"Mass producing" falcate braces

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edvinguitars.fi
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"Mass producing" falcate braces

Post by edvinguitars.fi » Fri Jul 19, 2024 5:17 am

I had some difficulties to persuade my tight grain Carpathian (=European) spruce to bend with traditional bending iron. After few trials, I decided to use the CNC to make bending form a bit wider to be used in my bending machine. The form is ~80mm wide so it accepts 2 pcs of braces 35mm wide in parallel.

I bend the spruce with following setup: 0.3mm steel, 1.7mm spruce, silicone heat blanket, 0.,3mm steel. So far have got 0 failed bendings.
After being encouraged more, I will try to stack the wood to test if I can make the bend at once meaning I would make only one bend to get braces for 3 guitars.

Following the bend, I use the same forms to laminate the 3 spruces together. 2 x 35mm in parallel. This way I can minimize the waiting time and glue curing time and produce enough braces for one year build cycle (at my pace) .
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johnparchem
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Re: "Mass producing" falcate braces

Post by johnparchem » Fri Jul 19, 2024 7:33 am

Timely for me as I was within a day of drawing out a caul for my falcate forms allowing me to clamp them like you do. Luckily I have had no issues bending the laminates.

GregHolmberg
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Re: "Mass producing" falcate braces

Post by GregHolmberg » Tue Jul 23, 2024 7:27 am

Jani, what temperature did you use to bend the spruce?

edvinguitars.fi
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Re: "Mass producing" falcate braces

Post by edvinguitars.fi » Mon Jul 29, 2024 4:22 am

GregHolmberg wrote:
Tue Jul 23, 2024 7:27 am
Jani, what temperature did you use to bend the spruce?
Greg, I bent first pair topping to 150C. That was obviously too much, I have now a brace set with thermo treated spruce to experiment with :-)

Next batches were bent 130C and turned out perfect.

I did find out that Trevor's lamination method with band clamp may be better than the mold I tested: I found some braces having slight gap between laminates (gap filled with epoxy so it should not matter stiffness point of view. )

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kiwigeo
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Re: "Mass producing" falcate braces

Post by kiwigeo » Mon Jul 29, 2024 11:02 am

I also tried molds but found the band clamp method worked better.
Martin

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