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Kovea Spider conversion

PostPosted: Sun 24 Mar, 2013 7:55 pm
by Mark F
While this doesn't match Quicky's esbit adventure for weight, it provides a different perspective on the way gas stoves are configured.

I received my Kovea Spider invertible canister stove on Friday with the intention of lowering its weight. My first job was to strip it down and find out where the weight was.
IMAG0157s.jpg
Kovea Spider components

As expected its in the stand/pot support and the brass disk that keeps the whole thing together. Remove these and save 75 g.

I have looked at units like the Caldera Cone and wondered about suspending a gas burner from the pot supports rather than relying on Esbit, metho or wood. I recently replaced the handles on my main pot, a 900ml Ever New Ti, with a bale handle (40kg stainless steel wire for a 2 gram handle saving 15g) and thought the wire and crimp method should work well at absolutely minimal weight. I made a rough X shaped steel piece which attaches under the burner head where it screws into to mixer tube. I then took my existing Ti windshield and added two pot rests onto which the X piece is connected with the stainless wire. This adds back 18g of the saved weight leaving me with an invertible canister stove with full windshield at 125g.
IMAG0159s.jpg
Modified Kovea Spider

The whole thing, apart from the pot supports fits in my 900ml pot with a 230g canister.

Re: Kovea Spider conversion

PostPosted: Mon 25 Mar, 2013 1:35 pm
by Franco
just thinking aloud here...
I am a bit worried that the wire will become brittle and snap after a few burns.
The problem would be of course if it happens when in use.

Re: Kovea Spider conversion

PostPosted: Mon 25 Mar, 2013 1:54 pm
by Mark F
Yes Franco, plenty of testing needed. One thing in the design's favour is that the burner is fully enclosed in the windshield and the valve is on the outside.

Re: Kovea Spider conversion

PostPosted: Mon 25 Mar, 2013 2:44 pm
by Franco
Hi Mark
I am interested in that stove too because I think it is the lightest reliable winter gas stove.
By winter I mean our -5 to -10 winters...
I like the compact folded size too.
I made, a couple of years ago , a stripped down version of a Chinese stove replacing the legs with wires to support the stove having in mind the windscreen/peg support for the pot.
Maybe something like that can be done with your Spider.
A piece of plywood under those legs and the windscreen would be needed for that.
Image

Re: Kovea Spider conversion

PostPosted: Mon 25 Mar, 2013 3:26 pm
by Mark F
It would be quite easy. If you have a look at the pre-heat unit you will see two screws protruding from the bottom that attach the brass base plate. As I don't have a workshop or welder etc (but I do a sewing machine) let alone a lathe so my abilities are limited - I need to find very simple solutions.

Re: Kovea Spider conversion

PostPosted: Fri 12 Apr, 2013 1:45 pm
by Mark F
I have just done 5 burns with the modified Kovea and as expected the nylon coating on the wire burnt off but the wire, having been red hot for about 4 minutes each time and cooled in between burns. The wire does not seem to have become brittle. What did happen was that the crimps loosened. It looks like the crimps supplied with the wire are aluminium - not stainless. So the loosening may be due to the nylon burning off or may be the effect of the heat on the aluminium. I have tightened them up and will run a few more tests. Perhaps I can find stainless or brass crimps.

Re: Kovea Spider conversion

PostPosted: Fri 12 Apr, 2013 1:48 pm
by Strider
How many strand is the wire? Splice it?

Re: Kovea Spider conversion

PostPosted: Fri 12 Apr, 2013 5:21 pm
by Mark F
Splicing it would be the work of elves. The wire is under 1mm diameter and has 7 strands. I think knotting it may work.

The individual strands make a perfect jet pricker. They are quite stiff being stainless steel and easily fit down a gas jet. I will put a 2 cm length of the wire in my repair kit with about 6mm of the nylon coating removed from 1 end giving me 7 jet prickers.

Re: Kovea Spider conversion

PostPosted: Tue 07 May, 2013 6:08 am
by hikin_jim
Hi, Mark,

Thanks for calling this thread to my attention. FASCINATING -- and fearless. I'm a bit more timid I guess, especially when it comes to carving up one of my favorite stoves. But by removing the legs and the brass disc, you remove nearly half the weight of the stove! That's fabulous. The legs must be the great majority of the weight, yes? The disk can't weigh too much by itself. 20g? 30g? I suggested to Kovea in an email that titanium legs would save a lot off weight. We'll see if they listen. I'm not holding my breath.

But eliminating the legs entirely is a better idea still. Use the windscreen as both the windscreen and the pot support. Using a Caldera Cone or Ti-Tri Cone would add even greater efficiency.

How is it performing in field testing?

HJ

Re: Kovea Spider conversion

PostPosted: Tue 07 May, 2013 7:53 am
by Davidf61
Various types of knottable s/s wire and stainless/brass/alloy crimps can be found in any good [ie serious] fishing tackle shop.

What about 2 more titanium tent pegs to somehow hold the burner? Take the little star shaped bracket, chop off 2 legs, roll the other 2 up to form little tubes and slide the tent pegs thru, or something similar.