DIY Hexamid Help

[Matt]

I need to replace my Z Packs hexamid and would like to make my own.  I don’t mind saving money, and I really enjoy making my own stuff when it turns out well.  I downloaded what seemed to be a nice hexamid design, checked all the math, diligently made a prototype, and thud … the prototype sagged and had less usable room than advertised.  Thank goodness it was made out of a Walmart blue tarp.

Can anyone put me onto a tried and true hexamid design?  Alternatively, can anyone convince me that making shelters is much more complicated than packs and sacks, and a likely cash sinkhole?  Or is this just a hexamid thing?

[Sam Farrington]

Have made both, and tents are much harder for the reasons you may already know.  A good way to begin with tents is to mod a super design by making it much lighter with lighter materials.

https://backpackinglight.com/forums/topic/81307

But decided long ago not to mess with DCF construction, though am not going to get into the fray about DCF vs other materials..

[Matt]

I thought about deconstructing my ZPacks hexamid, and then creating new patterns from the pieces.  But the wrinkled fabric and the taped seams convinced me otherwise.

As I look at my paper models, the hexamid is nothing but a bunch of flat triangles, joined together along the edges, and then pulled together to form a peak.  It feels like some sort of math equation ought to be available to create the desired height, footprint, and wall angle.

Don’t even get me started about Sketchup.  After 3 hours, I still failed to draw the first triangle.

Humbled, but not deterred!

[Jerry Adams]

I would think making packs is more difficult because the fabric is thicker and harder to sew through, tight spaces you have to manipulate to get a seam where you want it.  Easy to “paint yourself into a corner”.

Having catenary curves helps.  Is that why it was sagging?  You can’t really do that with a blue tarp.

Maybe when you get the size you want with the blue tarp, make a version with the cheapest nylon and do cat curves.

You can make tent without cat curve.  Just do the first row of stitches of flat felled seams.  Erect tent.  Halfway between top and bottom squeeze out with your fingers how much cat curve deflection is good and measure it.  Then lay out cat curves with that deflection and finish flat felled seams.

“Alternatively, can anyone convince me that making shelters is much more complicated than packs and sacks, and a likely cash sinkhole?  Or is this just a hexamid thing?”

No, it’s a likely cash sinkhole.  Probably spend more money when it’s all over, than if you just bought stuff.  Probably not a good idea to make stuff yourself unless you like doing it.

[Lester Moore]

It feels like some sort of math equation ought to be available to create the desired height, footprint, and wall angle.

You can use trigonometry formulas and a spreadsheet to enter whatever height and footprint you want and the formulas will calculate the straight side lengths of all the panels for you. It helps to assign each panel side and other key measurements a unique letter name on your spreadsheet to keep all the formulas easy to follow. After you calculate the panel sizes, you can make a 1 inch per foot scale model out of craft paper to make sure everything lines up and fits together properly. Cat curves would require you to modify the seam line position a little after you cut out the panels. This process worked pretty well for me making my first partial solid inner net tent.

[Matt]

To the protractor!  Thanks Lester.

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