle into the base of the vacuum chuck. You can see the little holes where the air goes.
And here’s the end that goes into the hand wheel side of the spindle. It has a quick-connect hose fitting on the swivel fitting.
The cone-shaped part unscrews from the threaded tube, so you can feed the tube through the spindle from the chuck side of the headstock.
In this shot I’ve pushed the threaded tube through the spindle, but not yet connected the cone to the other end.
This is how much threaded tube sticks out past the end of the spindle. (It comes from the factory longer than needed, with instructions to cut it to size.) It’s the same kind of threaded tube used in lamps, so replacement should be easy if it’s ever necessary.
In this shot I’ve just started screwing the cone/swivel onto the threaded tube.
And here it’s cinched up tight. It only needs to be hand tight.
Here’s the suck-u-tron. It’s the ubiquitous 220v Gast that Surplus Center was selling for a long time. As I said earlier, Steve has a good description of how the plumbing goes together in his thread. We’ll hook it up in a minute.
Here’s the actual vacuum chuck. When I bought the vacuum setup, I decided to start with a factory-made chuck, just so I’d know how a good one is supposed to work. Now when I make others in the future, I’ll have something to compare them to. This one is a 6” Holdfast (again from Packard’s). I have the materials to make a few more, but so far this is the only one I’ve needed.
Continued in the next post...