Kerf Spacing Calculator for bending wood

[Greg Tarrant]

Ive just added a Kerf Spacing Calculator to blocklayer.com, that some of you may find useful.
It works out the geometric spacing of the cuts so when bent, the inside edges of the cuts join to create the curve.
The depth of the cuts (and remaining wood thickness for the bend) can't be calculated (that I can work out anyway). That seems to be the art of it. Depends on the wood and the dimensions. Trial and error?
But this will produce simple geometric diagrams, so you can see the wood and cuts both straight and bent, and drag sliders to animate angle, radius, cut width etc to see what changes.
It also creates a full scale template to mark out the cuts.
'https://www.blocklayer.com/kerf-spacingeng.aspx
It obviously can't be 100% accurate, but should give a pretty close idea of what sort of a bend you'll get for the entered dimensions.
If it needs editing, additions, fixing or you have any other ideas for improvements, please let me know.

[Eduard Nemirovsky]

Thank you for link and info

[Mike Cutler]

Greg

Is that your work?
That's pretty cool if it is. It's definitely a valuable calculator.

Is "arc sweep" the chord length?

I think it would be difficult to add the species variable. I guess there are acceptable modulus values for each species of wood, but then you get into kiln dried, versus air dried, and other, more independent variables.

[Greg Tarrant]

Thanks Mike. All the calculators on the site are my work. The Arc Length is just the length around the curve. Same as the length when flat, before being bent. Geometrically, only the bottom edge of the wood gets shorter when bent, closing up all the cuts. The Chord length is marked at the bottom of the diagram. Maybe I should re-label the Arc Length as Length around curve ?? Its difficult to find the best description for some of these dimensions. All suggestions appreciated.

[Mike Cutler]

Greg

Nice work!

I kind of figured that I was misunderstanding something. I put in the values, radius and chord length, for a bow front vanity I made and watched the kerf cuts images change. It didn't look like enough to me. I'll do it again just for fun.

I have a bow front traveling vanity project in the works. It's actually a portable horse show, tack trunk/ wardrobe/ vanity, and I wasn't looking forward to steam bending a bunch of stretchers, rails, and drawer fronts, even though I bought enough green, now air dried, walnut to do a 1/2 dozen of them easily. Much quicker if I can just bend it around the kerf reliefs.

I like it. :cool: