How to make a Vacuum Chuck
Copyright Ron Sardo 2008

Here is the way I made my simple vacuum chuck. At the bottom of this page is a material list and suppliers.


Image I start with  furniture grade, lumber core, 3/4" plywood. Since I’m using scrap pieces left over from a different project, I pick out pieces that approximate in size. Also, I have made this chuck using MDF with equal success. The most important thing to consider here is that the base has no voids.


The larger piece is the faceplate and measures about 7". The smaller piece is a support plate for the bolt and is about 4". The size of nut shown here is 1-1/4" x 8tpi, your lathe may be different, so you may need a different sized nut.

As luck would have it, the biggest forstner bit I had was 2-1/8" and the widest part of the nut measured 2-3/8" , so I used a chisel to cut the notches for the bolt to fit. This probably made for a more secure and better fit.

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Image Using epoxy, I glued up the three pieces and let sit over night to cure.
Image The next day I round over the support plate and the face plate.
Image Front View
Image Using a parting tool,  I cut a recess for the plastic coupler about 3/16" to 1/4" deep. Because I want the coupler to spin true (centered), I’m careful to make sure the outer edge of the recess is the same size as the outside of the coupler. On the inside, I remove extra material so there is some room for the epoxy.

Next, I cut the recess for the bearing. I like a tight fit and make the recess as deep as the bearing is thick.

Then I drilled a ½" hole for the lamp rod.
Image Since each lathe’s headstock is different, you’ll have to determine the proper length that you need to cut the lamp rod. I eyeball it by holding the rod next to the lathe, with one end past the plate we just made and the other end past the hand wheel. Remember, it is easier to have it to long and cut a little more off than to try to glue a piece back on.

I chuck up the lamp rod into my pin jaws. With the lathe spinning at a slow speed, I file away a section until the rod not only fits inside the sealed bearing, but is also a little longer then the thickness of the bearing. I want a tight fit, almost a compression fit. So I take my time to make sure it is right. This took me about two full minutes to get the dimension that I need.
Image

Next, I epoxy the bearing in place and let it dry overnight

The following day I insert the lamp rod and flare the end so it stays in place. I don’t use any epoxy here. The last thing I want is for the bearing to be locked in place.

Then I epoxied the PVC coupler in place and again let it sit overnight.
Image Here is the finished vacuum chuck along with the foam sheet cut into a donut.

The last vacuum chuck I made I would glue the foam to the chuck. I decided to try to keep it loose just to see how it works.

I use the foam sheet as a gasket between the stock and the chuck to aid in a good seal.
Image Here I'm rounding over the edge
Image With the lamb rod though the headstock, I connect the tube which supplies the vacuum.
Image Here is the chuck mounted on the lathe.
Image I use the foam sheet as a gasket between the stock and the chuck

Spinning test piece at 897 RPMs.  So far so good!
(Camera stopped motion)
Image For a test bowl, I decided to start off small to work any kinks out that may arrive.  Notice the little hole in the center, this hole was made by the live center when I was first turning a tenon. Now I will use this same hole to help me align the bowl on the vacuum chuck.
Image All lined up, tool rest in place and ready to turn.
Image  In no time at all I cleaned off the tenon, so far everything is running smoothly.
 Image  Here I am decorating the bottom.
Image  
Image Bottom sanded and finished
(Stop motion again.) 


Now for something serious.
Image

Here I have a 18" Natural Edge Bowl all set and ready to turn.

This is a crotch from a black cherry tree.
I can't wait until I apply a oil finish, the figure has allot of promise.
Image I turn off as much as possible with the tailstock in place.
Image
All Done!

The chuck worked great.

(Stop motion image)


Below are the materials I used.
The links provided are just suggestions
 and are used just to show what the product looks like.
Image Nuts

These can be purchased from Enco, MSC or McMaster.
Most lathes are either 1" x 8tpi or 1-1/4" x 8tpi, but this size may vary.
You need to determine the proper size that you need.
Image Bearing

This can be purchased at a local big box store or a automotive store. Remember you need a sealed bearing to hold a vacuum.

The bearing I used has a 0.3120"  inside diameter
Image Lamp Rod
3/8" by 30"  This can be purchased at your local big box store.
Image 4" PVC Coupler

This can be purchased at your local big box store.
Image Foam sheet

This can be purchased at your local craft supply store.