Large Birch Burl on Stubby Lathe
I turned a large birch burl on the new Stuby S1000 lathe. This is the second large burl turned on this lathe, so I am giving the lathe a real work out and learning how to best use all the special features. This burl was heavy and very unsymmetrical requiring the use of my shop crane to lift it onto the lathe. Images in the gallery below show the details of turning this burl. I used both tool rests and repositioned the movable bed several times to be able to easily reach all parts of the burl with the tool rests. This burl is full of chatoyance (flaming curl figuring) and although the wood was green, it was very difficult to carve. I actually used my smallest 1/4" gouges for most of the turning so this one took two days to complete. The images below show the story. What you don't see is the difficult carving and the need to add 120 lbs of weight to the Stubby lathe. I used sand bags in the center section of the lathe on the flat steel bottom plate which sits on the floor. This is not shown in the images. The burl's uneven weight distribution caused the lathe to start "rocking" at speeds over about 280 RPM. I could achieve 350 RPM with the added weight and a bit faster near the end of turning. The lathe weighs close to 1000 lbs so I was surprised to need the extra weight. I also plan to screw the lathe to the concrete floor. This was the most difficult bowl I have turned, mainly due to the unusual hardness of the wood. I have no idea why this burl was so hard. Birch is usually easy to turn. The bowl measures 24" x 18" at its top, 5" deep, and average wall thickness of 3/8 to 7/16". The wood has amazing chatoyance and some interesting colors and inclusions. Its unsymmetrical nature is interesting with a large wing on one side. The dark bark edge nicely frames the lighter glowing wood of the bowl. This one will take at least 3 months to dry for finishing. A note about the Stubby lathe. I got this lathe to turn large unsymmetrical pieces like this one. The lathe performed exceptionally well. The flexibility of positioning the tool rests and the ability of the lathe to hold large (up to 44" diameter) pieces by sliding the bed was important and these features worked well. The 3 HP motor also was important and it never stalled or slowed with this burl. I am extremely happy with the lathe. I could not have turned this burl with any of my other lathes (Powermatic 3520 and Vega 2600).
