Pyramid-style cuben shelter

[Rob van Dun]

Over the past weeks, I have been selling some “old” gear in order to replace it with newer and, more importantly, lighter gear. After some research I feel that I have little other choice than starting a MYOG shelter project in order to get what I want out of a tarp/tent. I am especially influenced by Scott van Doeselaar’s design (http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=22371).

Considering the fact that I am 6’4 tall I opted to go for a duo pole design in order to maximize usable floor area and avoid brushing against the walls. Basically, it is very similar to the Shangri-La 2 and will be a cuben shelter. I was extremely satisfied with my old Hex3 and prefer 360 degree protection over a tarp.

After reading different opinions and theories on how to connect the laminates, I’ll most likely glue the cuben, rather than sewing it in order not to weaken it and it seems some other users have good experiences with Aqua Seam.

I hope you can give me some feedback about the design below that I have in mind. Like I said, it is very similar to the Shangri-La 2 and I want to do it in 0.6 oz cuben (the 21 gsm cuben of a European supplier).

Looking at the Shrangri-La 2 and MSR Twin Sisters, they opted to go with two V-like seams along the long wall of the shelter, where the side stake-outs are. Would this be necessary or would a single piece of cuben be enough with an reinforced stake-out in the middle?

Furthermore, I want to apply a 0.7 oz no-see-um perimeter on three edges and creating a mesh door to create a fully enclosed shelter (when coupling it with a GG polycro groundsheet).

For reinforcing the stake-outs I want to use a double layer of 0.6 oz cuben, similar to Scott’s design. Likewise, I want to connect the cuben and no-see-um by simply glueing a second layer of cuben over it and thus sandwiching it.

Oh and yes, I wasn’t able to create a catenary cut in Sketch-Up, but that should be applied as well!

Including no-see-um (0.7 oz/sq yard) I strive to achieve a weight of 11 oz!

Thanks in advance for your advice and all those cuben related threads on this forum!

[Dan @ Durston Gear]

I would bond your shelter with a double sided tape rather than a glue. Glue is handy for small stuff like reinforcement patches, but it's extremely time consuming to work with for longer seams, messy and it's hard to get it to dry properly. That's why all the companies that sell cuben gear use tape rather than a liquid adhesive.

Have a look at these tapes. They all should work well, but the 1" wide 3M tape is supposedly a great one.
http://search.sailrite.com/?freeText=seamstick

[Rob van Dun]

Hi Dan,

ExtremTextil, the European supplier indeed advices to use the 3M tape, rather than glue. For the longer stretches I guess it would work better, in small pieces. Thing is though that I would like to add a netting perimeter in the folded over seam at the bottom, that seems really hard to do to me with tape.

[Rog Tallbloke]

For the SL-2 and twin sisters tents which are made from trad nylon, the seams from pole tops to mid-point guyouts make sense, they reduce stretch when the wind hit's the long side. Cuben doesn't stretch much at all before it fails, so whether you'd consider reinforcing those stress lines from pole tops to guyout worthwhile would probably depend on the amount of force you think the CT2K.08 material will take. I plan to put some 5mm shock cord into my midpoint tieouts to prevent shock loads ripping the cloth.

For the netting, I'd consider just tacking it on with silicone higher up inside the tent where rain can't blown onto it and wick down to your groundsheet. Then you can just pull it out in winter and leave it at home so snow doesn't freeze into it.

[Dan @ Durston Gear]

I would try to tape everything I could. Around the bottom I would 'hem' the shelter by folding the cuben once using tape. Then I would sew the netting to that, or I would skip the bonded hem and just use a sewn rolled seam to attach the netting. Either way, I would use the tape as much as you can, glue where you can't tape and sew where you can't glue.

[Rob van Dun]

Thanks for your feedback guys.

@Rog, I did read about the silicone adhesive in an Hex3 thread this week and your suggestion to do it the other way around next time yourself. While I don't hike alot in the winter or snowy conditions, it still seems interesting as a sort of quick and dirty method (no offense) and requires no sewing and a light solution as well. Would it be durable enough for longer usage, assuming the netting will not take that much tension.

Furhermore, about the V-like seams from top to middle guy-out, I get what you are saying. Like you said, cuben doesn't strecht that much and therefore I wonder whether such a feature would add much resistance in higher wind when it's pitched lower to the ground. Interesting idea to add shock-cord, but I must say I do not quite get what that would look like (read: how exactly are you gonna apply that)

@Dan, I go with the 3M tape for the hem and connection of different cuben panels for sure. The guy-out reinforcements (triangular) can be done in similar fashion I suppose. That leaves very little connection to be glued. Maybe the hiking-pole cups on top due to their positioning across three different panels, the zipper and mesh for ventilation.

Kind of odd maybe, but I wanted to attach a full netting door from top to bottom with a sloping angle from 12" behind the cuben door and towards the top that would have a door as well. I am still not entirely sure if this actually is going to be that more effective than just a perimeter along all of the walls though. Especially given the additional weight. I thought it might be neat for extra ventilation in dry weather and additional bug protection. However, those bugs are unlikely to march in during wetter conditions when opening the front door for a short moment. Any thoughts on this?

[ziff house]

C:Documents and SettingsOwnerLocal SettingsTemporary Internet FilesContent.IE5JU4RRYTIBasting+Tape+Selection+Tips[1].pdf

This is from 3M adhesive tape , note ''has a tendency to slip apart in strong sunlight'.
I would be willing to get a roll and experiment though.

[Lawson Kline]

Here is a similar design that I built. Its 108" long x 54" wide and uses CT2K.08. I am pretty sure it came in around 8.5oz done but its been a while since I last weighed it. I had it set up for over a month and the thing doesnt even budge in high wind.

Promotional ad that was on my website for a month or so..

[Rob van Dun]

Wow Lawson, that looks fantastic and great to hear about that performance as well! 8.5oz is insane imo. When adding a little netting it will be just about 11oz for you design. I would want mine a bit bigger though.

[Lawson Kline]

Hey Rob,

Thanks for the feedback as well as the PM. I was going to shoot for an under $400 price point ($350 Intro Sale) but there was absolutely zero interest in the shelter whatsoever. The lack of interest really surprised me since it would of been the worlds lightest 4 season shelter. Actually it would of been the worlds lightest 4 season shelter that never sold a single model haha.

As far as construction tips goes… I would suggest using a double sided 1/2" tape and the CT2K.08 material. 54" is as wide as you can go unless you join two piece of material. The ends have vents which really help for keeping it livable even in the summer. I am not sure if you need the extra length but it never hurt's to have extra space. If you camp with another person and you both use trekking poles you can set the poles off to the side which really opens the space up. Anything else you want to know please feel free to ask.

[James holden]

god i need to get myself a mid …. sigh

[Henk Smees]

Hi Rob and Lawson,

This looks great. If you are going to exchange information on this project, please do this here – if you don't mind. It really helps other DIY-ers.

Personally I'd be interested in seeing some detailed pics on the vents of Lawson's design. Once again…. if you don't mind :).

[Rob van Dun]

Lawson,

Zero interested, that really surprises me actually. Ofcourse, many would rather use a tarp, but what about all those users that are used to have 360 degree protection. The asking price isn't that high either, comparing it with some other mids (Zpacks, MLD). 108" is just 6" short of what I wanted to go for and that seems long enough too.

I am going for the CT2K.08 indeed and will be using 3M 9485PC (10mm) tape for the majority of connections.

I don't see why 54" would be the biggest width I could achieve, given a height of approx. 110cm. The 145cm I currently have in mind results in walls that have a height of 132cm which is just the maximum I could achieve imo (given the hem and seam at the top).

In your design though I do not see any seams at the 4 corners on those pictures! Did you use two pieces which you joined in the middle of the front- and backside of the shelter? Moreover, you didn't use a zipper as well?

Henk, I am certainly going to post the whole process online when I completed the shelter.

[Steven Evans]

but there was absolutely zero interest in the shelter whatsoever

I saw this in one of your geal deal posts and I was actually waiting for it to be released. I'll buy your prototype today if you want. Love that thing!

[Karl Gottshalk]

Lawson, I can't believe you didn't get any interest in your 2 man mid, they look perfect to me!

[Lawson Kline]

Hey All,

I was quite surprised considering the 8.5oz weight, 4 season usability and price. I probably should of made them available to the public before abandoning the project but BPL users always seem to give me the best feedback and since I received very little feedback, I thought the product wasn't a great idea. Maybe I will try for a small production run now that there seems to be some interest.

Hey Eric,
Shall I put your name on the waiting list? haha :)

Hey Henk,
I will work on getting some construction photos online including the vents.

Hey Rob,
The MLD Duomid in cuben is 12oz and $405 so it would be very competitive with that shelter. I have never seen a duomid in person but I think its probably a little wider and has a taller peak (I think its 58"). You need a shelter thats wider and taller with a single pole design otherwise the shelter wouldn't have alot of usable space due to low sloping walls. The nice thing about a double pole mid is the overall height is lower which really helps to shed wind and the walls are steeper which is great for shedding snow and giving your shelter a ton of useable space. Don't get me wrong both designs have their pro's and con's but overall I think a dual pole mid is a much better design for rough weather.

As far as 54" wide goes you can go wider but in order to do this you would either have to have a middle panel seam or you would have to lower the shelters overall height. I am not quite sure on the exact height on my shelter since I usually keep the edges off the ground but I want to say I set my trekking poles to about 125-130cm which is around 49"-50". I put the tips in the ground with the handles up so they do penetrate the ground by about 2-3" depending on soil type. I find the height to be perfect. You could go shorter due to the really steep walls but you would loose some of the shelters usable space. I have a Black Diamond Betalight and I like my shelter better. It pitches tighter and doesn't flap around like the silnylon.

As far as seams goes every hip/corner ridge has a 1" lap seam. The 1" seam is really overkill and makes it hard to pitch super tight. I think its the reason the corner hips/ridges look seamless. I would suggest using a 1/2" seam on everything. I started off using 1" seams on all my ridge lines and lap seams but have sense switched to 1/2" lap seams and ridge lines. Extra strength can be achieved by adding a clear hi-tack one sided strapping type tape. Let me know what else your thinking in regards to questions or feedback.

Hey Steve,
I don't like to sell my prototype's since they are usually a bit rough in appearance and plus I usually set them up for months at a time to make sure they are built to last. So essentially you would be buying a shelter that has seen months of exposure and is quite used. If you are interested in a production model I will put your name on a list with Eric :)

Hey Karl,
I am with you on the lack of interest in the design. Who knows maybe this forum will generate some interest. If BPL wants one to test I will send them one for a review. Problem is I have had a hard time getting them to look at any of my gear. Gear the public has seen and gear that is "top-secret" potential products.(cuben hammock/tarp was the only exception but it was a failure so it really doesn't count)

[Rob van Dun]

Hi Lawson,

I totally agree about your view on the duomid, usable space etc, that's why I wanted to go for a double pole design in the first place. Since I thought they weren't on the market yet, I felt the need to make one myself. Now, I would very much like to make one myself and expect it to give a great amount of satisfaction after completion. Otherwise, I would be very interested in the shelter as well. I think I would be better of speaking price, time and aesthetics if I would just buy one though:)

Thank you very much on the info on the corner seams, the width of all seams and all other sorts of tips on your design. Since the designs are basically identical (except a 6" difference in sizing), this feedback gives an amazing amount of confidence in the design, especially since you've already tested it for over a month.

According to my calculations, the 145cm is exactly the max size I can get with a minimum height of 110 cm, pitched right to the ground. This results in a cuben-height of 132cm, leaving 2" for seams.

Some more questions/feedback as you seem willing to share:
– I can't really see, do you have a zippered front door?
– It seems to me that you did use grommets for the guy-outs, how did you reinforce those sections?
– what material did you use for the cover of the vents?

I am getting pretty psyched to start working on that project!

[Dan @ Durston Gear]

"BPL users always seem to give me the best feedback and since I received very little feedback, I thought the product wasn't a great idea."

Maybe this shelter was perfection, so no one had any suggestions for improvement :)

[drowning in spam]

Lawson, I thought your plan was to test it over the winter and make it available sometime next year. I remember you talking about leaving it up in the mountains to test its snow load capability and using it with a snow jack. I'm not in the market for a new winter shelter this season, but it's something I'll seriously consider next year. I was and am still hoping that your shelter will still be an option.

[Lawson Kline]

Hey Rob,

There is no better feeling then using your own gear. I think this is a pretty straight forward shelter to build so you shouldnt have too much trouble as long as you use a tape and not an adhesive for the seams.

The front door is zippered and has a storm flap. I was thinking of using velcro to keep with the 100% bonded theme but I wasn't sure if that was a good idea or not? I used spur grommets which have held up fine. I use the same spur grommets on my tarp tie-outs and they have all held up great. I laminate two pieces of CT5K.18 together on the bias (0,45,90,45) giving you a hi-bias corner patch and then bond the corner patch to the tarp using a special bonding method I came up with after lots of testing. (Tape, Contact Cement, or Hysol works great but its not what I use).

The vents used a CT3.5K.18 but next time I would use a CT2K.08. I rolled and bonded weed whacker string on the end to add some edge stiffness. The vents have a 6" hole in the front and back with a piece of mesh bonded between the two materials. The vents are a pain in the ass to build and next time would make them simpler. (not sure how though)

Hey Dan,
I never thought of that. Maybe alot of lightweight backpackers are not 4 season campers? I am but I live in Florida so that really doesn't count haha.

Hey Eugene,
That was kind of the idea. I would of loved to sell them this winter but I still never got one on top of a Mountain for a serious winter storm with lots of wind and snow. I wanted to send one to someone that lived near a exposed ridge but no one offered. I was thinking of strapping it to the roof of my truck and seeing how fast I could go before it torn apart. My guess is 80-100 mph.. A while back we had a storm with 40+mph winds and it didn't even budge. I hung out inside it for a few hours just to see what kind of stress it was being exposed to. I think it could of easily handled twice the wind and maybe even more.

[David Chenault]

Both the theoretical shelter and Lawson's job look sick. Making big stuff like that isn't my balliwick, ya'll have my respect for sure.

Lawson, if you need someone to do snow and wind testing, let me know. (Seriously.)

[Lawson Kline]

Hey David,

What kind of testing were you thinking?

[Rob van Dun]

Okay, so I've ordered some CT2K.08 in Europa, with some additional nano-see-um, shockcord, zippers etc.

I wasn't sure about the no-see-um skirt around the perimeter, so I had some thoughts on that over the past week. Result is that I will go for a bottomless bugbivy.
I will be using the GG polycro for groundsheets whether there are bugs or not. In order to save weight and €€€ (by not using a cuben fiber floor), I am pretty sure that I will make a 2person bugbivy in order to have a versatile setup.

The lenght will be 215cm and it will be tapered from 120 to 100cm in the back. The height of the front will be 90cm and sloping down to 50cm in the back.

At the four lower corners I will reinforce the nanoseeum (0.7 oz/sqyd) and attach shockcord that connects the bugbivy to my four corner stakes of the tarptent. As I will be using either 2 or 4 hiking poles, there need to be two holes at the top which will be reinforced and match the thickness of standard poles. Furthermore I will attach shockcords and tent fasteners to attach the peaks with the wristcords on my hiking poles to elevate the bivy from inside out. This will be necessary as the YKK 3C zipper will be on top of the bivy, between the two peaks. I noticed that MLD's bugbivy uses the same method by the way.

By coupling it with the groundsheet and some guylines, the bugbivy can be used as stand-alone module as well. Whether using it inside the tarptent or as bugshelter, it will have six guylines that secure it. By using the polycro groundsheet this will create a sufficiently enough bugshelter. The polycro can be folded along the edges of the bugbivy in order to create some sort of bathtub and not allowing the creepy crawlies in.

Talking weights now
I will use approx. 5m² of 25 gsm noseeum= 125g (4,4 oz)
6 Guylines: 1,25mm Dyneema approx. 8m total length= 10g (0.4 oz)
2 Tent fasteners= 1,5g (0.05 oz)
One 120cm YKK 3C Zipper= 15g (0.5 oz)
Reinforcements 6x= 24g (0.85 oz)

That totals 176g (6.2 oz) excluding stitching. The two person bottemless bugbivy will be around 7oz!

Any ideas on this idea as well?

Kind regards,

Rob van Dun

[Rob van Dun]

It's done, it took me some time and effort, but it is standing in the backyard now. It is currently snowing, so I'll see how it holds up. I will post more and better pics in a few days.

[Ken Thompson]

Looks real good! The colored cuben has me changing my idea about that fabric. Could be a problem:)

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