Feb 26, 2011 at 5:57 pm #1269779
I need a pyramid tent for four people for hiking in Alaska this summer. Since two of us share a quilt we need enough room on either side of the center pole. I'm wondering how large a pyramid I need.
The silnylon I purchased is 60 3/4 inch wide, so following the standard design I could make the pyramid sides about 2 x 59 1/4 = 118 1/2 inches wide, accounting for 1/2 inch flat-felled seam allowances (one where two triangles meet to form a side, and two more where two sides meet at a corner ridgeline).
Is a pyramid with 118 1/2 inch sides large enough for four people? I plan to use a fairly large pole, 75 inch (7.5 ounces, left over from an old tent), or joined trekking poles when I want minimum weight.
If not, I can see two ways to make the sides larger, and am interested in feedback and other ideas. My concern is how the stresses distribute themselves along the sides and seams under wind load.
One way is to cut the largest right-angle triangles possible out of my fabric, then add a long, thin filler piece between them to make one big (isosceles) triangular side. From one corner the side would be made up of a triangle, then a filler piece, then another triangle. There would be no vertical seam running down the center of a side, instead there would be two parallel seams maybe a foot apart straddling the center line of a side.
Alternatively, I could cut large clipped triangles (corners missing), then add small triangles to make up the corners, yielding large, complete right-angle triangles, then join these to make the side. From one corner you'd see a small filler triangular corner, a large piece, another large piece, then another small filler triangular corner. Here there would be a vertical seam down the center of each side, and two small vertical seams near the corners.
Kindly send me your thoughts on required size and how best to proceed.Feb 26, 2011 at 6:25 pm #1702041
@footeabLocale: Pacific Northwest
Since this is a two person design using 1 quilt, you should have 4 available trecking poles. Yes? This opens up a huge number of options… Slightly harder to setup though, but it would make ingress/egress much simpler. AK, using bug mesh on sides I hope, otherwise the mosquitos are going to drive you batty. Just ask the Cariboo.
I forsee something that looks more like a squall 2 from Tarptent for two persons.
The other designs I forsee is something more like the betamid with two poles where you sleep between the two poles even though the other direction is longer and don't roll around in your sleep! Or have to get up and go to the bathroom in a hurry either!Feb 26, 2011 at 6:42 pm #1702049
Did you see the article I wrote?
And Chris' several threads including http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=42299?
He made pyramid just that size for 4 people, but I don't think he's used it yet.
His tent looked like it came out really good.
Be prepared for the possibility the first one you make won't be so good and you'll want to do version 2 after you've learned technique.
Golite makes a pyramid 114" square that they say would fit 5 people – 4 across plus one person cross ways, so I think your 118" would work for 4.
It would be pretty cozy though. Did you say two people would sleep under the same quilt? Then I think 4 people would be just fine.
If you chose to make it bigger, either of the ways you mentioned would work equally well. I've done that before. Sew together two pieces of fabric together to make the larger right triangle piece. Be really careful the edges are perfectly straight and going straight along the fabric so that when you eventually pitch the tent the sides are taut and even.Feb 26, 2011 at 6:46 pm #1702053
On looking at your post again, I would do the alternatively method.
What Brian said is good too, so many choices.Feb 27, 2011 at 4:21 am #1702146
Rod LawlorBPL Member
Check MLD's site. Ron has abandoned the equal triangles for a large lower panel and a smaller top panel. It opens up a heap of possibilities for size.Feb 27, 2011 at 7:40 am #1702175
I didn't see what you meant at MLD site. Is there a particular tent you're talking about.
One thing about a simple pyramis, is that the 8 pieces (right triangles) are the same size so it's easier to calculate, lay out, and sew. And it makes a very effective shelter – headroom, big enough floor areaFeb 27, 2011 at 8:09 am #1702189
If you take a look at the MLD Supermid, you will notice that the side and back panel (opposite the door) are joined to the top of the tent with a horizontal seam. There are no mid panel vertical seams on the tent. It's an interesting design and I've read several trip reports that seem to prefer the strength/structural integrity of this design.
You make a good point about the equal size panel easing the construction process. I hope to create a 1.5 person mid (Duomid size) and a 2.5 person mid (similar but smaller than Chris's recent creation) so I've looking carefully at all the designs. Thanks the feedback you've been giving on the other threads about the mids, they have been very helpful.Feb 27, 2011 at 8:20 am #1702200
I see what you mean
I've noticed that
It does eliminate a lot of seams
You wouldn't be artificially limited to a base that's 2 x 60 inches
It would actually be easier to lay out because there are only 4 big pieces. Actually 5 when you count the door side.
You wouldn't waste any fabric – alternate the big pieces with the two door pieces on each end.
Good idea.Feb 27, 2011 at 10:06 am #1702240
Thanks for all the comments, please keep them coming!
Brian: You've probably gathered by now that I need a 4-person pyramid. But only two of the four will share a quilt. Intriguing idea about multiple poles, but maybe for the next one, as I need to get going on this one soon. And I am planning to include a noseeum skirt around the perimeter, with little bits of cord spaced along the pyramid edges so I can tie the netting up when I want maximal ventilation.
Jerry: Your article inspired me to build the pyramid, many thanks. I didn't know what to do for Alaska until I read it, so it was particularly timely for me. I've probably read it three times by now, along with Chris' posts and his web site, more than once if I recall. Over the years I've built many tarps, quilts, net tents, wind suits, parkas, insulated vests, etc, so I'm pretty experienced. I think I will make it bigger (maybe 132 or 144 inches, not sure).
Rod and Mark: The MLD design is intriguing. And it should be easier to get the sides larger than 2 x 60 inches than with my "alternate" design, as Jerry notes. I may go this route…I'll post pictures when it's done.
Thanks again for the many good ideas, don't stop now!Feb 27, 2011 at 2:06 pm #1702334
@owareLocale: Steptoe Butte
You can add side walls to any mid to make it larger.
Also you can put the poles on the outside if you lash them together to form a scissors
shape.Feb 27, 2011 at 4:04 pm #1702366
kevin timmBPL Member
@ktimmLocale: Colorado (SeekOutside)
Sidewalls of a few inches add a lot of use able room. We do that on our Tipi's basically with a sod skirt
As far as sizing it depends if you barely want to fit 4 people or fit four comfortably.
9 by 9 should fit four, but a bit tight if you pitch to the ground.Feb 27, 2011 at 10:14 pm #1702524
Hope to use this information soon on our next trip :)Feb 28, 2011 at 2:53 am #1702553
@footeabLocale: Pacific Northwest
yea, with 4 people that is why I stated the beta mid. I might have the name wrong though. It sleeps 3, claims 2 and has 2 poles in the central region for a double peaked "tarp" design if you set it up correctly. Made by Black Diamond. I have camped under it with 3 before. Make it bigger for 4 and viola. Obviously the BD betamid sleeps lengthwise beside the two poles whereas you would be changing it and probably move the door 90 degrees as well.Feb 28, 2011 at 9:33 am #1702622
Chris RoaneBPL Member
@chrisroaneLocale: North Rockies
I'm pretty sure a 9.83'x9.83' pyramid would fit four people without a problem. I haven't tested my 10×10' pyramid's, as far as how four people would fit yet (I'm hoping to do that later this week), but based on my eye balling things….this is a great size for four people (with gear).
If you go away from the simple 8 piece design, you not only add more time putting things together, but you also add more of a possibility for human error. But it sounds like you are more experienced than me with this stuff, so this may not be a factor.Mar 1, 2011 at 6:42 pm #1703248
I'm now convinced the MLD design, triangle on top of trapezoid, is the way to go. Less seams, ability to make the pyramid any size you want, etc.
From earlier responses it seems that a 10' pyramid would be spacious for three and adequate for four people. An 11' pyramid likely would be spacious for four and adequate for five. Since I prefer spacious lodgings, room for cooking and drying stuff, etc, 11' seems better.
Now I occasionally need lodgings for five or six. My calculations show that a 12' pyramid would only weigh 3 3/4 ounces more than an 11' pyramid based on 1.4 oz/sq-yd fabric. I'm now thinking to go with a 12' pyramid, probably spacious for five and adequate for six, but for four it would be like the Taj Mahal. I will also use it for car and kayak camping.
Am I crazy? Is a 12' pyramid an unwieldy monster? Oware makes an 11' pyramid, but with a 7.5' center height…
Other details: the MLD-style vent at the top looks simple enough, and I like the MLD door design. For the large size I think I might include two tie-outs along the edge instead of just one in the middle.
Thoughts? Advice? Warnings?Mar 1, 2011 at 7:07 pm #1703265
Ron BellBPL Member
If you get it up to 11+ base length consider inverting the triangle seam from the top to the bottom. (Horizontal seam is low instead of high.) Check out the Circus Tent pics. That would allow a convenient height seam to insert reinforcement pull out triangles.
Another tip is to install a beefly web loop in the apex and then a vertical internal guyline can be tied from the apex to the center bottom side tieout as an internal support for high wind. On the Circus Tent a V can be formed inside thus tying the two peaks to the bottom center creating three virtual supported side panels.
– Always flattered when DYI'ers can use the MLD particulars for project…But I predict this design will become very common ;-) Another advantage to the shorter horizontal seam top triangle design (Like in the Solo, Duo and SuperMids) besides the strength is the shorter seam requires less seam sealer thus saving more weight.
-RonMar 1, 2011 at 8:54 pm #1703302
The weight might not increase much going from 11' to 12' per your calculations, but the area needed to setup the mid sure will. That is more than 20 square feet added to an already huge mid. For summertime use, I'd start to worry about being able to find large enough areas that allow each corner to be pitched flat along the same plane.
Also, you probably already considered that changing the base dimensions without increasing the height lessens the amount of new space that is usable due the more acute sidewall angle. Might not be worth it for summertime use with small gear loads. Looking forward to your project.
Some great suggestions from Ron above. I've been lurking a very long time here and it's always nice to see manufacturers of great gear weigh in with expert advice.Mar 2, 2011 at 6:33 am #1703394
Chris RoaneBPL Member
@chrisroaneLocale: North Rockies
When you are looking at these designs keep in mind how much room you are going to have around the door area (the opposite end of where heads will lay down). That is why I would consider a 10' pyramid a Taj Mahal for four people. This is enough room to cook in and hang out when it is raining. And the fact that it is floorless makes it even more practical with these applications.
If I wanted a setup that would handle six people, instead of building one big one, I would probably build two 9.5' or 10' pyramids.Mar 5, 2011 at 4:51 pm #1704907
You've all convinced me that 12' is a tad large, so I'm going for an 11' base. Also, with a 90" pole height the lower trapezoid and the upper triangle are not that much different in height, 60" vs 50", so it doesn't make that much difference which one is taller.
But I'm not sure about the center height. Oware's 11' pyramid has a 90" peak, but you don't lose headroom very fast as you lower the peak height. E.g. you get 106" of width at 1.5' wall height for a 90" peak (wall slope is 54 degrees), but 98" of width at 1.5' wall for a 70" peak (wall slope 47 degrees); the wall fabric weighs 4 oz less, but for 4 people I'm not worried about 4 oz. The fractional area loss as a function of headroom does increase as you increase the headroom, though (e.g. at 4' height you get 62" width for 90" peak, and 42" width for 70" peak).
What are your thoughts on the tradeoffs between tall and not-so-tall peak heights w/r/to useful area and other things (wind resistance, stability, etc)? Currently I'm tempted to go with a 90" peak.
BTW, I'm very impressed that Ron from MLD has been making useful suggestions based on their designs. I sometimes feel odd when I copy commercial designs, like I'm stealing from them, but this is of course silly. From what I've seen the MLD design is the best out there, and if you're going to steal ideas, you might as well steal from the best! Many thanks, Ron.
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