Vacuum Pump

Messages
42
Location
Frisco TX
For those that read my long diatribe about making collection plates, there was a sidebar comment about my making a vacuum pump. Here it is. It is about 98% complete. I'm missing a cable protector for the power cord that is rubbing against the knock out hole on the switch box. I also have a leak most likely in the headstock vacuum adapter. I applied several coats of sanding sealer to the outside but probably should have done the inside, too. Not a big problem. I still get 20-21in/hg through the entire system which is enough to collapse a thin bowl. The pump draws 25-26in/hg until it hits the headstock vacuum adapter.

At last month's woodturning club meeting, some guys did a demonstration on vacuum pumps. They bought several kits comprised of the pump, inline filter, muffler, some pipe fittings, gauge and double-sealed bearings. For a $100 I bought a kit and with another $37 you see the end result. My $37 included the valves, some additional pipe fittings, tubing, power cord and threaded brass lamp rod.

Here is the recylced piston pump setup mounted to a board and wired to a simple switchbox with a 9' extension cord. Wish I had gotten a longer one. The muffler is the small brass piece protruding from the back top left corner of the pump. Much needed.
IMG_0034.jpg

Here is the inline filter and large gauge. From a distance, my 50 yr old eyes can see the pressure just fine. The valve at the junction allows me to vary the pressure going into the headstock by diverting air down. I am missing another muffler on the downspout but the noise isn't that bad when being used.
IMG_0035.jpg

This pic is showing the headstock vacuum adapter I turned for my Powermatic 3520B. This adapter mounts in the hole on the handwheel with a friction fit. The core of the adapter is 2 double-sealed bearings (epoxied) and a pipe-fitting also epoxied. The brass lamp rod which runs through the headstock and out the spindle is also epoxied into the adapter. The bearings allow the headstock to spin freely. The valve at this end allows me to turn the pressure off and remove or re-situate a piece...without having to walk over to turn the vacuum pump off/on.
IMG_0036.jpg

This pic shows the spindle-side adapter. Instead of turning one to fit the #2 morse taper, I re-used the one from my Holdfast setup; however, I did add the nut on the end to securely clamp the setup to the headstock spindle.
IMG_0038.jpg

This pic shows the 3 different sizes of vacuum chuck I made. I used PVC couplings not pipe. Couplings are thicker. Each chuck is mounted onto the spindle with a tapped & threaded block of maple (and walnut). I had a supply of maple that I had threaded a year or so ago. I used them for jam chucks for various pieces. Two of them weren't really long enough and hit the brass rod/nut. So I laminated some walnut to the maple chuck and cut out the recess. I still get maximum holding on the threads. Then it was simple to size the chuck to fit the inside diameter of the couplings. Generous epoxy and clamping, profiled the PVC edge then I CA glued some orange Funky Foam to the rim. Funky Foam will hold a vacuum and still protect the piece.
IMG_0037.jpg

I'm hoping you can see the threads in this pic.
IMG_0039.jpg

There are tons of folks who have posted how-to's online. I have zero electrical/mechanical background.
 
Nice work Chip!! I have a Vac pump for stabilizing and will be doing the chuck thing very soon. Thanks for the ideas!!
 
Jim....I would like to see/know how you setup your pump for stabilizing. I've looked at buying a vacuum pot from Harbor Freight like I see lots of folks using for both vacuum and pressure. My interest is in using it with resins. I have some pine cones my wife brought back from Czech that I would love to embed/impale/impregnate (verb escapes me) then turn them. Same with some magnolia seed pods. I seriously have no mechanical skill.
 
Chip,
That's a nice looking system.. would love to have a dedicated vacuum system, but the pump and components are a little beyond my budget for a while yet.... I do have a couple of homemade chucks... one a sheet of MDF covered with closed cell foam and another that's a PVC fitting recessed into a double thickness of MDF with bearins and a lamp rod through the headstock, I can attach my shop vacuum to the chucks and pull enough vacuum to hold most bowls to clean the bottom off.... I don't have a gauge on the line so I don't know what the vacuum is, probably nor more than two or three atmospheres.... if I try real hard I can pull the bowl off, but not easily.... as a safety measure I keep the tail stock up until the last minute.... I had a bowl come out of a Longworth chuck with disastrous results, so not sure what would happen if it came off the vacuum... just not taking chances.
 
Top