Intro: Making a Simple Form for 3-D Wood Bending
We are going to make a 3-D bent wood form for making a sculpture. See the part 2 to see how this form is used.
Before beginning, please don all your woodworking gear (safety glasses and respirator). A splinter in the eye ball is not fun for anyone.
Materials: Scrap wood that is large enough to make nine circles to the size of your choosing. I am using a piece of wood that is approximately 16" x 14". Hardware- (4) 3" size 6 screws, (20) 3/4" screws (size can be 6 or 8), (1) 2" screw, (10) 1" long brackets with two holes drilled in, it can metal or wood (can be slightly longer, don't go above 1 1/2"). Match the width of your wood to the thickness of your scrap wood. For instance, my scrap wood will be ripped to 7/8" in width so my bending wood is slightly under 1/2" to fit into the form. The length of the wood I am using is 48" in length.
I would recommend oak or ash, they are both great bending woods. I'm using white oak for this demo.
Once you have the bending wood strip cut to size, just throw it in a tube of water or a bathtub to soak and let us get to work on the form.
Step 1: Cutting Holes in the Circles
In order to achieve a 3-D form, you need to add an extra dimension. We are doing that by cutting a hole into five of the nine circles.
We cut the holes by using a 2 1/8" hole saw (smaller is fine) on my drill press. I find it easier to cut the holes before cutting the actual circle templates.
Step 2: Designing a Simple Form
Take the piece of flat board, I'm using some scrap 1/2 inch plywood. Draw four large circles all the same size (demo circles are 5"), draw another four smaller circles (demo circles are 3 1/2"), draw one smaller circle (this is optional).
The larger circles will be sandwiched between the smaller ones to house the wood strip. Think of an Oreo cookie.
Step 3: Cutting Your Circles on the Bandsaw
Once the holes are cut I. The five circles, we will cut the actual circles using a bandsaw. Cut each surrounding circle into manageable blocks then take larger slices of the corners off. When you are ready to make the radius cuts (cuts around the circle) be sure to add relief cuts to the outer lines of the circle in order to get cleaner cuts and to not stress the blade.
Then do your best to cut the circle after your relief cuts are added.
Do not freak out if your circles are not perfectly circular. after sanding, you can also add some cork to smooth out the rough edges as a last step.
Step 4: Cut the Hole Sawed Circles in Half
You will need to cut the donut circles in half. The reason for this is that you will need to unravel the form to take out the final sculpture.
They will be assembled again with the brackets to hold them together again.
Make sure to label the pieces so you can join it back together.
Step 5: Cut a Path for the Bending Strip
Cut paths for your wood strip to bend and weave through the form. The cuts should be in the larger circles. You can use the bandsaw, hacksaw or chisel. The cuts do not have to be perfect. The cuts are approximately 1/2"-5/8" in width. The cut in 5/8"- 3/4" from the outside of the circle going in.
Step 6: Sand Lightly to Smooth Out Major Flaws
Remember that the form is a means to the end so it doesn't have to be pretty or perfect. However, you want the form to be relatively smooth so your oak strip doesn't crack on a jagged part while bending.
I am using a belt sander but you can also do this by hand sanding.
Step 7: Assembly
Now we put back all the parts into an actual form. It may seem more complicated when reading but just keep in mind that your goal is to align and adhere all the pieces into a tower.
1. Use the brackets and 3/4" screws to piece the cut halves of the donuts back together. Use a bracket for each cut. Two brackets per donut.
2. Stack the five donuts with brackets into a tower with the flat side alternating with the bumpy bracket side. Alternate between small and large donuts. See accompanying picture. The cut paths can be arranged according to your preference. Make sure that the aligning and stacking will allow two 3" screws to drill into the entire top stack.
There is room for error since it is a free form sculpture. See picture for reference.
3. When the top stack is assembled move to the bottom stack. Drill a middle hole on the remainder four circles and adhere with a 2" screw. This will hold the bottom stack together prior to adding it to the donut stack.
4. Align the bottom piece to the top donut piece and use the remainder of the two 3" screws to put the whole form together. See picture above.
That's it! You have a simple but effective 3-D form for wood bending.
If you still have large jagged pieces, you can glue cork or fabrics into the smaller circles.
Check out how to use the form to wood bend. "Bending wood using a 3-D form" on Instructables.