When Things Go Wrong

Thanks for the thorough reply Roger. Like half of us on this site, we would just LOVE for a production model of your version 10 or version 11 or whatever version you are up to . Like the other half of us, I would also love to get a pattern for MYOG to play around with, eg, cuben. Maybe you and BPL could come to some arrangement!

That aside, I am thinking about making poles like yours to replace my Nallo poles. How are the pole angles joined together, and what is the angle? How do you insert them (fully assembled before sliding into the sleeve)?

Thanks again for the thoughtful reply :) I really appreciate the lengthy ones!

I agree RE: cuben limitations. I wonder if there is a cheaper 'rigid' fabric I could do a mock-up with?

>Could you do this to a Nallo? I don't think it would work as the end bells will be the wrong shape. There would be lots of slack and creases.

What do you mean by "end bell"? Do you mean the joiners wouldn't work well in the Nallo sleeve (too narrow, too wide, wrong shape…)?

>So the bends are done via the joiners

On your website, you state "At present I make my own bends out of stainless steel tubing". Has the availability of pre-made bends changed (eg Fibraplex custom)? Or is this still the biggest limitation to making a Caffin tent?

>Sleeving the poles makes the tent a lot more storm-proof

Agreed again. This is one of the advantages of yours and the Nallo design IMHO, but the flex needed to use a continuous CF pole on the Nallo is too great, as I'm sure you know. Sleeved poles on the fly also allow you (in theory) to use the fly and inner separately, or to pitch and remove the inner with the fly still protecting you and the inner tent from rain. I used this feature a lot on the older MacPac tunnel tents, but it seems they no longer have this option :(

Thanks again for your knowledgeable replys.

TYVEK!! Great idea Roger. Cheers :)

Heavens no, no one (I think) is saying that those tents are inferior to tunnel tents. Quite the opposite in some ways. It's more a question of efficiency in terms of weight. The Soulo is a one person tent, and the 2-person Staika is almost twice as heavy as Roger's tent or the Nallo2.

> TYVEK!! Great idea Roger. Cheers :)

Welcome. :-)

Added advantage is you can use tape or glue and peel it apart for adjustments until you get a suitable shape.

I'm thinking of having a go at a tyvek tent with some complex curves in, and without a suitable computer program to work out the shapes, this seems to be the way to go. Now if I could just find a suitable glue which won't clog the needle come stitching time, I'd have built in seam seals too!

Hi Roger T

> Now if I could just find a suitable glue which won't clog the needle come stitching time, I'd have built in seam seals too!
When you do, let me know! I have not found anything yet, and a gummed-up needle is a right pain!
You could try using an oiler – that would probably work.

Cheers

> a device for oiling the thread/needle on the sewing machine?
Yes. You can get them for commercial high-speed machines where the needle can otherwise get a bit hot … and melt the thread.

> cf poles: do you put some sort of strengthening ferrule on the ends to prevent damage from the angled ss jointing pieces?
The tubing I use is not pultruded kite stuff which splits easily (eg Avia). It is 5-layer bidirectional wound CF tube meant for high-impact arrow shafts. That means there are 2 complete layers of winding around the tube, and that is pretty strong. In addition, the CF thread is less stretchy than an Al ferrule so a ferrule would not add much to the circumferential strength.

However, the very end of the CF tube is susceptible to localised stress and impact damage under extreme conditions. I have known a pole break at the end when the user did not fully insert the SS joiner.
.

.
Let me hasten to add that I have a handful of aluminium tent poles which show exactly the same damage – I got them from a gear shop as scrap. You can break anything if you try!

So it can make sense to add a very high tensile aluminium ferrule around the end of the CF tube in some cases, to prevent incidental damage. I have done this for my winter tent using 8-10 mm lengths of snug-fitting Easton arrow shaft 7075 T9 tubing and high-strength epoxy. (Yeah, lucky to get such a good match in sizes.)
On my summer tent I do not use external ferrules as they don't get such harsh weather..

Cheers

Hi Rog T

> I'm looking for some alloy tube of the right diameter to slip inside as my joint piece goes over the outside.

Exact internal diameter? I may be able to offer suggestions.

Cheers

Hi Rog T

Nice looking tent, especially for £30. Lots of guy rope attachments too. Weight – yeah.

> Some of Rogers arrow shafts and joiners might get the pole weight down a bit from the rather hefty 1lb 2oz solid fibreglass set which came as standard.

Um – I would need to know what the radius of curvature is for the front and rear poles. It is possible to do some quite alarming things with Easton poles by giving them a 'prebend', but you can NOT do that to CF tubing. It is straight! In this case I suspect that the radius of curvature would be too small for straight CF by itself, but Easton poles might take enough prebend.

Short segments of CF with several bend-joiners? Maybe. Not sure how it would look, but not impossible.

Btw: Fantastic video! Thanks.

Cheers
Roger

Roger T, I'm surprised any of the old Peapods are still around! Versions were made with aluminum poles so you should be able to get Eastons or equivalent poles and ditch the fiber-glass. It was a great tent in its day and the weight is pretty reasonable.

I remember one problem with the Peapods was that the long unsupported sides deformed in strong winds and heavy snow. Adding long guylines to the apex of the poles and pegging them out in line with the tent helped reduce this problem by pulling the poles against each other.

The VE25 is twice the weight of my Peapod, with slightly more innertent floor area, though more useable height for sitting in.

Geodesics start to make more sense weightwise for bigger tents designed for more people. Their hexagonal shape sheds the wind equally from any direction, and with plenty of snow built up around the skirt on the fly, they are rock solid. So for everest expeditions, they have the edge on the ledge.

For wet moorlands and mountains though, poor peg grip and an unyeiding skeleton on a tall design with steep lower sides can combine to work against stability in high winds.

In these circumstances, a tunnel pitched tail to the wind is a better proposition weight for weight. The very light geodesics and semi geodesics such as the TNF Tadpole are vulnerable to storm force winds in my opinion, because the extra pole lenth can get distorted into shapes that snap them.

Hi Robert

On a more technical note, we distinguish (rather roughly) between 'domes' and 'geodesics' by counting the number of poles. A dome may have 2 -3 poles, while a geodesic often has 5 – 7 poles – and these are often made from larger diameter tubes as well. You can imagine the increased strength coming from all the extra poles! And, of course, the increased weight.

The other half of the story is as others have indicated: porters to carry the loads and having space for larger numbers of people.

But we are Ulers!

Cheers