5-Sided Pyramid Tent – Almost Done

That looks really well done. All the panels are tight – so you laid everything out and sewed it well.

I think that 5-sided design is really good for one person – smaller so it weighs less. I don't think anyone else makes something like that.

Thanks, Jerry! I referenced your MYOG article quite a bit for making this. Your half-pyramid tarp also provided the beginning inspiration for this design.

The basic rectangular footprint is actually just a little bigger than a MLD Duomid. That 5th panel just provides a vestibule, some additional headroom on one side of the pole, and will allow for drip-free entry over the sleeping area. I considered making it a 6-sided design (this would add approx 1 oz), but I went for the smaller footprint.

I'll be using it with my 60-lb dog. Hope to have it ready for a week-long trip in the Sierras I am going on soon.

After using this tarp, I've found the catenary curves to cut into the usable interior space too much. In particular, the vestibule is smaller than I wanted. The tarp is still usable for fair-weather trips, but it's not the foul-weather design I was hoping for.

So I plan on making a larger hex tarp (similar to the GoLite SL3). A couple questions:

1. How much deflection in the cat curve would be recommended? I'm thinking 1 – 1.5 inches
2. Is a #3 sipper too small to use for the door? I will be probably be doing a straight zip up the middle of one panel.

1.5 inches probably good. Not real critical. Yeah, if you do too much the space inside gets smaller. If you do too little it's harder to get a tight ridge.

I used #3 zipper on tent for many trips. It finally started unzipping itself in the middle. Good it didn't happen in bad weather. I replaced with #5 zipper. I think that's best. #3 is fine for sleeping bag or jacket that doesn't have a lot of sideways pull on it.

Thanks, I will go with a #5 zipper then.

I actually found the 3.5 inch deflection to be okay (or just a little too much) at the 90 degree corners of the pyramid tarp (where the fabric changes direction by 90 degrees). But when changing direction by less than 90 degrees, the 3.5 inch deflection was way too much. Maybe 1.5 inches deflection will be a better balance.

That is difficult to figure whether to do catenary curve on odd cases like that.

I have the zipper on a ridge. Didn't put a catenary curve and it wasn't tight so I re-did it with catenary curve.

The two ridges farthest away from zipper have a catenary.

The two ridges closest to zipper have no catenary. That sounds consistent with your experience.

Looks pretty good. Is there any reinforcing fabric at the peak/apex? You might want to sew some heavy duty fabric where the pole goes into.

The photos above are from my first pitch (before I added in peak reinforcement of 210D Oxford).

> Is a #3 zipper too small to use for the door?
How careful are you?

I use #3 coil-coil plastic zips on both my summer and winter tents. Straight-line runs ONLY. Never has any problems with them.

Cheers

John, that is a great dog. It has the act figured out just like Franco's cat. I think they all earn union wages.

–B.G.–

The problem with #3 on a tent, is if there's a lot of sideways force when you zip and unzip. Or maybe from wind.

#5 doesn't weigh that much more

But, I used #3 for years before it finally failed. Any zipper will eventually fail.

I'm making progress on my Hex. I just finished sewing the main ridgeline seams and hemming the bottom edges. I decided to try using Argon silnylon – the material seems plenty waterproof from my bathtub test.

I have a couple questions about reinforcements:

For the main tie-outs on the perimeter of the tarp, is 1 additional layer of silnylon enough reinforcement? I plan on using 1/2'' ribbon, probably stitched with an x-box.

For the peak reinforcement, should I stick with 210D Oxford? Or would multiple layers of silnylon be preferable? My line of thought is that transferring the load from a fabric that stretches (silnlyon) to one that doesn't (210D Oxford) could actually be weaker than using a couple layers of silnylon. The only problem is that silnylon lacks abrasion resistance. I plan on always putting the handle of my trekking pole at the peak.

For tie-outs, I sew the 1/2" webbing to the flat felled seam of the ridges. There are 5 layers of fabric there. I just do a zigzag spaced at 1 mm. The goal is to have no two holes through the fabric closer than 2 mm. Actually, I do a reverse straight stitch to lock thread, then a forward zigzag, then another reverse straight stitch to lock the other end of the thread.

I've also just sewn it to the hem at the bottom edge – folded over twice so there are three layers of fabric. Reverse, 1 mm zigzag, reverse. But that was like in the middle where it doesn't get as much stress as the corners.

I've used 210 D Oxford, Cordura, and just one other layer of silnylon for peak reinforcement. I don't think it matters. So you'de have 210 D Oxford on the outside, and silnylon on the inside. The handle would go against the silnylon which would provide more than enough abrasion resistance. The 210 D is less stretchy so would take most all the load, which would be transferred to the silnylon around the perimeter at the bottom of the reinforcement.

I have never seem any ripping out of any of that. I try to be sheltered, avoid mountain tops where it's windiest. But I get pretty windy sometimes.

"For the main tie-outs on the perimeter of the tarp, is 1 additional layer of silnylon enough reinforcement? I plan on using 1/2'' ribbon, probably stitched with an x-box."

One additional layer of silnylon. Fold the hem over twice. Sew tie out onto the hem with two loose bartacks. Done.

Ryan