I've decided to go ahead and build my own shelter. Here are the pictures of my SketchUp of it.



Height of main peak: 40"
Height of back peak: 23"
Length of ridge line: 112"
Width at widest part: 55"

* The mass under the tarp represents my 6'3" frame


I have a couple of questions for you.
1) I don't have the $$$ for Cuben. Which is going to be a better value: Spinntex or Sillnylon?
2) Where can I get Spinntex and how much is it?
3) What do you think of the design?
4) Where can I find a good how-to article or video on the specifics of tarp sewing, etc?

Thanks a lot.

Edited by FauxRealz on 10/11/2010 22:18:19 MDT.

I believe that the real SpinnShelter has more tie-out points on the sides. I think all the way around I use about ten stakes.

--B.G.--

Paul,

Silnylon 2nds from Quest - $6.30/linear yard (60"x36")
Spinntex from thru-hiker (out of stock) - $17.95/linear yard (60"x36")

Finished weights are silnylon=1.3oz/yd2 vs spinntex=0.97/yd2

So for 10yd2 (just using a nice round number) there would be a difference of 3.3oz and $69.90 for a cost difference of $21.1/oz.

Also, there is a great article by Jerry Adams about making a silnylon tent @ http://www.backpackinglight.com/cgi-bin/backpackinglight/myog_silnylon_floorless_2-person_tent.html but you have to be a member (which I think is well worth the price).

Hope this helps,
Josh

If cuben is out, I would go with silnylon. Spinnaker is noisy (crinkly) and it's pretty fragile. I had some stuff sacks I sewed with spinn and they didn't last long.

How many yards of fabric are you planning to use? Maybe it's worth it to save a bit more money and go with cuben?

Are you doing a zip at the front? Or how are you getting in?

Edited by dandydan on 10/11/2010 23:05:28 MDT.

Paul,

Great SketchUp model! It looks like your rear beak has the opposite overhang as the original GG model. Is this on purpose or a mistake? I've considered making my own and have yet to bite the bullet so I can't offer much advice for sewing. One piece of advice that I do have is to see if you can get a full size print/plot of the drawings so you have a pattern to go off of. A local repographics shop should be able to help you out or a local university's copy shop if they do large format printing. You'll need a little more work on the drawing to export the file to a compatible format but it's actually quite simple.

Thanks for your help guys. I did make some changes to the original.
1) I made it about 14" longer.
2) I added a wall on the back overhang and flipped the angle as well.

I have another question concerning fabric. What is the difference in strength between CF, Spinntex and Silnylon? I'm not looking for anything scientific, just roughly.

And about the tie outs: Is it going to cause problems with six stakes? Or should I go for eight? Or more?

Edited by FauxRealz on 10/12/2010 06:24:46 MDT.

If I had to change my (stock) SpinnShelter, I would make it a foot shorter, but that is just me.

I don't know that it will make problems to use six stakes. It's just that about ten is better. It distributes the stresses better, and wind cannot get under it as much.

--B.G.--

I am just finishing off my own design for a one person tent.
There is always a learning curve when making something for the first time. I will make my canopy from silnylon 2nds so it won't be too expensive if I decide a second iteration is desireable.

Some things that I considered during the design process:
* Can the size/shape of the design be altered to reduce the number of seams?
- I avoided having a ridge seam. My (lack of) sewing skill is my biggest concern.
* How will the patterns be created?
- I will make a full size skeleton frame to use as a template

>Some things that I considered during the design process:
>* How will the patterns be created?
>- I will make a full size skeleton frame to use as a template

So what was your answer to how will the patterns be created? That's the part that stumps me. I tried the Sketchup, but then what do you do with the picture? Is there an 'export to patterns' button? I found the learning curve of the software and my impatience to get started didn't mix well.

You could also sew the first one from any old fabric. Perhaps use an old sheet. You don't have to complete it, just use it to test your pattern.

For creating a pattern, it helps if you have a familiarity with CAD software. Luckily for me I'm using it everyday for work. From SketchUp I would export to a .dwg and import that layout in AutoCAD and plot it to a large format printer or pdf. Unfortunately you'll still have to piece some things together as most plotters go to 42" wide rather than the typical 60" wide fabric.

I'd be willing to help out when possible and send people a pdf of their model so it could printed locally.

I once saw a billboard manufacturer use an old slide projector to do this. He projected the image onto an enormous piece of plastic. He then went up on a ladder and traced the image onto the plastic (actually punched tiny holes in a line).

With a computer projector (easily rented or borrowed), one could "blow up" a design onto something like Tyvek, moving the projector further or closer until the desired size is achieved. Then you could just trace the lines and cut them out.

Nice drawings!

You can also mock up your design with 1-2mil drop cloth plastic. It's around $4 for 10 x 20ft. I've been using silnylon seconds from Noah Lamport at $3/yd. They'll charge a cutting fee for less than 10yds and will also charge a fee if you want it boxed up instead of on a roll. Shipping on a rolled 15yd remnant they had was $17 for me.

Is there a door? Zippered?

I don't think you can sew Cuben, you use some sort of tape.

You will have condensation problems with a small volume tent like that, in my experience. If you can have a several inch gap all the way around, and if you can leave the door open when in high condensation conditions it would help.

On the stock product, there is an opening, but there is no zipper or closure. When I modified mine, I added bug net behind that opening near the front pole.

Yes, I think it is good to add a gap all the way around the bottom. I sewed a bug net skirt of about 3-4 inches all the way around mine. For a storm, I can lower it down. For a warm night, I can raise it up for ventilation.

--B.G.--

Those that have access to suitable CAD software and a plotter have it easy.

For the rest of us there is a simple but more time consuming method.
First draw a plan (top down view) and elevation (side view) to scale. You can use something really simple like Powerpoint with the grid turned on. Then use basic Pythagoras (right angled triangle, hyponteuse squared = a^2 + b^2) to work out the length of each side and some diagonals.
Use these calculated lengths to make a full size model, see picture on Rogers website here.
Finally, drape pieces of a non-stretch material like polythene or paper sheet over the model and cut to fit.
Now you have your patterns!

Cuben can be sewn, but taping leaves no holes.

Spinn cloth does get flimsy with stuff sacks, but not so with shelters. (See Dan D."s comment above). GG SpinnTwin has remained sturdy along with another homemade tarp, using a pattern found at a BPL article.

Nylon works fine, too, but it does stretch. Bungy-type tie-adjusters are useful in keeping the pitch taut.

Spinn cloth has become scarce among the usual suppliers.

Edited by rambler on 10/13/2010 11:25:33 MDT.

Is Spinn cloth scarce to DIYers because they want people to buy finished products?

I doubt it's some insidious marketing scheme. Many of the cottage sites also make money buy selling their fabrics retail. When you make a retail product in small volumes, the cost of labor becomes really high per item made. Selling in large quantities lowers that per item cost and subsequently increases profit. As such, for companies dealing with limited production runs, it makes more sense to sell the materials at retail. This eliminates the labor costs of production and they still get a profit for simply being middle men.

There are two likely reasons for the shortage of spinnaker

1) Manufacturers have run into a production/supply problem and there simply isn't much spinnaker to go around
Or more likely...

2) Cuben fiber has made spinnaker all but obsolete. When you look at the fabrics from a weight/cost, cuben isn't that bad. Especially when you consider that it's essentially the top of the line and should command a price premium due to lack of competition. Spinnaker is roughly 30% heavier than .74 cuben, but only 45% cheaper (based off questoutfitters.com prices). The weight vs dollar savings get even better when you compare spinnaker to the lighter and cheaper versions of cuben.

>>"What is the difference in strength between CF, Spinntex and Silnylon? I'm not looking for anything scientific, just roughly."

I think spinnaker is junk and would never waste my time or money building anything out of it. Its expensive, noisy, tears easy and is barely water resistant.

If your going to use Cuben I suggest using the CT2K.08 stuff. Besides the price it makes a great shelter material. The plus is you don't have to sew it which is handy for the non-sewing type. Its a great material but comes at a super inflated price.

If cuben is out of your budget I would suggest using silnylon. You can't be its strength to weight ratio then when you factor in the low cost with its overall great performance its probably the best material going for tarps and tent fly's. The only thing is it does stretch some. The better the quality material you use the less it stretches. So make sure if you choose Silnylon that its Nylon 6,6 and not that Asian made crap.

Cheers,
Lawson

Edited by Mountainfitter on 10/14/2010 17:56:02 MDT.

"I think spinnaker is junk and would never waste my time or money building anything out of it. Its noisy, tears easy and is barely water resistant."

That's interesting. Maybe you got a hold of a bad lot of it.

I'm happy with the spinnaker fabric that I have. My GG SpinShelter is my favorite, and I purchased more spinnaker fabric to sew my own waterproof stuff out of it.

"Its noisy" If you don't have it taut, it can rattle. Solution, stretch it out better.

"tears easily" Maybe with yours. None of my spinnaker has any tears at all. If you didn't have it taut, then it can rattle so badly that it weakens and tears, I guess.

"barely water resistant" Maybe with yours. Mine seems to be nearly perfectly waterproof. It is so slick that rainwater drops just shoot right off.

Look around. Maybe there are better types of spinnaker fabric. There is a slight difference in appearance from one to another. At a distance, they all look alike.

--B.G.--