Gear

Mike - if you mean the burner that comes with the mini trangia set?  I thought that was just a standard Trangia burner - it's the pot and stand which are the 'mini' part...

I think that that sort of burner has too  wide a flame pattern for the width pots you are talking about.  It would send flames up the side of the pot a lot, and overheat the cone metal.  You want a more focussed flame patttern.  e..g a chimney stove or a Starlyte or an open burner made from a red Bull can.

You could make a 'flissure' version of the cone - which splits apart and would nest inside your pot.

 e.g.

G wumpy wrote (see)

My first efforts at a Clone for a Snow peak 450 cup. Many thanks to CP for the program and Yonky for the material

I've finally been prompted to address an issue that has been niggling me for some time; the potential for the Flissure joint to 'cheesewire' through itself, or for the V-slots to split.

The solution I thought of was to put little terminating circles at the end of the slot.  I held off doing this because I wasn't sure if this would cause the joint to become sloppy (as there would be no well-defined alignment position).

However, UltraMagnus posted his clone on this thread on BPL, with little circles just as I'd envisaged, so I've added them to the script.  You can choose to use them or not.  I haven't built a clone featuring them yet.

The BPL thread then went off into a heated discussion of the legality and morality of making your own clones, which, as the originator of the script, made me ponder.  It seems that US patent law is different to UK law (and, I suspect, the rest of the world), in that it seems US law says making your own thing for personal use only is a patent violation.  UK law says personal use is not a violation.

I'd like to thank b_a for digging out Trail Designs' view on personal clones, where they say their objection is to commercial exploitation.  So, whatever the US law is, TD choose to follow a UK model, either because they're nice guys (which all accounts suggest they are), or because it would be stupidly expensive and largely pointless to pursue.

I've added my rationale to the end of the BPL thread, but I'll just echo that the main reason for choosing to use 'Caldera Clone' was to make sure that it was obvious where the idea came from, and that, whilst the script is my implementation, the concept of the Caldera Cone comes from Trail Designs.

The other thing that came out of the thread is that TD do make a Fissure Cone, which is one of the reasons that many script requesters mention as cause for them asking for the script.  Since TD don't publicise the Fissure Cone, anyone looking at their website wouldn't know that they make it, so are forced to resorting to make their own cone to fit the pan it supports; there doesn't seem to be one to buy.

So, if you like the idea of a two-part cone to fit in your pot, please get in touch with Trail Designs, and ask them nicely if they'll make a Caldera Fissure Cone for you.

hey I'm trying to spec a Cone system, currently in my mind's eye.

So if i get a wide enough, shallow enough, pan then the cone is short enough rolled up it fits inside the pan? Is there some critical width/heigh ratio I should seek from the pan?

 Also don't you need the cone to be sufficiently wider at the base than the top to make the system stable? So not a steep-sided cone?

 Currently the only pots I own are the Duossal pans from a Trangia 27 kit, it was stated by CP that the Duossal have too small a lip, not rolled like the HA / Alu type pans, so can't be used? Not unless there's some pegs or something under the pan to take the weight???

I ordered a Jetboil and next working on my Cone system, intention to own both as they are complementary I think.

Have a look at pages 9 and 11 of the readme.doc or use the 'print thread' option at the bottom of this page to see the last 500 posts, and scroll through to see lots of pictures.

On the template, the tabs are identified by the 'V' cutouts at each end of the tab.  The fold line is shown as a dotted line.

The slots are shown as a simple, four-sided cutout with sloping sides; all lines are solid to show that they are to be cut.

The upper tab should fold out.

The lower tab should fold in.

Ah, no.

Whilst i used CP'sscript, i designed my own closure.

> I just thought there was an additional slot joint where you fold that triangle on the end

No, the folded triangle is simply to reinforce the edge of thin foils to stop it bowing out.  In thicker foils, this may not be needed, or may be a simple, single fold.

Hi CP,

Although I have a clone e-mail from you, which I needed my sons computer skills to sort out the script, my computer skills are not upto understanding a fissure script and I don't live that near my son. Are there draughtsman details around? I made my first cone from info from bplite but that setup makes a  cone higher than yours and even even if I change it to a fissure by cutting it down I dont think it will fit in my MSR Titan pot so if there are some plans about I would like to have another go. I have made three.

> I wasn't crazy about the interlocking teeth design of CP's fissure and I like trail design version so I decided to go that route.

Interesting.  Most people who've responded say they think the Flissure joint is better than TD's Fissure.  Given that the latter involves what I consider to be ugly pop rivets, I tend to agree with them.  The overlapping tabs work well, and I think will result in a more stable cone, since the upper part cannot pop away from the lower part (i.e. the mated Flissure behaves very much like a single-piece clone).

I've recently seen one YouTube video of assembly of the Fissure joint (I was trying to find out what the Fissure joint looked like, having never seen it), and it looked quite fiddly; I can unpack and assemble a Flissure cone in under 45 seconds...

But the script is there to play with, so if you want to copy TD's Fissure joint, feel free (provided you're not in the US...)

> parameter from 5 (the default setting) to 4.85. and then printed out the top.

I'm not sure why you changed the slope parameter; did the cone not fit in the pot at slope=5?

> my computer skills are not upto understanding a fissure script

SD, you don't need to understand the script.  All you need to be able to do is use a simple text editor (Notepad, for instance) to change the pot and burner values in the script.  If you can use a forum, I'm sure you can use a text editor.  That's provided your son installed Ghostscript & GSView.

As for a draughtsman's approach, it's quite simple:

draw a side view of your pot and burner, with the burner flame gap (i.e. pot 'floating' in the iar above the burner).

draw in the desired slope of the cone, from the top outer of the pan, and extend this line to a point above the centreline of the pan (the cone apex)

draw a seimi-circular arc from the cone apex to the base of the cone sidewall (where the cone meets the 'ground').

draw a semi-circular arc from the cone apex to the top of the cone sidewall (where it meets the pan).

(if you want a Flissure version, draw a third arc halfway between the top and bottom of the sidewall, and fourth and fifth arcs 10mm above and below this centre line).

cut out the semi-circular sidewall, and form a conic section.

adjust the overlap until your pan just sits nicely inside.  mark the overlap point.

now unroll the cone, and mark on the joint details.

Thick paper prototypes are good; e.g. plain wallpaper.