Long time lurker and camping enthusiast, first time poster here.

My significant other is finally getting interested in doing some backpacking and bike camping with me. I've only used tarps in the past (or shared my friend's 2-man) and my car camping tent is too big and heavy (15lbs!) to carry along so I'm looking to make something of my own to save on costs.

Without further adieu, here are my plans:

Basic Material List
30D silnylon outer layer
70D silnylon (I'll find a way to counter the extremely slipperly surface) bathtub bottom.
No-see-um mesh skirt attached to the outer later that I can connect to the bathtub to keep the bugs out (probably with just a couple spots of velcro). Also have a mesh door.
Waterproof zipper on the fly and regular zipper on the mesh door
1" nylon straps for guy lines along the base reinforced out of 70D SilNylon.
1" nylon straps for guy lines where tent poles would be supporting the tent (3 points) for flexibility of not needing poles.
1/4" Shock cords at the same location as all nylon straps for windy days (so the tent flexes a little instead of flapping.
5/8" aluminum poles for supports
Gutermann 100% polyester

- Goals -
3-4lb tent for backpacking and bike touring.
Flexibility of having a separated floor that I can re-purpose similarly to a 5 x 7.5 tarp if desired during the day or if a 2nd shelter is needed.
PLENTY of room for 2 people and gear (50x90 for 57" roll...wider if I can get +60")
Ideally hold up very well against 40-50mph gusts












For my Questions and where I'm looking for help...I've found a few guides (most notably this: http://oakhillwanderer.com/tarp-tent-full-tutorial-and-set-up/), but I'm wondering if there is anything I should look out for with this design?

- Any concerns with the general design of the tent? I've also created a design that is similar to an A-frame but this design seems to provide a lot more headroom for two and with hardly any extra material (24" of pole and barely any extra silnylon).
- Is 30D SilNylon strong enough for a single walled tent (I've only owned 70D flys so I'm quite concerned that 30D is too thin)?
- Is 70D SilNylon strong enough for a base (I have a plan for the slippery surface)?
- Is 30D SilNylon going to be significantly see-through or end up trapping lots of heat due to sun getting in?
- Should I go with a double walled tent (base+mesh for main and a rain fly)?
- Is there a recommended stitch that I haven't found? It seems pretty simple to do what that guide shows (french stitch?) and I figure 12/in is probably about right.
- I'm about to buy a 750yd spool of Gutermann but will that be enough?

Edited by jordo_99 on 07/11/2012 10:57:57 MDT.

I have posted this before and is meant not to discourage folk but as a general reality check.
By the time you take into account exactly how much you spend getting all the bits (including postage) and you have made your second or third version , most probably you will not save money however you will have the satisfaction of having your own custom made shelter.
A way to cut down on possible mistakes is to make a full size version using cheap materials (like a painters drop sheet) and that will give you a much better idea of size , how the panels should be cut and possible performance if you have a lawn to set it up .
Just a quick tip on the design. The triangular roof panel will collect water when it rains .Draw a circle just a few inches behind the door apex and that is where it will be.
Franco

Thanks for the input.

I ended up modifying the design for a 48" front (same everything else) so i'm thinking that should help out the water run off.



As for the comment on cost and what not:
I'm doing it for the experience mostly but I also have a passion for this kind of thing. I'm very much a tinkerer and I'm also planning on making some custom gear for touring and bike camping...which is ultimately what this tent will be used for. I really REALLY want to cycle across the USA next summer (either West > East or Canada to Mexico - not sure which yet) and I want to make all the gear for it. (bike bags, tent, backpack, etc)

Here are some pictures for the new design. I've also added a nylon strap to the middle to try and avoid water from pooling. All other straps are added as well.





Question: I like the 48" in the front (and extra width I added after realizing the guys were pretty cramped when I set them inside) better anyway but do you think it will even help solve the problem of pooling? If not, I'm very open to a tunnel tent. I started with this design because I thought it would be easier to make, I liked the flexibility of pitching (poles or guy lines) and having straight poles instead of curved ones. Again, I'm no expert and haven't designed my own tents before so I'm not sure what is possible with some of the materials I'll be working with.

Edited by jordo_99 on 07/12/2012 00:51:49 MDT.

The entry poles are not triangulated and so need tie downs for stability? If you use the points on the fly to the left and right, the force will tend to pull the stakes up and out of the ground. Stakes work better the more the are resisting shear i.e. further away from the tent.

If you have stakes wide of the tent, you no longer need the cross pole since it will be under tension anyway. This is true even with close in stakes, but not as stiff.

You still have a problem with pooling water. You need a steeper drop to the foot area?

I like the design. It is similar to something I've been thinking of making. I'm still absorbing the design considerations and possibilities so your efforts are helpful. I look forward to your progress!
Nate

Thanks for the input.

I'm going to start from scratch on a new design...I'm thinking that side entry would be better and that would greatly help with the potential problems that are coming up. Probably something similar to the Lunar Duo but without the curved top and a wider profile.

Along the same lines...I'm considering using a single pole inside the tent and well thought out guy lines (possibly a 2nd, smaller pole outside the tent on the other side) to cut down on the weight of a 2nd pole and more material...something close to a 4 foot pole on one side and a short one on the other, but outside the frame.

This article on this site plus parts 2 and 3 give very good arguments for tunnel tents
http://www.backpackinglight.com/cgi-bin/backpackinglight/tunnel_tents_part1.html?id=a7ka27pz:69.20.70.86

and features home made examples

geometry simpler for home construction amongst the other reasons for a tunnel design

I would suggest reviewing this: http://www.bushwalking.org.au/FAQ/DIY_RNCTents.htm
This is Roger C.'s web site for his tents. I consider 3 pounds to be a maximum for backpacking for the two of us, 2 would be better. Note that you can also get the plans for two person tarp-tents here: http://www.tarptent.com/projects/tarpdesign.html

A nice looking design, but as Franco pointed out, a more continuous curve is probably needed to prevent puddling. Really, a flat top is not good for shedding rain, but, it could work with proper tension, since it could flow towards the back. Personnaly, I like to simply crawl in, so the back and front are the same size, though.

So I had some time yesterday to test my patience with some drop cloth and gorilla tape and made a prototype of my new design.

The size is just about perfect for what I want. Only thing I would want to change is to have catenary curves as it was hard to come up with a taut tent (probably a lot due to the material though. I think catenary curves would end up making this a much more complicated project than I want to deal with right now so I'm going to hold off unless someone tries to convince me otherwise.

I'm also tempted to make the vestibules larger (or at least one larger) to fit my bicycles. However, I'm already planning on making a silnylon cover for my bike to replace the 7-pounder I'm currently lugging around with me.

This design was inspired heavily by the SMD Lunar Duo. I plan on trying out some adjustable nylon straps for staking in just like the Duo uses but this will have some different dimensions (and not a curved top). The inside mesh and bathtub will be done with my own design as I'm not so sure I like the idea of using shock cord to support the bathtub.








I really like the curved zipper/door in the mesh but I'm thinking that a triangle will be more feasible.

As always, comments and questions are encouraged. I think I'll give it a week before I order materials and dive in.

Edited by jordo_99 on 07/15/2012 14:01:24 MDT.

Try moving the pole line over your head or at least shoulders. This will keep the fly from being inches from your nose and not detract from the space. The pitch is steeper over your head and shallower over your feet.

I really like the zip on both sides along with dual vestibuli. We just might be sharing patterns!

The idea is something a little borrowed from this:
http://www.tarptent.com/sublite.html

One thing I didn't post before was that I had added vents to the reinforced pole area:



Not a bad idea to move it down a bit, but the fly is still at least 18" above my face. I realize that the attached images didn't really show that well...but it's 24" high at the ends of the bath tub...here's a better view:



and the same view but with the ridgeline shifted:



One more of the new "shifted mod".




I'm still a bit unsure which I like more. I guess with it shifted like this I can drop the height down a few inches and it shouldn't be noticed as much. Only downside I see is losing a very small amount of square footage in the vestibules...which shouldn't be a problem

As of now I'm planning to put off building a complete tent like this and use a tarp tent for the time being basically the same thing as this but with a tarp and detachable mesh/bathtub).

I'm a fan of that approach for a two person shelter. This should help:
http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=56641&skip_to_post=482874#482874

I didn't bother with the offset ridge line, and haven't had any issues. Also made an inner net tent shortly afterwards. Here are a couple more photos.

What are the dimensions of the bathtub in it? Mine's supposed to be around 54x90x3 (4.5 x 8.5 feet, 3 inches high).

Looks like it's a little smaller than what I'm planning so I'm interested to see what you think of the size and design...anything you'd change about it if you could?

I hadn't found your tarp yet but it's getting me excited for this again (was planning to put it off until Spring...might bite the bullet and order soon now).

Jordan,

I've been making 1 and 2 person tents similar to yours for about 40 years now. Here are my arguments for leaving your ridge line at the mid point of your tent.

(1) It makes designing and patterning easier because one half is simply the mirror image of the other half.

(2) I like having the high point of the tent in the center. It is where I position myself while changing clothes, for example, and things at either end of the tent are equal distance from me and easy to reach.

(3) Moving the ridgeline towards the head reduces the angle of the longer tail end. The flatter long end is then more vulnerable to water pooling and snow build up.

(4) The longer end of the tent also makes it harder to keep things tight and reduce flapping because it creates a larger piece of unsupported fabric. I notice that several of the tents that have this design (e.g. SMD Haven, Peak 1 Cobra, etc.) have added an additional tie out to compensate for this.

(5) Having one longer end makes it more difficult to reach things that have worked their way down there.

(6) With a symmetrical tent (mid point center line) one doesn't have to figure out which way to have your head prior to setting up the tent. Just set it up and figure it out once inside.

Everyone has their preferences. These are mine. No right or wrong here.

Here's a photo of a 4 lb, side entry, 2 person, 2 vestibule, 2 door tent I made about 35 years ago. It is symmnetrical end to end and side to side. Still in good shape except for the internal door zippers. It has an arched cross pole and the two vertical poles can be rotated and adjusted to tighten the tent from the inside without leaving the tent.

Jordan,



Daryl

Edited by lyrad1 on 07/21/2012 10:32:16 MDT.

The floor of the inner tent is 90x46. The walls are 5 inches tall, which is a really nice feature in heavy rain. Since I am 6'1" with wide shoulders, I figured it would be a tight fit with my wife, but honestly since the side walls are completely vertical it isn't cramped and we can both sit up at the same time as well. The intent certainly wasn't for a very spacious tent, but it works well for us. 1.9 lbs for a double wall tent (minus stakes and trekking poles), using only 30d silnylon, and .7oz no see um mesh.

...I've got all my materials here now. I'm now ready to get serious with my tent after finishing my "warm-up" projects:
http://cache.backpackinglight.com/backpackinglight/user_uploads/1344266469_66463.jpg
hammock setup (gathered-end hammock 1.1oz ripstop, bug net and 8x10 flat tarp 1.4oz sil)

Now, I'm ready to make the jump to this tent again but I have just a quick question for you guys:

Where do you think I should put the cat curves? If you look at the attached picture, I'm already set on the ridge-line highlighted in Green, but undecided about the rest...two seams, one of them I highlighted in pink, will have zippers and it doesn't seem like a great idea to put curves there to me...but I'm no expert.


If I do all the seams/hems except the zippered ones it comes to 16 cuts I have to make, but with only 3 different curves (silver lining I guess) so it would add a good chunk of time to the project.


Edit: pic doesn't show dimensions very well...here they are for anyone interested:

Bathtub - 90" by 54" and 4" tall
Width - 112" at the bottom (door stake to door stake) and 56" at the top (pole tip to pole tip).
Height - 48"
Length - 114"
Vestibules - 22" (for 11sq/ft each)

Edited by jordo_99 on 09/05/2012 17:13:40 MDT.

I'd put them everywhere - I think you'll get a noticeably tighter pitch. I would do the zipper seam as well, I don't think you'll have any problems there. The curve is so slight that it won't cause any issues with the zipper.

Thought I should finally get around to updating you fine people on this project.

It's been done for a while now but I got lazy/busy and with the seasons finally changing here in the midwest I'm getting the bug again and set up my tent to take some pictures (and seam seal it as soon as the weather permits).

Dimensions:

49" tall
54" by 96", 4" tall bathtub floor (36sqft)
28" by 57" per vestibule (22 square feet)

Weights:

Fly (30D Silnylon): 20.4oz including guy lines
Netting/Floor (30D Silnylon and NoSeeUm mesh): 18.75oz
(2) Carbon Fiber poles - 3.75oz
(6) Stakes - 1.95oz
6.5" by 18" Cuben Fiber Stuff Sack - .25oz

Total Weight: 45.10oz


Materials:
$72 -- 12yd Silnylon (8.3 for fly, 3 for bathtub floor)
$10 -- 3yd NoSeeUm (inner net)
$0 -- leftover 200D oxford for reinforcements
$8 -- 12ft of #3 zipper for inside, 8ft of #5 zipper for outside, 6 double tabbed sliders
$10 -- rest of the notions (plastics, tieouts and guy line)
$40 -- (2)51" Carbon Fiber Poles from Quest Outfitters--assembly needed

Cost: $140

Pictures:












I'd be happy to take some detailed pictures of certain parts of the tent upon request...I plan to take some of the tie outs points and the 6x17 cuben stuff sack which holds the poles, tent and stakes each in their own sections and has a handle.


Overall, very happy with how this turned out. With some more fiddling I can get a better looking pitch but the doors will always have a small amount of wrinkles in them. However, I think that if I had used a centenary curve on the zippered seam I wouldn't have a problem with this. Regardless, it functions the same.

I however, have two things I still want to change about the tent...the netting is slightly too big so it droops a little and I want to add a strip of sil to cover the outer zippers. Will only take 30 minutes to alter those and then I'll have no complaints left.

Once I seam seal it and get a few nights in it to test condensation issues I'll know whether or not I need to add some vents...thinking I'll need to so I'm already looking into that.

Edited by jordo_99 on 04/18/2013 14:51:51 MDT.

JP
"Wrinkles"
I am familiar with those, my mirror has them too.

Try guying out the door panels further out, about 5" to 10" further out.
The tip will be further away from the ground.

Thanks! I'd forgotten that I designed the tent to have the other 4 points sit a few inches off the ground (they're currently only around 1" instead of 3".

I'll try to move things around once the ground isn't as soft/muddy and post back results in a few days.