Jun 3, 2019 at 8:34 am #3596013Jun 3, 2019 at 11:11 am #3596018
Sorry Roger, I don’t have any of the specific maths on those shapes. I find Pinterest a good source for images, these days.Jun 3, 2019 at 11:25 am #3596019
Can’t CNC that either … :)
But, you know, that squid did look ‘rendered’, so maybe someone HAS done the maths. Hum …
CheersJun 3, 2019 at 11:34 am #3596020
That image is more an octopus, than a squid; I was being too clever. Some of the images at that website are rendered. I never got into that level of geometric visualization, FEM et al., though many papers I read these days incorporate such techniques. But nature has already been there, done that…Jun 3, 2019 at 11:38 am #3596021
Robert…. darkroastedblend Challenged my brain and sense of orientation to the max.Thank you! :-)Jun 3, 2019 at 12:10 pm #3596023
Ahhh, that animation on darkroastedblend comes originally from
Imaging maths – Inside the Klein bottle
by Konrad Polthier
Check the animation Half of a Klein bottle with Möbius strip at
How do you capture those animations Dan? I can’t seem to in iOS.Jun 3, 2019 at 12:31 pm #3596024
Use your mouse to place cursor on the image, right click and chose “copy image”, come here to forum and “paste” into reply. I’m using a google Chrome Book as my computer and “google chrome browser”Jun 3, 2019 at 12:31 pm #3596025
The Figure 8-Klein bottleJun 3, 2019 at 12:32 pm #3596026
Thanks Dan. But no mouse in iOS, I would have to switch to my iMac.Jun 3, 2019 at 12:42 pm #3596027
had to google that:
“iOS is a mobile operating system created and developed by Apple Inc. exclusively for its hardware. It is the operating system that presently powers many of the company’s mobile devices, including the iPhone, iPad, and iPod Touch. It is the second most popular mobile operating system globally after Android.”
I learn something new every day :-)Jun 3, 2019 at 1:30 pm #3596029matthew kModerator
Strange how the most rational choice of backpacking fuels ends up being the weirdest thread.Jun 3, 2019 at 5:56 pm #3596056
After I made this windscreen/potsupport/heat exchanger for esbit I got side tracked with the canister stove project……..my bad!Jun 3, 2019 at 10:44 pm #3596088
As Jeffrey might observe, perhaps weirdness lies in the eye of the beholder.Jun 4, 2019 at 9:06 pm #3596221David FranzenBPL Member
<p style=”padding-left: 40px;”>For the Klein Bottle you dont need a CNC. Just a sheet of paper and some glue. And maybe another dimension^^</p>
Jun 4, 2019 at 9:55 pm #3596225
Ah yes, but the challenge …
CheersJun 5, 2019 at 7:37 am #3596323
OMG! Zwitterionic polymerization of ethyl 2-cyanoacrylate (ECA) monomers initiated by dimethyl sulfoxide (DMSO)! And forming macrozwitterions in a propagation loop to boot! That’s the third time this week!
Errr Roger, is that surface more amenable to analysis?Jun 5, 2019 at 8:05 am #3596324
I just KNEW elliptic functions would get in there somehow!
I was trying to invert or solve an inverted elliptic function, but that turns out to be an NP hard problem. Which is why ‘they’ use elliptic functions in cryptography.
And Wolfram Mathworld has the parametric equations for 3D too. How nice. Zeta functions though – ugh.
Programming it would be an utter b*tch.
The web site http://www.minimalsurfaces.blog has some gorgeous shapes.
Meanwhile, back at the Esbit stove …
CheersJun 5, 2019 at 8:26 am #3596326
Ahhh yes, well I can report that the Evernew Ti windshield EBY246 I described at some length (much) earlier in the thread has with use shown a few limitations. Firstly its very lightness can be a nuisance in high wind conditions, as it is very likely to blow away. Secondly (and Dan might be particularly interested in this), use on an uneven surface – e.g. the ground – can be slightly frustrating, as again the light weight does not bend grass or weeds out of the way. Further, there are two parts of either Ti ring where the triangular vent holes mean that there is a relatively narrow strip of Ti along the edge; and this has bent somewhat, and does not want to unbend. Not a deal-breaker; but the design should be improved to provide wider strips near the edge. I would also have paired flaps and slots side-by-side to make a better cylindrical form.
Despite this criticism, and allowing for the fact that I mostly use only one of the two rings and in the narrow rather than the wide configuration (with normally an Esbit 400 mL mug, for my coffee), I’m pretty impressed with the performance. Despite the instability of the Evernew TriveTi Esbit pot support, and alarming wobble of the pot on the stand, it does the job, complete with the Dan Y’s Esbitmiser tray (w/o the lid). In two words, highly recommended.
A further benefit is the plastic – but in this case – very serviceable – bowl and lid the screen is supplied in. Very useful to store the bits and pieces that you want at hand, but are not using at that moment. e.g. fuel, lighter, small bottle of oil, small salt container, wooden stirrer; and of course it stores the 400 mL mug plus everything else needed, including wet wipes to clean after use, save the coffee. I’d be happier if the bowl was cylindrical, but it is a truncated cone, with slight waste of space. If I get some time, I’ll post further photos.Jun 5, 2019 at 10:03 am #3596333
Dan, in your Stormy Weather Stove video above, I was astonished by the absence of vent holes in the windscreen cylinder. Very difficult to assess what is happening, because when the pot is removed, of course there will be an inrush of air/oxygen, so it will burn strongly – but when the pot is replaced – is it still burning strongly? (Mind you, my earlier cut-down Asahi 2L can screen had no holes, just the lowered step for the handle, and the circumferential gap, and it worked well…)Jun 5, 2019 at 2:05 pm #3596346
The Stormy Weather stove is a windscreen/pot support with incoming air holes at it’s base. It supports a handless Toaks 750 pot by it’s top rim. Heat exchange fins keep the windscreen equally spaced around the pot. The tips of the fins support pot rim.
This arrangement is far more efficient than a Cone system.The most interesting thing about it is the speed at which a 14g esbit brings 500ml to a boil.
Esbit users are few and far between and so that is the reason I drifted off to the canister stove skirt design which is a spin off of the Stormy Weather stove. Canister stove users need all the help they can get. Someone needs to design a muffler for them. :-)Jun 10, 2019 at 10:32 am #3597009
Lookin’ good, Dan!Jun 10, 2019 at 7:53 pm #3597071
Thank you Robert. The pot used in the video is a Titanium Toaks 750. The heat exchanger windscreen also supports the pot at it’s ridge. The full size esbit sits at the correct distance to pot bottom.
I hope to get back to this project to give you some of the fantastic boil times for 500ml of water.The heat exchange fins are working wonders. :-) Too many irons in the fire ;-)Jun 10, 2019 at 8:30 pm #3597073John KBPL Member
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