Catenary cuts made easy

[simonm]

Hi all,

I am sewing up a hammock tarp using Xenon Sil for a mate and will do up some instructions for making it but thought I would post how I did the catenary cuts.

Measure and mark the mid-point between your two points.

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From the mid-point measure and mark the maximum deflection that you wish to achieve. In this case I am using a 100mm deflection over approximately a 1700mm distance.

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I then use some 6mm dowell and some heavy weights to create the curve, which I mark and then cut. It would not be a technically accurate catenary curve but given the variances in cutting, and forming and sewing the hems it provides a very functional and aesthetically pleasing catenary curve.

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Lightweight tarp 056_640x427.JPG (74.81 KiB) Viewed 7053 times

[perfectlydark]

Neat cuts man! I used the hanging string method first time but had trouble marking the line accurately. 2nd time i just cut off the cuff and it turned out pretty good. I just folded the edge in half (to get a centre point), went down to my desired depth and cut in a.curve towards the joined edges (doing this keeps the symetry pretty well)

[simonm]

@perfectlydark - there is definitely a number of ways to do it.

Here is the finished product.

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[undercling-mike]

By heavy weights do you mean rolls of webbing?

Nice work! I've also done the string method to make cardboard templates but this looks like an easier method and as you say the deviation from a true catenary is probably within the margin of sewing/cutting accuracy for the shallow cuts we use.

[simonm]

By heavy weights do you mean rolls of webbing?

Yep - I didn't think too many people would have rolls of webbing just laying around .