A scroll saw would make this kind of bowl a whole lot simpler. Cut rings instead of half rings. The cut on a scroll saw is a LOT smoother than a band saw makes.
Cutting half-rings on a bandsaw (for a ring-laminated bowl)
I am trying to make a "bowl from a board", where concentric rings are cut from a board with an angled blade, then "reverse-stacked" to make the rough shape of a bowl, then finally turned on a lathe. One technique involves cutting the board in half, cutting out "half-rings", gluing back the cut half-rings back into full rings, then stacking the rings into the bowl blank by gluing up the stacked rings.
Here are some pre-pictures of this half ring setup:
![Pneumatic tool Handheld power drill Wood Drill Flooring]()
![Automotive tire Wood Flooring Floor Composite material]()
I have seen (and built) a band saw circle cutting jig that require the workpiece to have a dowel/pin of some sort attached to/inserted in the center so that the workpiece can pivot around its center while the blade automatically makes a nice circular cut. However, in the case of half-rings, half of the "center" of the workpiece seems to be missing, so there is no way to insert/attach a pin. I saw one method that glued an auxillary piece (the pine in the pictures) of the same thickness onto the edge of the workpiece so that the center "reappeared". Then the circle cutting operation is performed, and the auxillary piece removed (how? as now since you have a semicircle you will not have a parallel edge to run against a table saw fence, or a perpendular edge to hold against a miter gauge to sand off the piece, etc.)
Postponing that problem until later, I went ahead and epoxied a 1/2" dowel onto the "center" of my workpiece+glued auxillary piece. I cut a ring, and it worked perfectly! Then I cut a second ring, and the dowel broke off (and since I was holding it against the table, I didn't realize what had happened until I ruined the workpiece, grrr).
Finally, to my question
.... is there a trick that I am missing to this method? To anyone who uses it - how do you attach the dowel/pin to the half-workpieces? I had not recessed the dowel, as I didn't want to damage the workpiece by drilling holes in it, but maybe this is required and then you have to remove enough material to remove the hole later in the process?
Thanks for any tips!
David
Here are some pre-pictures of this half ring setup:
I have seen (and built) a band saw circle cutting jig that require the workpiece to have a dowel/pin of some sort attached to/inserted in the center so that the workpiece can pivot around its center while the blade automatically makes a nice circular cut. However, in the case of half-rings, half of the "center" of the workpiece seems to be missing, so there is no way to insert/attach a pin. I saw one method that glued an auxillary piece (the pine in the pictures) of the same thickness onto the edge of the workpiece so that the center "reappeared". Then the circle cutting operation is performed, and the auxillary piece removed (how? as now since you have a semicircle you will not have a parallel edge to run against a table saw fence, or a perpendular edge to hold against a miter gauge to sand off the piece, etc.)
Postponing that problem until later, I went ahead and epoxied a 1/2" dowel onto the "center" of my workpiece+glued auxillary piece. I cut a ring, and it worked perfectly! Then I cut a second ring, and the dowel broke off (and since I was holding it against the table, I didn't realize what had happened until I ruined the workpiece, grrr).
Finally, to my question
.... is there a trick that I am missing to this method? To anyone who uses it - how do you attach the dowel/pin to the half-workpieces? I had not recessed the dowel, as I didn't want to damage the workpiece by drilling holes in it, but maybe this is required and then you have to remove enough material to remove the hole later in the process?Thanks for any tips!
David
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Hi Jim,
It's funny you say that - I tried this first on a scroll saw, but found it to be EXTREMEMLY hard to (freehand) keep the cut even within a 1/4" of the line, while the bandsaw (with the circle cutting jig) cuts a perfect half ring. There was also the problem of getting the scroll blade through the workpiece, which required drilling a hole that requires a reducion in the final thickness of the turned rings. Were you suggesting cutting freehand on a scroll saw? Or using the same type of pivot jig? If the later, my question about how to mount the pin stands
It's funny you say that - I tried this first on a scroll saw, but found it to be EXTREMEMLY hard to (freehand) keep the cut even within a 1/4" of the line, while the bandsaw (with the circle cutting jig) cuts a perfect half ring. There was also the problem of getting the scroll blade through the workpiece, which required drilling a hole that requires a reducion in the final thickness of the turned rings. Were you suggesting cutting freehand on a scroll saw? Or using the same type of pivot jig? If the later, my question about how to mount the pin stands
Perfect - I am excited to try it this weekend! (I've screwed this up enough times that this is my time to get it right ).
What is the diameter of the dowel that you used? I had been using 1/2".
Also, just to make sure I understand the geometry correctly, when you rip the board+dowel in half, it will still be attached by a partial circlular cross-section piece of the dowel, right? That is, you'd have to move the fence and cut again, a few times, until you've removed all of the material of the half-dowel before the off-cut will actually separate and leave you with the finished jig, right? And you also have to make sure the height of the blade is set to pretty much exactly the height of the board or you'll end up with less than the full thickness attached with the tape? (If these questions are not clear as just text, I'll take some pictures as I'm doing this to illustrate what I mean. I think pictures are a good idea anyway because I looked for quite a long time and was unable to find exactly how to do this. Whenever you find a hole in the knowledge of the internet, you must fill it! ).
David
).What is the diameter of the dowel that you used? I had been using 1/2".
Also, just to make sure I understand the geometry correctly, when you rip the board+dowel in half, it will still be attached by a partial circlular cross-section piece of the dowel, right? That is, you'd have to move the fence and cut again, a few times, until you've removed all of the material of the half-dowel before the off-cut will actually separate and leave you with the finished jig, right? And you also have to make sure the height of the blade is set to pretty much exactly the height of the board or you'll end up with less than the full thickness attached with the tape? (If these questions are not clear as just text, I'll take some pictures as I'm doing this to illustrate what I mean. I think pictures are a good idea anyway because I looked for quite a long time and was unable to find exactly how to do this. Whenever you find a hole in the knowledge of the internet, you must fill it!
).David
David
You're right and my explanation left a lot t be desired. Let me try this again.
You glue a dowel into a board, through a hole that is centered on the line you draw along the length of the board. You set the height of your table saw blade to cut just through the board. it can be a bit higher, but you want to leave a good length of dowel in tact. Then, you need to cut through the part of the dowel that is holding the two pieces of the board together. You can do that by nibbling away the board, use a flush cut hand saw, or flip the piece onto the side perpendicular to the cut you just made and cut the board and the dowel.
As to dowel size, I don't believe there is any magic. I used 11/16 because that's what I had.
I think that I'm attaching a couple of pics of the final carrier. The face that you see is the one that the double sided tape sticks to.
![Wood Rectangle Flooring Hardwood Tints and shades]()
![Wood Rectangle Flooring Hardwood Tints and shades]()
You're right and my explanation left a lot t be desired. Let me try this again.
You glue a dowel into a board, through a hole that is centered on the line you draw along the length of the board. You set the height of your table saw blade to cut just through the board. it can be a bit higher, but you want to leave a good length of dowel in tact. Then, you need to cut through the part of the dowel that is holding the two pieces of the board together. You can do that by nibbling away the board, use a flush cut hand saw, or flip the piece onto the side perpendicular to the cut you just made and cut the board and the dowel.
As to dowel size, I don't believe there is any magic. I used 11/16 because that's what I had.
I think that I'm attaching a couple of pics of the final carrier. The face that you see is the one that the double sided tape sticks to.
Attachments
3
I've never made a bowl like you're describing but I have made another kind of bowl on the bandsaw but it required either a glued up block made from boards glued together or a from a tree log or limbs.
This one was made from a log, Texas Cedar Elm.
This Nesting bowl set, I made from Live Oak and that was my last time working with Live Oak, hard as rock.
Then I've made some odd shaped bowels, these were made from Mesquite Limbs.
This one was made from a log, Texas Cedar Elm.
This Nesting bowl set, I made from Live Oak and that was my last time working with Live Oak, hard as rock.
Then I've made some odd shaped bowels, these were made from Mesquite Limbs.
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