Chucking Burl Cap

[CA Savoy]

Need suggestion for chucking burl caps for turning 3 bowls in top. Will need to use 3 different centers. How do I mount to compensate for unbalance ??

Thanks CA

 

[Mark Wollschlager]

CA, try this link, it is a slide show of making something like that.
It was a piece posted on WOW. It might be a bit much.
http://www.wildwoodgallery.co.nz/dream.catcher.slideshow.html

mark.

 

[dkulze]

How big is the cap?

My suggestion would be to take a nice piece of 3/4 inch or thicker plywood or chipboard, mount it up on a faceplate, and turn it to a clean circle (we're talking big here, as big as you can for your lathe). Draw a number of increasingly smaller circles with it on at a low speed. Take the whole thing off, mark the circles and drill holes for set screws. Once you have this backing plate, just sand/saw the back of the burl cap flat and mount it to the plywood. This gives you your basic mounting, which allows for remounting in any position needed to turn your three bowls with different center points.

Now, as to balance. Once you have the cap mounted and the whole setup on the lathe, let it turn free till the heaviest point is downward. Now screw another piece of wood onto the mount on the back side and opposite the low/heavy point. Use different size pieces till the whole rig spins freely and doesn't settle to a specific point. You are now balanced and can turn at a relatively high speed with the balance wood out of your way on the back side.

Finally, just make sure that you don't use drywall or sheetmetal screws to mount your pieces. These will shear off under sudden shock, leaving you with a very mobile piece of wood. Nice, solid machine screws with a broad body, and nicely drilled pilot holes will work quite well.

Dietrich

 

[JimQ]

I don't recommend using the chipboard. It has been known to disintegrate under load. Go with the plywood.

JimQ

 

[CA Savoy]

How big is the cap?

My suggestion would be to take a nice piece of 3/4 inch or thicker plywood or chipboard, mount it up on a faceplate, and turn it to a clean circle (we're talking big here, as big as you can for your lathe). Draw a number of increasingly smaller circles with it on at a low speed. Take the whole thing off, mark the circles and drill holes for set screws. Once you have this backing plate, just sand/saw the back of the burl cap flat and mount it to the plywood. This gives you your basic mounting, which allows for remounting in any position needed to turn your three bowls with different center points.

Now, as to balance. Once you have the cap mounted and the whole setup on the lathe, let it turn free till the heaviest point is downward. Now screw another piece of wood onto the mount on the back side and opposite the low/heavy point. Use different size pieces till the whole rig spins freely and doesn't settle to a specific point. You are now balanced and can turn at a relatively high speed with the balance wood out of your way on the back side.

Finally, just make sure that you don't use drywall or sheetmetal screws to mount your pieces. These will shear off under sudden shock, leaving you with a very mobile piece of wood. Nice, solid machine screws with a broad body, and nicely drilled pilot holes will work quite well.

Dietrich

Thanks Dietrich

CA

 

[CA Savoy]

How big is the cap?

My suggestion would be to take a nice piece of 3/4 inch or thicker plywood or chipboard, mount it up on a faceplate, and turn it to a clean circle (we're talking big here, as big as you can for your lathe). Draw a number of increasingly smaller circles with it on at a low speed. Take the whole thing off, mark the circles and drill holes for set screws. Once you have this backing plate, just sand/saw the back of the burl cap flat and mount it to the plywood. This gives you your basic mounting, which allows for remounting in any position needed to turn your three bowls with different center points.

Now, as to balance. Once you have the cap mounted and the whole setup on the lathe, let it turn free till the heaviest point is downward. Now screw another piece of wood onto the mount on the back side and opposite the low/heavy point. Use different size pieces till the whole rig spins freely and doesn't settle to a specific point. You are now balanced and can turn at a relatively high speed with the balance wood out of your way on the back side.

Finally, just make sure that you don't use drywall or sheetmetal screws to mount your pieces. These will shear off under sudden shock, leaving you with a very mobile piece of wood. Nice, solid machine screws with a broad body, and nicely drilled pilot holes will work quite well.

Dietrich

The burl caps range from 12" to 20" diam.

CA