- Sep 10, 2014 at 12:10 am #1320771
@ryanLocale: Northern Rocky Mountains
Companion forum thread to:Sep 10, 2014 at 5:50 am #2134120
James MarcoBPL Member
@jamesdmarcoLocale: Finger Lakes
Thanks, Roger. The little stove is great!
I do not believe you will need the canister stand. Many of the cans have junk in them. By simply setting them on the main valve, they tilt slightly forming a trap for that stuff. You cannot quite empty a canister in liquid feed mode, but neither do you quite want to. Flipping it upright will empty the remaining few grams without the dirt entering the valve system. Actually, a rather good design, if inadvertent.
I often use an old 1.8L pot for boiling/cooking when camping with the family. This is where the wobble gets kind'a bad. The FM300 burner is connected to the center of the stove, doing great for support, but also placing all stress on the center of the legs. The slight wobble at the center, translates to a larger wobble at the top pot supports. Even the "U" pins and seperate base piece do not eliminate this. It needs more rigidity. The fold on the legs should continue to the washer on the leg mount for maximum strength in this area. The wider bolt connection you mention for the legs will overlap except for one leg at the bottom. The bottom leg can be reinforced with a fold on the opposite side extending by the bottom. This means some carefull machining for the thickness of the metal, but you do this anyway (likely by sanding/grinding.)Sep 10, 2014 at 9:32 am #2134189
John YatesBPL Member
If you use the pliers pictured in the photo near the top of the article be warned that they may bend anything flimsy or heavy that you try to lift since they don't have much contact area with the thing you are lifting. I found this to be a problem when trying to lift a windscreen made out of aluminum foil. My MSR pot lifter worked OK on the windscreen, but the pliers bent it. Also, lifting a pot full of water with the pliers might cause the top of the pot to be bent. My pot is an MSR 1.5 l titanium pot and doesn't get bent, but be careful of other pots.Sep 10, 2014 at 5:28 pm #2134358
Finally I had the opportunity to test the FMS 116T RC version on snow.
Short version :it works but be VERY careful with it.
I had already tested the liquid feed bit at home and it surprised me how well it worked compared to my other stoves with pre-heat.
(smooth transition from gas to liquid feed no stuttering)
So given that I was alone at camp for a while I placed the stove on the kitchen bench of the hut , put some water inside and then by inadvertently brushing against the pot the whole set up fell over.
FIRST LESSON :make sure those tiny legs are spread correctly !!!
Anyway I did a few boils after that mostly on snow with the gas canister sometime upright and other times on its side.
The next day I had it set up as you see in this photo
when a flame came out from the top of the canister (that is a good indication that something is wrong…) very quickly it went from MSR Simmerlite priming flame size to "holy crap the canister is going to blow up-think really fast" situation !!!
Fortunately I had a lot of soft snow about* so I just buried the stove and canister under snow and managed to turn the above canister lever to the off position (on the third attempt, it was still shooting flames during the first two.
SECOND LESSON : make sure that the spider connection (hose to canister) is done correctly !!!!
Examining the set up later on, I realised that somehow the spider connection rotating lock had moved losing the tight seal.
*if that had happened in the early morning when our snow is iced-up I would have had to through the canister in the distance hoping not to get too burnt doing that.
I must stress that both accident were USER ERROR caused, still it was not all that difficult to do.
BTW, because I had forgotten to make a base for the stove,the day before the trip I coated a piece of pressed board with silicone and used some curtain wire hooks to keep the legs in place.
I will change it to something safer when I get around to it.
The stove still works as if nothing had happened to it.
As a point of reference, my competence with gas stoves is in between moron and almost capable.Sep 10, 2014 at 6:44 pm #2134381
Rick MBPL Member
delSep 10, 2014 at 7:34 pm #2134398
You are very welcome, Rick.
I believe that constipation is the start of many health problems so I am doing my bit to counteract that.Sep 10, 2014 at 8:32 pm #2134413
Gordon BedfordBPL Member
@gbedfordLocale: Victoria, Australia
I used it up near Kosciusko on a ski tour. Worked great with temperatures down to -7 C according to our thermometer. Have used it in milder conditions. No worries.
I used a piece of glass fibre woven material as a base instead of a board. This doesn't slide around on snow and stops the legs moving.
I made up a little tool similar to the MSR multi tool. Basically a bit of stainless sheet metal with various spanner sizes cut into it to fit the nuts on the stove. Haven't had to use it out in the field. Also found a bit of copper electrical wiring to act as a jet pricker. Used it when a blockage occurred on my first test run. Not sure what caused the blockage but there have been none since.
I also no longer bother with an inverter stand after trying various things like the ends of PET bottles.Sep 10, 2014 at 8:58 pm #2134424
Forgot to mention….
up there I met another guy that has a Roger Caffin stove ( so much for rare items…)
He has had a good run with his including melting snow and cooking with it, so do keep in mind my warnings but the stoves do work
he has the FMS 300 type.
This guy (Icefest) is very much into UL and doing crazy walks so maybe a bit more attuned to it than me.Sep 10, 2014 at 11:52 pm #2134446
Thanks for all the comments. I will try to respond.
James M: yes, a 1.8 L pot might be a bit big. My big pot is 1.5 L I think. Folds on legs: If I have a large forming press and custom dies, I could do this. But not without. Btw: no sanding or grinding used: all CNC milling.
John Y: good point about the strength of the grip of the pliers. Much care would be needed. I use an aluminium pot lifter.
Franco: 'make sure those tiny legs are spread correctly !!!' YUP!
'make sure that the spider connection (hose to canister) is done correctly !!!!' Er … yes, but I bet you won't have that trouble a second time?
'managed to turn the above canister lever to the off position (on the third attempt,' That is exactly what the off valve on the canister is for! When the lever says 'off', the Lindal valve is SHUT.
Gordon: 'when a blockage occurred on my first test run' I bet it was some aluminium swarf. Sorry about that. Try a paper filter disk under the jet – but odds are it won't happen again.
Summary so far
Large pots are wobbly. Acknowledged – but I had to play with what stoves I could get at a reasonable price. I was very fortunate in that I was able to buy 100 of them from Fire Maple direct at an acceptable price.
I have now sold the last stove I have made up. I may or may not be able to make a couple more. The problem is that I am running out of PFA tubing and SS braid for the hose, not to mention stoves (or burners). To go much further I would have to buy another 100 stoves, another 50 m of tubing, and another 100 m of braid. (Huh? Yes, the braid gets shorter when it goes over the PFA tube. Its measured stretched out.) Are there another 100 customers? I don't know.
RogerSep 10, 2014 at 11:58 pm #2134449
icefest From AustraliaMember
Hey Franco and co.
I've use my 300T RC edition. In Tasmania over summer and for a week in the Main range (amongst others). I've probably burned about 2kg of gas with it by now.
I've spilled a bit of food myself, usually that was due to using a large-ish pot. The wobbly-ness is due to the legs flexing just outside the brass anti-balling washers.
I've had no problem melting snow, I used a snow shovel as the base, with an aluminium wind-shield. The windshield helps keep the pot from tipping over. It works fine, even when left out at -8 overnight.
It's generally my go-to stove for trips where it may be colder than 5°C. I haven't had any bothersome issues with it (other than a few moments of idiocy).
I have thought about the possibility of scavenging a shaker valve insert from a Whisperlight in case it gets blocked but haven't asked Roger about it yet.
PS: That wasn't even a slightly crazy walk, and I'm nowhere near as UL as Hendrik Morkel and other UL-greats.Sep 11, 2014 at 12:30 am #2134454
Shaker valve – gut feeling is that you don't need it. If you have put anything like 2 kg of gas through it, by now the interior will be CLEAN of any aluminium swarf! Yes, you could get blockages from dirt out of a canister, but again, if you have put that amount of gas through with few problems, I wouldn't bother.
What I WOULD do is to review the comments I have made about filters: a 6 mm one under the jet and optionally an 8 mm one between the canister cam and hose connector. The one under the jet is a good insurance.
CheersSep 11, 2014 at 4:26 am #2134466
Gordon BedfordBPL Member
@gbedfordLocale: Victoria, Australia
I took your advice after the first blockage Roger and cut a little disk of filter paper. I did have difficulty cutting such a small circle. Do you have any advice about cutting a replacement?Sep 11, 2014 at 8:47 am #2134517
Tjaard BreeuwerBPL Member
@tjaardLocale: Minnesota, USA
I love your relentless pursuit of functional excellence in items like stoves and tents, as well as your excellent discussion of the proccess.
Somehow I missed the previous article, and therefore did not order one then. Please consider this a vote for another run, even if it has to be a bit higher price.
Perhaps I missed it, but how do you prime the stove in very cold weather (let's say < -25C )?
TjaardSep 11, 2014 at 4:19 pm #2134657
> I did have difficulty cutting such a small circle. Do you have any advice about
> cutting a replacement?
If you can find some 1/4" steel tubing (or 6 mm), cut off a small length and sharpen the end. Stick this in a drill press and 'cork bore' disks out of a coffee filter. Use a softish backing – pine wood works. Google 'cork borer' for images.
Many commercial cork borers sold for use on corks are only brass. Surprisingly, that is probably not hard enough for cutting thin filter paper.
At the worst, drill a 6.5 mm hole in some metal and use that to mark out the circles, then scissors. Not so hard when you have a guide line. Holding the disk with tweezers as you trim it down to size helps.
CheersSep 11, 2014 at 4:47 pm #2134662
> how do you prime the stove in very cold weather (let's say < -25C )?
With very great difficulty.
At -25 C it is likely that you will get no gas out of the canister. At that temperature the liquid fuel is so cold it does not generate enough pressure to force gas out. For more information on this you should read our article on Cold Canisters.
The best solution is to keep the canister a bit warmer than ambient. You can keep your water bottle warm in your pack with the heat from your back. Keep the canister and the stove there as well.
CheersSep 11, 2014 at 5:40 pm #2134678
Michael GillenwaterBPL Member
@mwgillenwaterLocale: Seattle area
Using fibre glass cloth as a stove platform in the snow is brilliant! I've been looking for a light weight solution and that is it.Sep 20, 2014 at 3:24 pm #2136465
Chris HorsfieldBPL Member
My experience is that the large lockout can be dispensed with. If the pot supports don't line up 5 minutes with some abrasive paper will fix that. You get plenty of torque tightening this connection by gripping the stove and the result is at least as tight a connection as the lockout tightened with a minimal wrench. Makes the stove lighter too.
ChrisSep 20, 2014 at 8:01 pm #2136501
> 5 minutes with some abrasive paper will fix that … Makes the stove lighter too.
Can't argue with that. :-)
CheersSep 24, 2014 at 1:35 pm #2137275
Have only had a few chances to use the stove, and none in winter yet, and thus sorry for not having given any beta feedback before now. Will be testing it quite a bit more this winter.
Great follow-up article and comments- very helpful to read. I for one do hope you build more. It’s a great design, and I’ve been showing it off to all my ultralight buddies and telling them to buy one.
Here are a few additional thoughts:
Windscreen: Rather than inverting the caldera windscreen, I found that when using a larger 1.3L pot (which I would typically use in winter ski tours to make melting snow easier, that using the AGG Caldera Cone right side up works great (per picture below). I did cut a small notch out of the bottom of the Cone for the fuel hose to fit through more stably, but didn’t really need to. Second advantage of this setup is that the stove is really stable using the windscreen. Absolutely no worries about tipping over the pot. When the pot is fully seated in the windscreen, the stove bottom does protrude about ¼” below the bottom of the windscreen, but since the stove/windscreen fitting is tight, it’s not a problem to just move the stove a bit up. In the snow, it wouldn’t be an issue either way. I imagine using a stove base will be very important when using the windscreen in snow to minimize melting beneath the stove given the lack of heat dissipation. Also, you have to get your flame dialed in before using the screen, as you can't of course see it anymore.
Stove base: For a stove base, I used your idea, but instead of the wooden board, I used a small REI Campwear Cutting Board (2.4oz). They are thin and made of plastic. Notched out holes for the bottoms of the stove legs (probably didn’t need to) and holes for the titanium stakes. Works great- thanks for the idea. (see pic- no, I didn’t actually use it right next to a bush- just placed to demo the setup) It’s also a nice light food prep/cutting board, although since I do freezer bag cooking, I’m not doing any of that.
Stove storage: No one has mentioned stove storage yet. I am concerned about accidentally kinking the fuel hose, so safe storage in the backpack was an issue for me to puzzle over. Was also thinking about how to make something to hold the canister upright better. When experimenting with the Caldera Cone, I tried fitting it all into the plastic AntiGravityGear Caddy Sack kitchen canister. Perfect – the stove, windscreen, plastic spork, and lighter all fit inside! Should I have any concern about the degree of bend in the hose?
I will admit to still being concerned about kinking the fuel hose though. Perhaps some spring pressure fitting to connect/disconnect the hose from the stove body for safer storage?
Inverting the canister: I was about to make a holder using a soda bottle, but the cup part of the AGG Caddy Sack container works well enough to hold the canister upside down- especially if pushed slightly down into the snow (see first pic), so that eliminates carrying an extra thing. And per James Marco’s point, having it a bit sideways probably keeps the residual canister gunk from coming out.
IvarSep 24, 2014 at 1:45 pm #2137277
Bob GrossBPL Member
@b-g-2-2Locale: Silicon Valley
"AGG Caldera Cone"
What is that, and how does it relate to the Trail Designs product?
–B.G.–Sep 24, 2014 at 2:53 pm #2137291
Point taken about the Caldera Cone, BUT there are two risks to watch out for there.
The first is that the stove may get MUCH hotter when enclosed like that – how hot i do not know. You really don't want to go over 200 C.
The second is that the air flow is now inhibited a bit, which may lead to increased CO emission.
So much larger slots at the top might be a good thing all around, if you want to use the Cone with a canister stove. Caution: I have never tested that.
The plastic base board – yeah, a good idea, but it may soften and even melt if used with the cone. Caution here!
Hose kinking: I have not tested this to destruction, but the curvature your pic shows (with the stove in a caddy sack) should be fine. The PFA hose I selected is very robust and resistant to kinking – that was considered. As a rule, I would try to avoid any bends with a RADIUS of less than 25 mm (1").
Tilted canister – yeah, good idea.
CheersSep 24, 2014 at 3:03 pm #2137296
My mistake. Forgot that those are Trail Designs products. I get them from the AntiGravityGear website.Sep 24, 2014 at 4:04 pm #2137318
Thanks for the cautions- I'll definitely be mindful of overheating the thing. Was thinking about CO emissions and cutting out some larger vents in the screen- you've convinced me for both reasons.
Hadn't really thought through the whole windscreen heat and potentially melting plastic base issue. On ski tours I'd typically cook in the well-ventilated but not usually windy tent vestibule, and so would just use the base as a snow platform, and do without the windscreen. But if I ever did use both, I'll be you're right, it would melt. Same with the plastic on the stake tops. Gonna cut some holes in screen and do some testing.Sep 24, 2014 at 4:23 pm #2137326
That's why I went for 3-ply. Readily available, insulating, light-weight, non-melting, CHEAP …
CheersSep 24, 2014 at 5:09 pm #2137333
That's why you're the engineer! I probably shoulda just done what you did right off the bat.
You must be logged in to reply to this topic.