Oct 31, 2010 at 8:37 pm #1265000
Came up with a list of requirements for a solo tent, along with a model, that you may find useful:
> Minimal, competitive weight
> Adequate room – length, depth and height, for 1 adult and child or pet
> Ventilation and netting sufficient on all sides and overhead to minimize and protect from condensation
> Room for storage and cooking, fully accessible, but separate form living area
> Entry and exit without crawling or obstruction by gear
> minimal pole length for ease of setup and low weight
> Freestanding – not dependent on stakes for support or shape
> Minimal obstructions on canopy surface – sheds wind, water and snow
> Minimal vertical and horizontal canopy surfaces – sheds wind, water and snow
> Strong, rigid but flexible frame
> Tent pitches taut, and remains so
> Pitches from outside without flooding floor
> Fabric does not sag once taut, and is reliably weather and wear resistant
> Entry and exit without flooding
Began with stability, and came up with the following model:
> The darker piece is the floor outline
> The four panels are equal in shape, so a pattern for 1 panel is sufficient, except for making the inner net door
> There would be Ti internal elbows at the apex to allow for use of stiff,
> Vapor permeable fabric would be used for the rear panels if something light and reliable in polyester can be found
> Front panels would be polyester or cuben
> Inner net door would be inverted T zip, and zips would be on both sides of the front pole for complete access
> There would be a small cap fly on top covering zip open vents.
Have constructed a full size frame model to be sure the inside space will be adequate before building a full size jig to make the panel pattern.
Have worked out nearly all the details, but as you know, glitches always come up. If I can't find a good polyester WPB fabric, the rear design will be more complicated, with a net inner and cuben outer.
Would welcome your comments and suggestions.
SamNov 1, 2010 at 2:54 am #1659964
> > Freestanding – not dependent on stakes for support or shape
I know marketing spin makes a big hoorah about this, but does any experienced walker ever pitch any tent without using guy ropes? The stories (and videos too) of 'free-standing' tents becoming air-borne are legion.
> > Minimal vertical and horizontal canopy surfaces – sheds wind, water and snow
Um … if you minimise both the horizontal and vertical surfaces, you end up with a teepee I think?
And why minimise the vertical surfaces: they are what give you interior room.
> > Strong, rigid but flexible frame
Rigid AND flexible?
> > Entry and exit without flooding
Now we are completely in agreement. All those pop-ups with the door over half the floor and your gear … sigh.
The vents at the top of that design will be either a problem in bad weather, or inadequate for stopping condensation. Well, I haven't seen a pop-up which does not have this problem, anyhow.
CheersNov 1, 2010 at 4:53 am #1659970
Mark FowlerBPL Member
Good to see you having a go at this as tent design is one of the big design conundrums – that is turning lots of fabric and poles into a shelter that provides high stability, roominess and low weight – you can only have 2 of the 3. (and I should add ventilation, access, ease of pitching …) A scan of the market will show that tent/tarp design has thrown up many more very different and innovative designs than say packs or sleeping bags. I have wrestled with this for many years and ultimately have decided that you either need to clearly specify the conditions you require a tent for and so accept the design tradeoffs or you seek the greater adaptability of the tarps (HMG for instance).
For a one person shelter a two pole design will be very stable but heavy – poles, even carbon fibre ones are heavy but dome shapes will provide the greatest volume for the surface area (less fabric required). I agree with Roger that self standing is a very low priority unless you have special needs. You have chosen to go with curved poles rather than straight. This leads to better volume higher in the tent (more comfort sitting) but also more area higher in the wind (less stability).
Two different approaches to the orientation of a single hoop pole can be seen in the Macpac Microlite and the Terra Nova Laser tents both with side access. I generally prefer side access to front access as there is less clutter to get past on entry/exit assuming you are reasonably organised (unlike me).
The basic diamond plan of your model will produce a long tent. You need a minimum of around 24" width at foot and head of the inner. If your inner is 7ft long then the distance between pole ends will be around 11ft. This will come close to producing a tent height of 4ft6in to 5ft unless you use a very gentle arc or use differentially bent poles. Many dome tents have a distance between pole ends of 7 to 9ft.
Good luck with your work.Nov 1, 2010 at 6:25 am #1659975
Make your tent with 2nds silnylon (~$5 per yard) and try it out on a few trips before making it with cuben.
Your tent will have a huge condensation problem. Your only hope is to be able to leave the door open when it's not windy.Nov 1, 2010 at 7:02 pm #1660201
Have been using freestanding tents all my life. My favorite was the original Eureka Crescent with only the net part of the door left on and beaks added to create a large covered vestibule. No, seldom use guylines of much length. Used two, front and back, for a while, but realized they were not needed in well chosen spots below timberline that I have to use because have been using a rebuilt WE bug dome with fly (just a canoe tent, really). Part of the idea was to make something less dependent on guylines, which will prop up just about anything, given enough great big HEAVY stakes, and aramid line. Don't think long time MYOG people like us pay much attention to marketing spin.
> Why minimize the vertical surfaces-
To avoid creating wind barriers that need to be held up by big heavy stakes. And yes, it is a teepee of sorts, at least a pyramid type shape that is freestanding:
> Rigid AND flexible? (poles)
Yes, that is the goal. Good initial rigidity, but ability to bend without breaking in sudden gusts, and return to shape. My tests of some multi-directional woven carbon tubes suggest they will do this to some extent. Of the Victory V-Force V-6 shafts you suggested, am looking at the heavier 300, which is 9.9 grains per inch. Heavier, but stiffer and stronger (more layers). Good deals at wribiz.net – comes to about $2.50 per pole section. (Called – haven't used web site)
> Flooding. Glad we agree on that.
> Cap vents at top. Pop-up condensation-
Am not ashamed to borrow from the Walmart type tents if they have a good idea for venting. Just added the idea of making the tent more pyramidal for not only strength, but also greater draft for the vents up top. The closures are for extreme gales, and so the tent will not be inundated during stormy setups before the cap goes on. The apex is also a great place to add some extra cover, as it is the most prone to leakage where all the seams meet. Only plan to have vents at the top of the two rear panels, to reduce zipper and zipper cover length/weight, and to allow the front doors to zip open to within 5" of the apex. The cap will project over the front for stability, and since the pole sleeves leave a gap inside at the top, there will still be some air circulation from the front.
> Pop-up tents and condensation-
Those old "pop" tents were a disaster, but to put every dome into that bag is a bit much.
And most important, many thanks for all the help you have given me in this quest. Should I ever go down under, you will be the first person I "pop" in on.
SamNov 1, 2010 at 7:29 pm #1660208
Dan DurstonBPL Member
I do enjoy a freestanding (ie. MSR Hubba Hubba) or quasi-freestanding (ie. Big Anges FC UL2) tent so I can shake out the crud in the morning and so I'm not totally screwed if one stake pulls out in the night. However, if a tent does require stakes to stand (ie. MSR Carbon Reflex 2) then that's still usually okay unless I'm going to be on snow or sand a lot.
If a shelter requires stakes and guylines to stand then that's a notable con, but a lot of guyline mandatory shelters make up for it by offering nice benefits in exchange such as lighter weight due to less poles. I love my HMG Echo I which requires guylines because it makes up for it with versatility and extreme light weight.
You can't really have a freestanding SUL shelter because the lightest polesets (ie. Fibraplex) are in the range of 200g which is nearly as heavy as some entire shelters (ie. Hexamid).Nov 1, 2010 at 8:07 pm #1660219
Thank you for the thoughtful comments.
Think we agree that the dome shape is the most efficient use of fabric. Am not sure if diamond shaped domes are even moreso than rectangular ones; but every time I did the math, the diamond shapes came out ahead.
Guess freestanding domes are not so popular on this site; but I like them not only for the room and comfort, but also because stakes are not essential to hold them up, just to anchor them with lighter stakes. Maybe it is partly because some of the worst and more frequent disasters I have suffered or witnessed came from popped stakes.
Please note that with the slightly pyramidal shape, the poles are only slightly curved so not to overbend the carbon layup for long periods. Because the poles are stiffer than the alloy ones that come with cross-hooped domes, they don't have to be bent so much to make the frame rigid. Also, the slightly pyramidal shape puts less volume near the top.
Agree 100% about side entry tents. Guess they are called 'side' entry because all the old tents used to be entered from the narrower end, which was the 'front.'
About dimensions: The model was to scale – 2" = 1'.
The floor is 90" wide, 51" deep, 12" deep at the side vents. A 19" x 72" pad just fits, although I use a shorty. The canopy is 9.5' wide, 7' deep and 46" high. Since the side vents are integral to the canopy, the width is less than a TT Moment if you count the Moment's end guys. Built the full-size frame to be sure that these dimensions would be adequate inside. The rear wall is a little too close just when beginning to sit up from a lying position, so expect to add some modestly sized suspended net panels there if the tent is single wall. The width of the head and foot ends increase sharply as you approach the center, but as noted, are only 12" at the vented end walls. I am 5'10" tall, and don't need the whole 90", but know my sleeping bag at head and foor will get wet from the back wall (the front and ends are net), so again, the suspended net panels inside the back walls.
As noted, if a good vapor permeable polyester is not available for the back panels, will redesign for a net inner in the rear half, and use a cuben outer to avoid an increase in weight. Have been experimenting with periodic treatments of polyester Epic Malibu with Atsko, but don't know how that will turn out yet. For some reason, the Malibu seems to work fine for several storms, but then suddenly become moist inside, even during milder storms. It could be because the weather has gotten colder, and if that is so, the Epic is failing when most needed – no good.
Thank you – will take good luck anytime.
Sam FarringtonNov 1, 2010 at 8:38 pm #1660228
Although I like good silnylon for floors, hate the way it sags when the temp changes. For Roger's or Warmlite's silnylon tents that are tensioned front-to-back, you can just tighten the whole canopy when the nylon sags; but this doesn't seem to work very well for domes. Hence, the quest for polyester.
You have given me a good reason to go with a single wall-Epic in the back-construction first time out, so all the glitches are out before the cuben is cut. If a good lightweight vapor permeable polyester were available, it would be a no-brainer. Total insanity would be buying a BD UL tent just to cut the "nanoshield" out of it. Talk about cuben being expensive.
For the condensation problem, thought about also putting a vent in the back wall at the bottom section of the rear pole. Also thought about how more folks are complaining about condensation with the TT Moment than with the taller TT Rainbow. Please note that although the outer canopy will be attached to the floor sidewall in the rear, it will only come down to the sidewall height, about 5", at the side-ends and front. Maybe even taper higher toward the center pole at the front. The beaks on the old Crescent I mentioned to Roger tapered up to about 1.5' at the bottom front point, and I never got wet from 'horizontal' rain in the worst storms. The 2 top vents under the mini-fly will be 1.5-2 square feet in area. This is quite a bit of venting, especially if the back wall is vapor permeable, compared to many other tents of similar design. Guess it is a balance between venting on one hand, and coverage and simplicity on the other.
SamNov 1, 2010 at 8:55 pm #1660233
Did not catch your post until after replying to the other folks.
Enjoy your frequent posts and projects, and was wondering why you sold the cuben fly you put so much work into for the REI inner tent. Seems your post above may suggest an answer.
Folks on this site have converted me from synthetic to down bags, hang lights to head lamps, and maybe there is a tarp tent in my future. A few years ago I spent eons making a double-cross pointy-fronted pole dome design with Epic and silnylon, but gave up on the verge of completion when I realized the weight had pushed over 2.5 lbs and was headed for 3, even with carbon poles that were too fragile and arced to hold up well.
So maybe I will be converted again. But not yet.
SamNov 1, 2010 at 9:28 pm #1660241
drowning in spamMember
Sometimes I'd really love a freestanding tent. It'd be nice when there are lots of people around to trip over guylines. It would've been nice earlier this year when the ground was so hard that I could get a BPL Ti stakes, aluminum y-stake or Easton stake into the ground and ended up cowboy camping while a cougar kept checking me out all night.
Since you're considering using non-stretch polyester fabric, cuben may be suitable for the entire outer…at least if you can somehow acquire breathable cuben fiber.
Have you checked out how Big Sky does their vents? I believe there's one or two other companies that do it the same. Basically they use a fabric wrapped carbon pole to prop open the vents for maximum effectiveness, along with a strip of velcro to hold it in place.
I think I may have missed it… Is your tent going to have a single wall with external poles? That's what I assumed since it would allow it to be set up completely without exposing the interior to rain.Nov 1, 2010 at 9:36 pm #1660247
> or some reason, the Malibu seems to work fine for several storms, but then
> suddenly become moist inside, even during milder storms.
I'll bet that the problem is accumulated dirt. Give the tent a good wash in Atsko Sports Wash and try again.
CheersNov 1, 2010 at 9:46 pm #1660251
Dan DurstonBPL Member
"was wondering why you sold the cuben fly you put so much work into for the REI inner tent. Seems your post above may suggest an answer."
Mainly I'm just a big gear geek, so regardless of how good my current gear is I'm always tempted to sell it so I can try something else. Someone contacted me with a good offer for the cuben fly that would allow me to try other tents, so I accepted. I figured down the road something as specific as this fly could be tough to sell.
The REI Quarterdome T2 was pretty darn good for my wife and I once I had the weight down to about 2.6lbs with the cuben fly & carbon poles. The main downsides were that a little more space would be nice, and the Fibraplex poles are too flexy for high winds or snow loads. I still have the T2 but now that the cuben fly is gone I'll likely sell it.
I'd like to try something lighter (ie. Easton Kilo, HMG Echo II) or a more spacious single wall for the same weight (TT Double Rainbow or SMD Lunar Duo). I'm nervous about single walls though, so of the two the Double Rainbow appeals with it's optional liner. Currently I'm leaning towards the Kilo though if it lives up to its claimed dimensions and weight. Have you thought about a 1 person version of the Kilo? That would be pretty cool.
As it applies to an ideal 3-season solo tent, I think there are some cool possible designs out there that aren't freestanding, but don't require guylines and a lot of time like a tarp. Something like a double wall version of the SMD Lunar Duo would be pretty cool. It's not freestanding but it's quick to setup with no guylines. The main thing I don't like about guylines are the trip hazard, and the long setup time that tends to accompany a shelter that relies on a lot of guylines.Nov 1, 2010 at 10:52 pm #1660260
Single wall all around with external pole sleeves if I can find a vapor permeable polyester under 2 oz/sq yd. That is Epic Malibu, but am not sure it is reliable. It seems to fail unpredictably after working fine through several storms. Roger thinks it is dirt particles, fine dust really.
If re-applications of Atsko silicone solve the problem, I will use the Epic. If not, and since I don't see myself washing my tent on the trail, I will have to redesign the two rear panels of the tent that cover most of the living area, so as to have a netting inner with a fabric outer. Have the design thought out, but no matter how you cut it, single wall is much simpler to build and to use, IMO. But am not ready to go to single non-breathable wall all around without a netting inner protecting the rear living area. Jerry's warning about severe condensation is worth heeding, I think.
So I have had samples of treated Epic and untreated Epic on the back deck in rainstorms all fall, have retreated one sample, and am waiting for the next rain. Roger suggeests to just use a garden hose, but I want the tests to be as realistic as possible. We're getting plenty of rain here this fall – no problem.
Breathable cuben? Is that like a left-handed smoke shifter? After reading Colin's thread tonight about bonding cuben, I'm gettng leerier and leerier, but what else is there out there in that weight range?
Oh, see what you mean. Just apply the Atsko Sportwash product first. Will try it.
Please let us know what tent you settle on. Do read the posts as you do about new tents, but don't have time to do a really exhaustive search for new tents when wrapped up in trying to make one. So if I don't get the current project completed by spring, will rely a lot on you folks to make a choice.
Haven't seen a bear yet this fall,
SamNov 1, 2010 at 11:12 pm #1660263
drowning in spamMember
Hopefully the Epic fabric works out for you since that seems like the most feasible option. Breathable cuben is out there, but so far only Big Sky has been able to use it. Unfortunately almost nothing is known about it. How much does it weigh? Strength? How breathable? How much $$? One Big Sky tent at ADZPCTKO was similar to your design. Would it be worth contacting Big Sky to see if they'd share their cuben tent experiences with you?
I wouldn't worry much about bonding cuben because I haven't heard of a single shelter failure yet. Early Hexamids were sewn and taped, which seems to be the worst combination according to the latest cuben fiber thread, but mine has held up just fine. I've had it in some windy conditions. One time it even pulled a 8" Easton stake out of the ground.Nov 2, 2010 at 12:54 am #1660274
Franco DarioliBPL Member
Take a good look at the Mountain Hardwear Bunker 1 dimensions.
Hint : it is small.(( by design not accident, I believe…)
FrancoNov 2, 2010 at 2:49 am #1660277
EPIC relies on a surface tension effect from the coating to block the passage of liquid water. Get the coating dirty and that surface tension is shot. This makes using EPIC for clothing very unlikely, due to body oils and sweat. Been there, tried that and failed, discussed with the company. They agree with me on this.
So, it may not be 'dirt' or 'dust'. It could be … food vapours, body oils, plant oils or chemicals … most anything which is more hydrophilic than EPIC.
CheersNov 2, 2010 at 6:50 am #1660306
Many tents have these small vents at the top or whatever.
I think that is a total waste for reducing condensation. More marketing hype than anything effective.
I think the vent has to be large, like the door which is 1/4 or 1/8 the surface area of the entire tent.
It should include high up on the tent and low.
With your tent, the door could be left open – your sleeping bag is not directly below it – so that would be a big help.Nov 2, 2010 at 2:36 pm #1660445
Franco DarioliBPL Member
I think that is a total waste for reducing condensation. More marketing hype than anything effective.
No, I disagree.
The idea is to create a chimney effect (stack effect if you like…) That relays on the position (the higher the better) and the difference in temperature between inside and outside.
In this case , size does not matter …
BTW, that is why the Devin's "volcano" stove should be faster than most,,,Nov 2, 2010 at 4:45 pm #1660477
"No, I disagree.
The idea is to create a chimney effect (stack effect if you like…) That relays on the position (the higher the better) and the difference in temperature between inside and outside."
I've made small tents with small vents on the top, and seen reviews of such tents on backpackinglight.com and backpackgeartest.org, and they have condensation.
The volcano stove is a different story, because there's a large temperature difference between inside and outside.
Very little temperature difference between where you are and the outside so chimney affect is much less.
You need large vent area – for example leaving the door open which is a vent that's 1/4 or 1/8 the surface area of the tent.
Just one person's experience – always looking for new information to change my opinion…Nov 2, 2010 at 8:35 pm #1660528
Sorry, thought you were pulling my leg about the breathable cuben. Maybe you are without knowing it, as I am not a big fan of big sky. Fool me once, shame on you; fool me twice …
Guess there is no reason why the mylar in cuben could not be replaced with something else that is microporous. Somehow, I doubt that whatever it is will be available to me to use this winter. Looks more and more like cuben and net, with a different top vent design.
So could you tell me what grade of cuben you are using? I understand the CT1K.08 is 0.51 oz. per sq. yd. If you have had such good results with that, will probably use that with bonded reinforcements at the seams and stress points. Otherwise, am thinking of of the 2K.
I obtained a MH Bunker once, intending, I'm embarrassed to admit, to replace the floor with a deeper silnylon version and the poles with carbon. No, that's not even the dumbest thing I've tried. Anyway, was not very happy with the quality of construction, and immediately sent it back.
Design-wise, it has an elbow at the top of the short pole axis, but none on the long. I have put an elbow on the long also, not just to relax the pole stress, but also to minimize the loosening of the canopy tension above the door when the door is opened. Found that there is still a big increase in headroom over a cone shape, even when the long axis pole is only slightly bent. Found from models that the door can be opened up to 9" from the apex (41" height at that point) without such loosening, but after that there is a bit. Am going to let the door open up to 5" from the Apex anyway, for ease of entry/exit when it's not raining, and d**n (expletive blocked by BPL) the looseness. Can remember to not open the door all the way up in storms-not so hard. Note: have been saying door, singular, but plan to have zips on both sides of the front pole so as to have 2 doors. That's one great thing about MYOG. It's a lot of work, but you can have it the way you want it.
The air is pretty fresh on my back deck where the fabrics are being rain-tested for almost two months now. Not sure where oil could come from. Oh, just realized, maybe from my own fingers when feeling to see if it is dry on the inside after a storm.
But there are always fine particles of whatever in the air here on the national forest border. Anyway, will definitely try the wash before giving up on the Epic. One problem: it's going to stop raining and start snowing pretty soon here, and am not going to wait till spring to get started on the tent.
Agree with Franco about the stack effect. What's not clear, is whether the slight increase in apex height to 46"
will be enough. But don't see how it can hurt to have good venting at the very top, together with lots of venting below. I heated solely with a wood stove for several years, and occasionally had days where the air just seemed so heavy it would not move. Also learned that too large a pipe could lower the draft. There will be zip closures on the inside of the vents, so can play with it and see. As you say, there will be condensation regardless, and that's why the canopy will either be breathable or have a net inner in the back.
Appreciate all of your thoughts very much.
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