Cat Cut Layout

**hungh13** · 05-09-2017, 08:29

I have sewed a tarp before but I haven't done one with Cat cut. I am planning to do a hex tarp, and this time I want to do it with cat cut. I was wondering what is the most efficient way to draw a cat cut. I know there is Xtrekker program, but that is connecting the dot and lots of it, and it will take some time. Anyone with a good way to draw cat cut layout? Would appreciate any tips.

**dscotthep** · 05-09-2017, 08:46

Per Wikipedia: "In physics and geometry, a catenary is the curve that an idealized hanging chain or cable assumes under its own weight when supported only at its ends."

Hang your fabric on a wall. Hang a piece of string over it. Trace the curve.

**MattK** · 05-09-2017, 10:19

Hanging on a wall with a string is a very good option. gives you a true catenary curve, and allows lots of adjustment (how tight you pull the string.

I never had that much clear wall space though. So, I approximated. I found the center of the edge that was curving, and marked the depth of the curve I wanted. Then I used a tent pole, anchored it on both ends with books, and pressed the pole in until it came to the mark I wanted for depth. Then you use the pole to trace along. Not a true catenary curve, but once you factor in the imprecision of cutting, rolling a hem, and sewing, it is close enough to function well. I have done this on three tarps so far with good success.

**hungh13** · 05-09-2017, 10:33

cool, I'll try hanging on the wall idea.

**bikerbobber** · 05-09-2017, 12:14

I just free handed it.

**dscotthep** · 05-09-2017, 12:28

Originally Posted by MattK

...once you factor in the imprecision of cutting, rolling a hem, and sewing, it is close enough to function well.

This! I think people sometimes over-think their "cat curves". We're not building bridges or skyscrapers here. This is not engineering upon which countless lives depend, we're just trying to get the wrinkles out of our tarps.

**zekedoobie** · 05-09-2017, 13:42

I am in the process of doing this now. I use bristol board from the dollar store. I do verticle lines every 2 inches and plot the measurements using xtrekkers calculator. Then I cut the bristol board out and trace it onto my tarp. As was said above, it is often over thought but I like to be as precise as I can as it really doesn't take much extra time.
I figure my precision laying it out may help make up for my lack of sewing skills.

**jellyfish** · 05-09-2017, 13:45

I made a template that you can print and tape together. I'll upload it for you when I get home.

**Flatliner** · 05-09-2017, 15:09

I did the string thing on an 8' piece of hardboard. One side is my nylon curve (deeper) and the other is my poly side (shallower). 10 tarps later it's still going strong...

Sent from my iPhone using Tapatalk