Half Pyramid

[Jerry Adams]

I recently made this half pyramid:

Door is open, but can be zipped closed.

I like my pyramid tent but it weighs too much, so I left half as is and converted the other half into a triangle.

So, one side is 9 feet long by 4 feet wide, the other side is a triangle that extends 4 feet the other direction.

The design height is 48 inches, but it stretches to maybe 50 inches, I use a 53 inch pole so there's a small gap all the way around. This is the smallest height that works for me. My pyramid is 60 inches which is unnecesarily high so it weighs more and gets blown around by the wind more.

Tarp is 14.6 ounces including the zipper lock bag. Pole is 0.44 inch Easton – 53 inches long – 3.8 ounces. It would be perfect to use a trekking pole instead. Stakes are 2.3 ounce Ti. 21 ounces total.

What I like about this is:

all sides close to ground for better wind resistance

I can open the door totally or partially for ventilation if it's not raining and windy – not totally immune to condensation but about as good as it gets. If there is condensation the walls are steep so it runs to ground and there's enough head room (barely) to avoid touching walls when I lie down.

there's a triangular covered area to put my stuff

enough headroom so I can sit up – this is good if it's raining – I can sit under cover, fiddle with stuff, cook,…

I have tried various A-frame tents, hoop tents,… but I don't like these because I have to contort myself to get in, rotate feet around with dirt from my boots falling onto the sleeping bag. With a pyramid or this half pyramid I just sit down with my dirty boots in the "porch area", take boots off, lay down.

I might re-do it in Cuben which would save about 6 ounces so that would make the tent 9 ounces and total weight 15 ounces. I think I'll use this silnylon version for a while.

A lot of people consider a zipper something to be avoided, but I don't see it.

The two diagonal ridges are cat cuts 2 inches deflection. I should have had cat cuts for the zipper.

This is similar to Lawson's tarp and MLD Trailstar, but I like that I can close door totally with zipper.

[Adrian MITCHELL]

Looks great! do you have anymore info/pics on how you executed the apex of the pyramid? how does your pole stay up when the door is open?

Adie

[Eric Lundquist]

Fantastic! I've been lusting after a Duomid but can't justify the purchase just yet. MYOG is much easier to justify.

[Lawson Kline]

Awesome Design and Very Lightweight for the amount of coverage. I would be interested to see more photos.

[Jerry Adams]

Okay, couple more pictures : )

Obviously, anyone is free to copy this for personal or commercial use

Here's how I laid out cat curve. Sew the sides together with straight seam. Make a mark every 2 inches. Use the Roger Caffin spreadsheet to find the deflection for each 2 inch point and make a dot on the fabric. Sew through the dots:

I'm done making templates – don't like that anymore. Although if I made multiple copies of the same tent I might change my tune.

Peak detail:

I sewed the triangular side pieces together up to the peak. Get's a little funky right at the top. Set up tent. Cut a circle of silnylon. Hemmed it around the edges. Put one hand stitch for each of the 6 seams of the side triangle pieces. Made a gather in the circle so it conforms to the pyramid shape of the tent.

A long time ago I tried making a cone shaped piece, but why bother. Circle with gathers is easier.

Then I took down the tent and did two rows of stitches all around the perimeter.

Before, I made the circle of heavy Cordura nylon but I think this is unnecesary. The only thing is the pole may abrade the nylon inside and eventually poke a hole through. There are mulitple layers of fabric from the side seams so I think I'm okay.

Notice that the zipper almost goes to the circle piece. Next time I'll run it all the way to the circle piece. That solves the problem of what to do at the top of the zipper.

So, to sew on the zipper, take each side piece and mark a straight line. Then mark a cat curve line (mark every 2 inches, measure deflection and make a dot. Cut off everything but 1/2 inch. Fold over twice and sew to make hem. You want the edge of the fabric at the hem to go through the dots. Sew it to the zipper.

Other details are the same as pyramid tent http://www.backpackinglight.com/cgi-bin/backpackinglight/myog_silnylon_floorless_2-person_tent.html including the cat curve spreadsheet.

[Adrian MITCHELL]

thanks for that info

[David Passey]

Wow–nice shelter design. I would love to know the dimesion of the basic triangle you used to create the half-pyramid and the basic dimensions of the "door" panel. Very nice.

[Jerry Adams]

The rectangular sleeping area is 9 feet by 4 feet.

Any less than 9 feet or 4 feet wouldn't work because with the 53 inch peak height, the walls don't go up steeply enough so you have to stay at least a foot away from the edge before the wall is high enough.

With a 60 inch peak, you can get a little closer to the edge so maybe 9 feet is a bit more than necesary.

The triangular area is 9 feet long and goes 4 feet sideways

You can open either side of the triangular area depending on where your head is. Or where is best to put your stuff under cover or get in and out.

[Brian Barnes]

Great design Jerry! Well thought out, storm stable, light, functional. Captures much of what I look for in shelter.

[Walter Carrington]

That looks like a version of the Royce tent. There's a design in Horace Kephart's "Camping and Woodcraft", 1921, p86-91, available free online in pdf and ebook:
http://www.archive.org/details/campingwoodcraft00kephrich

The front vestibule extension adds almost zero to the weight of the tent (I have a spreadsheet someplace that calculates these tents).
Wind resistance is better than the usual vertical front of a half pyramid.
It's nice having a sheltered vestibule for gear.

I wish Oware would make a version of the Royce tent. It would take a very small modification of their alphamid.

I have an Oware nanomid in cuben that I bought in the BPL sale. I'm very tempted to add a little fabric to make it a Royce tent.

I made a double layered version many years ago that was partially successful.

[Ty Ty]

This is great. I have been reading and re-reading your 9×9 floorless shelter article but kept wishing it was slightly smaller/lighter. This would be just the ticket.

One thing I want to add is put a little strip fo maybe 1/4" velcro around the perimeter then make a removable bug netting perimeter for summer time.

I see myself making one of these very soon.

[Andrew F]

That's a really good idea… like a Solomid with a vestibule. Or a cross between a Duomid and a Trailstar. Very interesting.

[Mole J]

Neat simple design. Thanks for clearly showing so much info.

I have a Hex and an Oware 9×9, but was hoping to make myself a solo mid sometime. I was confused as to how to go about sewing the cat curves – sewing the straight seam first has cleareed things up for me.

[Rob Hubbard]

Jerry

Great work! I was Hoping to do something similar this year, though a bit bigger so my son could go with me. Will definately be bookmarking this and rereading it when the time comes.

[Ben Wortman]

That is sweet Jerry. I have been wanting to make one of that exact design for a few years. Your post I think will inspire me to finally get it going. I think this would be a superior design for 1 vs a normal pyramid. Maybe another variation would be to somehow use the basic shape of a shangri-la 2 (2 pole structure) and then instead of 2 long sides, take one and make it come to a point just as you have done here. That way, you could just use 2 trekking poles instead of joining them together on taller mid like yours. I'm not sure if that would be lighter or heavier. I'll have to draw one up on google sketchup and see. I am guessing that the one you made would be simpler to make just on the fact tht it only has one peak.

I also like your simplified cone. It looks alot easier than what I have done in the past.

[Jerry Adams]

Doesn't your trekking pole extend to 53 inches? or even 51 inches? That would be sufficient peak height.

Then you can leave your other pole next to you in case you get attacked by a bear or mountain lion : )

[Ben Wortman]

I guess I failed to mention that I would make it a little taller for me. I am 6'3" and like a little more headroom.

Another question: when I have made pyramids in the past, I have had a hard time keeping the straight sides at ground level. I stake out the 4 corners pretty tight, and when I raise the center pole, the midpoints of each of the 4 sides raise up a bit. I have tried staking the midpoints also, but it still was not the best answer.

I have never used cat cuts, so I am wondering if using one would solve this problem?

Any advice?

Thanks
Ben

[Jerry Adams]

I'm 6' 1.5"

To me, the critical thing about height is I want to sit on my sleeping bag and move around a little, cooking or fiddling with my stuff, and not have my head touch the walls

I have a longer than normal torso and shorter than normal legs so I think 51 to 53 inches is all you'de need

I also have a 60 inch pyramid and that seems overly high – so it gets blown around by the wind more and it weighs more

I think the cat cuts keep the walls more taught – they don't flap around as much in the wind – may actually make the sides go further up away from the ground

On my pyramid, I used to have tent stakes on the middle of the sides, but they are pulled at more of an angle by the tent so they sometimes pulled out in heavy wind, yet the tent stayed up just fine, so I removed them.

But the pyramid is wider, so my sleeping bag is further away from the side so it doesn't matter that it's flapping around in the wind more. I made the half pyramid narrower so I may need to stake the side down to keep rain splash off my sleeping bag.

I think it's fine for the sides to go above the ground a bit so there's more air flow to reduce condensation.

[David Olsen]

I hear you. I have that book and thought a little overlap/vestibule would work well.

Perhaps make some soon now there is interest.

[Ben Wortman]

Jerry
I may be missing something, but how wide was your fabric for the 2 pieces you used for the vestibule? They have to be wider than 54in correct? I assume that you did not use the actual width of the fabric, but cut it diagonally?

Do you know the disctance from the edge on the corner to the peak for vestibule?

Thanks

Ben

[Jerry Adams]

The two side panels are 54 inches wide, 67 7/8 inch long

The two end panels are 48 inches wide, 72 1/4 inch long

The diagonal between them is 86 3/4 inches

The vestibule pieces are odd triangles – 72 1/4 x 72 1/4 x 67 7/8 inches – the 67 7/8 length goes on the zipper – the seam between the end piece and the vestibule goes with the weave of the fabric. You don't want to sew the end piece along the weave to the vestibule that goes at an angle to the weave:

The vestibule requires fabric that is 59 inches wide.

All of these dimensions don't include the 1/2 inch seam allowance all the way around.

If I was going to do this in Cuben that is 54 inches wide, I'de make the side panels 53 inches wide and I'd have the vestibule as big as possible to still fit on the 54 inch Cuben. So, there'de be maybe a 4 inch gap between wall and ground. Trailstar works fine with a much bigger gap.

[Ben Wortman]

Thanks for the clarification. I happen to have 1 scrap of 60" wide silnylon 9' long and 1 scrap 54" wide 15 feet long. It is almost like fate that this thread popped up.

I don't quite get the part about not sewing along the weave. Can you explain this weave stuff a little more? Like how to know what way the weave is going, and how to orient it when sewing. I have never paid attention to it in the past.

[Stuart Allie]

I'm surprised nobody has pointed this out yet, but this is very close to a tarp version of the SMD Lunar Solo, particularly the new 2012 version. And Ron Moak has said that he is considering making a tarp version; i.e. a LS without the floor and bug netting.

That's not a criticism – I think it's a great design with a lot of potential.

[Jerry Adams]

"very close to a tarp version of the SMD Lunar Solo"

and as has been pointed out, similar to 1920s Royce tent

and pyramids have been around for a long time too – look at old Civil War pictures for example.

I just looked at the Lunar Solo – yeah, that would be nice. Probably not necesary to pull out the side a little making it a hexagon. Or maybe that would make it a little better in wind?

[Jerry Adams]

"I don't quite get the part about not sewing along the weave."

The fabric comes in a roll, 60 inches wide and however long they cut it off for you.

The threads in the fabric go in the "long" direction and in the "wide" direction. If you pull on these it will stretch a little differently. Ideally, if you sew two edges together, they should both be in the "long" direction or in the "wide" direction.

Edges that go at an angle, like the "zipper" or "ground" in my picture above stretch differently. You want to avoid sewing an edge that goes in the "long" or "wide" direction to an edge that goes at an angle. When you set up the tent it won't be as taught. There will be more wrinkles.

In the picture above, the edge labeled "end" goes in the "long" direction and should be sewed to the end triangle piece on an edge that also goes in the "long" direction.

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