trailstar(copy): a lazy man’s pitch

[Ivo Vanmontfort]

I have already made ​​several shelters in trailstar style. Because I'm a lazy type I want the shelter easily transform into a full closed type in bad weather. Now, I must not lie on my stomach to close the shelter. On the inside, in the top I made a loop that I connected to a line.
However, I think it is better to place the loop Slightly halfway to keep the canopy tight. In this
dutch report on my blog you will find (skipp 45 seconds) a You Tube video to illustrate everything.

[Jerry Adams]

Maybe a zipper is better. At least that's what I've found. Yeah, it can fail, but in that case I can just do what you did until I fix it.

[Nathan Meyerson]

I have never had my hands on a trailstar, so my guesswork is based solely on pics and reviews, but I haven't found a solid confirmation one way or the other.

It is apparent in pics that the bottom edges are cut with a catenary curve. Are the ridges connecting each of the panels also cut with a cat curve?

My assumption is that each of the 5 panels is an equilateral triangle, with the base of the triangle cut with a catenary curve, but the ridges are not cat cut.

The ridge an are reported at around 78 inches, and the bottom(cat cut) edge is measured at 84 inches(increased length is accounted in the deflection from the cat cut) stretched flat. Based on my math this requires a 68in wide piece of fabric.

Can anyone with a trailstar confirm that the ridges are cat cut or not?

I want to make a similar tarp and am playing around with sizes/fabrics.

[Greg Mihalik]

Ivo,
Consider this –

The blue line needs a smooth ring attached (girth hitched) at the bottom and another somewhere above. Or knots, as you have done.

A line (red) is fed through the rings and tied off into a loop, or the ends can be left free to attach to the fly.

With the fly attached to the red line, pull the line up or down through the loops on the blue to both raise and lower the fly.

[Mole J]

From looking at mine, I'd say the edges of each triangular panel are cat cut (it wouldn't pitch tautly otherwise).

Is it not made of just 5 equilateral triangles, each with the same cat cut edges? I thought it was as simple as that.

I guess Ivo (or Ron even!?) could answer that better for you.

[Ivo Vanmontfort]

Without zipper makes this versatile shelter unique
With makes him "ordinary".

Greg,
Thanks for the effort of drawing.
It is an idea but for a large gap, the highest ring at the blue line must come in the top.
I have been trying to fasten it at the walking pole but then you pull the pole out of the top.
It must be fastened to the fly

Nathan,
my shelter has a maximum of 5 cm deflex on three sides.
I think it's less in an original.
MLD has, I think extra wide silnylon.
I have extended the silnylon with an extra triangle. Watch video and pictures

[Greg Mihalik]

"It is an idea but for a large gap, the highest ring at the blue line must come in the top."

Ahhh… because it "folds" the fly rather than "gather".
Darn. It's the "morning crawl" under a wet fly that I want to eliminate.

[Jerry Adams]

"Without zipper makes this versatile shelter unique
With makes him "ordinary"."

I'm not saying no-zipper is totally bad – saves 1 ounce, eliminates a possible failure point.

No one makes a mid for one person that has a rectangular area for sleeper on one side of pole, triangular beak area on other side of pole for entry and storage. Trailstar does this nicely.

With a zipper, you can get better ventilation and visibility when the weather is fairly good. Easier to get in.

[Greg Mihalik]

Once I'm home I forget how much I hate crawling under a wet fly in the morning to get it open. This thread is timely.

I'm going to try a LONG zipper pull next time out. As in long enough to extend from the closed zipper to withing easy reach while sitting well back. The cord might be a bit of a nuisance, but I think it's worth a try.

[Nathan Meyerson]

"Is it not made of just 5 equilateral triangles, each with the same cat cut edges? I thought it was as simple as that."

The triangles cannot be equilateral, as they would all have the same sized edges, or nearly the same if they were cut with a different catenary curve.

In an email, Ron confirmed that only the ridges are cat cut, not the bases, so each triangle has a base of 84 inches, and the two sides are 78 after the catenary is accounted for(would increase the length by a few inches).

Hmmm.. Yes it appears he is using wide silnylon.

[Jerry Adams]

It's never made any sense to me to have cat curves on the base. Seems like more of a fashion thing than functional.

[Kevin Beeden]

A catenary cut on the hem of a tent allows the panel to be pulled taut, spreading the guying tension across the panel. So, unless the hem is so low as to be loosely hanging on the ground, I'd always look for a cat cut on the hem of tent panels.

[Matthew Pullan]

I have a friend who allowed me to measure his Trailstar, although I later found the exact dimensions on Ron's website. Once you know the baseline they are a doddle to draw up in Google Sketch Up. I thought all the seams on the Trailstar had catenary, although, out of respect for Ron I will not make my measurements public here. Basically just add a few inches catenary here and there and Bobs your uncle. If it is for just one camper you could downsize it a bit, as I hope to do (eventually). I agree with Kevin, that catenary on the hems gives a tighter pitch. Anyone can see the pitch is far more aesthetically appealing with cat cut on the hem. The wide silnylon may be more of a problem, as will working a reinforcing patch (neatly) into the peak.
Matt

[Jerry Adams]

Okay, maybe cat on hem is more than fashion : )

Cat on ridges is much more functional

I've tried cat on hems but it didn't seem like it made much difference. I had one side with cat hem and the others straight and it made so little difference I quit doing it.

[Matthew Pullan]

Well, when I made my last tarp I didn't bother with cat on the hems simply because I couldn't be bothered making more jigs. In all fairness, you are right Gerry, it's not a matter of life or death. Some have said the edges flap less in the wind with cat cut, that I couldn't tell you. When I said aesthetics, I meant the look of the tent as a whole, rather than the look of the panels. Looking at both the trailstar and some of the projects posted on this site, I would still say cat cut makes for a more pleasing end product. I suppose that is fashion. That being said, it is not the first time I have heard about cat cut spreading the load etc. In fact, it has been said that catenary is only a rough approximation of how the fabric actually deforms under it's own weight, but it helps.
Matt

[Jerry Adams]

Cat on ridges really helps

I made something similar to trailstar, except a zipper up one ridge. I had cats on two of the ridges. The ridge with the zipper was not cat and very difficult to get taught. There were folds of fabric that went parallel to ridge. It flapped in wind. I re-did it with cat cut and it is much better.

I don't think the exact shape is that important, but it needs to be even. I've free-handed it and it didn't work so good – some places were tight and other places were loose. Use one of those spreadsheets to calculate points and measure carefully to get it even.

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