Improved SUUL canister stove

[Tony Beasley]

After weeks of rigorous lab and field testing of my SUUL stove the pot stand proved not to be up to handling the higher temperatures of the hotter flame produced from the gas flame, especially when using my JB 550 pot. After much thought I redesigned the stand and now the stove seems to be working very nicely, it even survived some rigorous field testing on the weekend. The pot stand can now handle two liter pots. I have also redesigned the fuel line to be more in line with standards, this also fixed some minor problems but added some weight.

The stove is now a bit heavier at 16.8 grams with another 9.8 grams for the Coleman Max canister adapter.

Tony

Latest SUUL stove

With adaptor

Top view

In the field

[Roger Caffin]

Ahhh, Tony

Your stoves make mine look so big and heavy! But I don't have an NC mill. Sigh!

I do like the little brass crimps over the ends of the fuel line though :-)

Some recent efforts:

Edge burner, with local valve for fine control, on/off valve at inverted canister, and Ti wire stove base (no pot supports yet):

Compact side-wall burner using perforated SS sheet:

Cheers
Roger

[Tony Beasley]

Hi Roger,

Thanks for the pictures of your stove projects, it is good to see what other myog stover's are doing. The edge burner looks a nice design. How efficient is the side wall burner stove.

A NC lathe and mill would be nice, I made the pot stand using a lathe and using an indexing head on a mill.

The ferrules are machined out of some brass and crimped on by making a crimp by drilling a suitable size hole between two pieces of steel and then used the crimp to squash the ferrule in a vice, worked well.

Tony

[Roger Caffin]

Hi Tony

Yes, the edge burner has some appeal, but as it stands (in the photo) is a little delicate. But then, it was made of light Al shim, so no wonder. The big danger is that a gap – any gap, can be created by distortion and it could be over about 1.5 mm wide. When this happens the flame can get through and burn inside the head. Ahhh – no thanks!

But there are ways around that problem. I just haven't got to testing them yet. (Think hot-stamped Ti sheet.) Most of my time recently has been spent in getting a stove base for a liquid feed which does not need that preheat tube going up and down. I now think it is possible, but I need to do some more testing to eb sure.

The side wall burner using perforated metal is a neat idea – it avoids me having to drill lots of little holes! A problem with it is finding suitable perf metal. 1 mm thick SS with 2.5 mm holes is not quite what I was looking for. 0.25 mm thick SS (Ti?) with 1.5 mm holes and an open area of 40% would be nice – but it does not seem to exist.

However, the design does have a disadvantage in that the flames run up beside the wall, which can therefore get very hot. If the metal gets too hot the gas starts to decompose via a different path from normal, and the flame turns a translucent orange (glowing carbon atoms). Some commercial stoves do have this characteristic – eg Jetboil Helios at low power.

Indexing head … I do have a small dividing head – an MYOG job generously given to me, but it is small, has a large overhang, and is not very stiff. I may have to buy a better one.

Crimping – I found that a hex crimp tool for coax connectors had a suitable insert, and I have been using that. A circular crimp tool is slightly better of course.

Contributions from other stove makers would be appreciated. Surely there are more than three of us in the world?

Cheers
Roger

[Tony Beasley]

Hi Roger,

>When this happens the flame can get through and burn inside the head. Ahhh – no thanks!

This has happened to me too, especially when using the JB 550 pot, I solved this by putting some fine wire mesh inside the burner head (Davey lamp principle).

>Most of my time recently has been spent in getting a stove base for a liquid feed which does not need that preheat tube going up and down. I now think it is possible, but I need to do some more testing to eb sure.

I would like to do away with the pre-heat tube but I have done some testing of your ideas on this without much success, for now I will stick to the reliable pre-heat tube but will continue to look at other ideas.

>The side wall burner using perforated metal is a neat idea – it avoids me having to drill lots of little holes! A problem with it is finding suitable perf metal. 1 mm thick SS with 2.5 mm holes is not quite what I was looking for. 0.25 mm thick SS (Ti?) with 1.5 mm holes and an open area of 40% would be nice – but it does not seem to exist.

I personally think that side burner stoves are less efficient than top burner stoves but have not done enough testing to prove it.

>Indexing head … I do have a small dividing head – an MYOG job generously given to me, but it is small, has a large overhang, and is not very stiff. I may have to buy a better one.

Hare and Forbes have some cheap indexing heads but I have not seen their quality.

>Crimping – I found that a hex crimp tool for coax connectors had a suitable insert, and I have been using that. A circular crimp tool is slightly better of course.

I looked a BNC crimping tool but decided to make my own.

>Contributions from other stove makers would be appreciated. Surely there are more than three of us in the world?

I would also like to se some more canister stove makers work. I know a few that are attempting to make canister stoves but I have not seen any results yet. I know someone from Canada that has just started making canister stoves and is getting some good results but he posts on another forum.

Tony

[Dan Yeruski]

Hi all, there are some of us that are trying to make canister stoves but are not succeding, like me ;)

Materials are stainless steel and aluminum. Not trying for lightweight yet. Just need to get the air fuel mixture right first, hahahah right!!!!!

I'm having fun, and that's what's important.

Nothing Ventured Nothing Gained

Here are some photos of my recent failure.

The first four photos are of the burner "head" showing how thin it is. Just seeing how it works under direct pressure, no air mix.

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[Tony Beasley]

Hi Dan,

Welcome to the canister stove making club, I think you will find it bit more challenging than alcohol stove designing and making.

After looking at your pictures I would guess that your problem is the material that you have in the burner head is restricting the flow of the gas/air mixture, try removing it, Roger’s burner head is a similar design and I do not think it has any thing inside it.

Tony

[Franco Darioli]

There are several reasons why most would-be alcohol stove makers ( like me occasionally but not Zelph) don't even attempt gas stoves. Tony's and Roger's models set the standards far too high to even entertain the idea. Shame on you both.

I really like Roger's side patterns possibly the prettiest flame I have seen.

Tony, aren't those cartridges butane only ? I am considering a gas stove for winter but butane seems to be out for that ( ?) although if I am not mistaken they are much cheaper than the standard type.
Franco

[Dan Yeruski]

Hi Tony, thanks for the welcome. Glad to be in the club. You and Roger are our mentors, our inspiration =)

I'll make another head and do as you suggest. The one above has been welded to the point of no return =)

I had 2 pieces of mesh between 2 pieces of solid sheet spot welded together. The idea came as I was driving to a campsite. I may try a pepper shaker cap for the next try.

I'm tossing around the idea of using a "Shrader Valve" for the working mechanism for the on and off valve and fine tuning valve. It has some nice features.

[Tony Beasley]

Hi Franco,

>Tony, aren't those cartridges butane only ? I am considering a gas stove for winter but butane seems to be out for that ( ?) although if I am not mistaken they are much cheaper than the standard type.
Franco

According to Roger's FAQ the Coleman Max canisters have the highest propane (40%) content of any canister mix so they are the best in the cold. I have had them working at around -16C.

Tony

[Roger Caffin]

Hi All

Out this weekend, field testing YACS (yet another canister stove)… Learnt a lot, including the need to ensure I don't lose the canister-sealing O-ring! Ah – but I did have spare O-rings and a spare stove too… :-)

Yes, the very flat burner head Dan shows will restrict the gas flow far too much imho. Yes, my version is ALMOST empty inside, but the volume is much greater.

> possibly the prettiest flame I have seen
Yes, very pretty, but I have reservations about how much heat gets coupled to the bottom of the stove that way. I think it will be better to have the flames pointed upwards a bit more. However, building and testing the side-wall burners has taught me an awful lot about the internal gas flow.
I am now learning how to hot-stamp thin titanium sheet for the burner head. It can be done – with a long spoon …

> Coleman Max canisters have the highest propane (40%) content of any canister mix so they are the best in the cold. I have had them working at around -16C.
Yeah – they should work down to -26 C with a little care. I would prefer to not test them down there though …

Below that, I think one needs to move to straight propane – Coleman bottles, but heavier gauge steel.

Cheers

[Tony Beasley]

Hi Franco,

>There are several reasons why most would-be alcohol stove makers ( like me occasionally but not Zelph) don't even attempt gas stoves. Tony's and Roger's models set the standards far too high to even entertain the idea. Shame on you both.

It is not only mine and Rogers fault, you can add all the other bp myog'ers that make high quality gear, I often feel intimidated by the quality of gear that is made with little or no experience and equipment.

I will try and lower my standards in future.

Tony

[Tony Beasley]

Hi Dan,

>I'm tossing around the idea of using a "Shrader Valve" for the working mechanism for the on and off valve and fine tuning valve. It has some nice features.

Using a schrader valve is a great idea, I had not thought of that before. It is basically the same design as a lindal valve but it is probably easier to fit into a design.

As I understand it using a lindal valve to turn a stove on and off has been done before by several stove makers, I have made an adapter that does exactly that but I do not like that some gas is lost when turning off as this gas can ignite from the burning flame even from a distance, I have had this happen, it is quite an experience trying to twist a canister while it has flames from it. This problem might be able to be designed out with using a Schrader valve.

Tony

[Roger Caffin]

I am not sure how one would use a Schrader valve in practice, or where. You can't buy canisters with Schrader valves, so unless you make your own canisters that would seem to be out? Unless you had the Schrader valve after the Lindal valve – but why?

I may be slow to understand, but I can't see any benefit to trying to use a Schrader valve in place of a needle valve for the flow control. The Schrader is basically designed to turn OFF, which is not what you want for a fine simmer.

Anyhow, both the Schrader valve and the Lindal valve are basically the same thing. The internal pressure provides most of the driving force to push the plug into the socket and shut off the flow. Both designs have a small internal spring, but that is mainly for the low-pressure end of the range, just to get things started.

Yes, you can use the Lindal valve as a flow control. It is a bit 'iffy' and very coarse to adjust. If you rely on the screw thread on the canister, you will wear out the connector part very quickly imho, as the thread on the canister is VERY poorly formed. (Yes, I have tried it, and yes I have worn out the screw thread on a stove.)

> it is quite an experience trying to twist a canister while it has flames from it.
Oh SH*T!
NO WAY! (Not in MY tent anyhow!)

Cheers
Roger
(PS: sorry if I come across as a bit cautious, but experience is a great teacher!)

[Roger Caffin]

> I will try and lower my standards in future.

kaboom!

[Franco Darioli]

Standards…
No worries, keep at it, I wasn't going to try anyway.

Never noticed the mix of those Coleman cartridges. Thanks for that. Must check the availability now.

A SUUL remote canister stove that uses a Ti cone as a stand/windshield and can work below freezing (and without twisting cartridges) ,sounds very interesting to me…..
Franco

[Tony Beasley]

Hi Roger,

>> it is quite an experience trying to twist a canister while it has flames from it.
Oh SH*T!
NO WAY! (Not in MY tent anyhow!)

(PS: sorry if I come across as a bit cautious, but experience is a great teacher!)

That is why I have gone to the Coleman Max canisters, almost no gas escapes when removing the valve.

Tony

[Dan Yeruski]

The Shrader valves have possibilities. They are readily available for DIYers and may be available in aluminum.(not reasearched yet) The threads on my stove are of the Shrader size as the nuts used also are from stainless steel shrader valves. I have alot of valves left over from a past experiment. Brass is easily soldered and worked. If the valves work out, were ahead. Nothing Ventured, Nothing Gained

My fire extinguisher would be first choice attempt at a canister shut off ;) Your experiences are valuable teaching aides, thank you.

[Roger Caffin]

Hi Tony

> the Coleman Max canisters, almost no gas escapes when removing the valve.

I have noticed this as well. There are very small differences between brands (of stoves and canisters) in the length of the central valve-actuating pin. When the pin is longer than it should be *for that canister*, then you can get a slight leakage as you unscrew the connection. So I always do it fairly fast.

Of course, if the pin is too short, you can't get gas out of the canister! But I have not had that as a serious problem yet.

Drives me mad, trying to come up with a universal design which will handle all of them! AND be easy to operate at the same time.

Cheers

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