The Evolution of a Winter Stove – Part 3

[Jerry Adams]

Butane – heat of evaporation 320 kJ/kg, heat of combustion 45,000 kJ/kg

takes less than 1% of combustion heat to evaporate

shouldn't be significant

[Roger Caffin]

Hi Paul

Um and Oh. My own series of articles. Oh Dear. :-)

OK, part of the problem there was that we were comparing apples, oranges and the odd bunch of grapes. Some of the remotes had rather large burners which were less efficient for a given pot diameter than the smaller uprights. Some of the remote burners were just a bit strange too. I am going to blame most of the variation between the two classes on flame or burner diameter, as I noted in that article:

What is surprising is that the Remotes are generally less efficient (blue diamonds) than the Uprights. We believe that part of the reason for this is that the average flame diameter for the Remotes is larger than for the Uprights, and the flames are therefore closer to the edge of the pot. When the flames curl up around the edge of the pot, you know the efficiency is going to fall, as heat is being wasted.

However, with a remote canister stove based on the FMS116T or FMS-300T (ie mine), we could expect that the performance would be the same since the burner is the same. Perhaps one day, when I have built all these stoves for beta testing, I will get the time to run this experiment and report on it.

Cheers

[M B]

totally agree it shouldnt be significant.

But as I said, when you are losing half your heat to the environment anyway, detecting small efficiency changes only works if you can keep other losses constant.

Or better, completely optimized for each individual stove. Without this, any data has a chance of being invalid.

[Michael Driscoll]

remote canister stove based on the FMS116T or FMS-300T of the 2 models you are selling which would be the quieter running stove… could not remember if it was mentioned in the series or not…

[Roger Caffin]

> FMS116T or FMS-300T of the 2 models you are selling which would be the quieter
Oh, very definitely, the FMS-116T version.
I have one or two of those left still.

Cheers

[Roger Caffin]

Hi all

I have to apologise for a bit of a delay in getting the beta-test stoves
built and shipped. Such delays are why I did not want to accept any money
earlier: they happen.

First, the X axis on my CNC machine started to jam. I knew what was
causing this: dust from machining Corain plastic had got past the brush
seal into the oil in the ball-nut. This turned the oil into very thick
grease and the little balls were jamming in their grooves. never again
will I machine any Corian plastic! Fixing this meant stripping the X axis
drive system down, cleaning the double ball-nut out, and rebuilding it.
That includes actually disassembling the double ball-nut itself, cleaning
it, and then putting all the balls back in without losing any. This was
not easy – the machine weighs 240kg (530 pounds) and had to be jacked up
for access underneath, but it was done. I lost a good part of a week here.

Then we had problems with the greywater disposal system we use on the
farm. (No sewer connection on farms.) The washing machine stopped working
properly. You don't argue when this sort of thing happens! Fixing this
took a good part of a week too. Lots of spade work. All OK now.

Then, just as I was getting back to the workshop, I went down with this
year's flu. It was a good dose (if 'good' is the right word): I was out
for about 3 weeks and am only just now starting to get back into action.
Imagine: a tiny 0.01 micron virus able to flatten an adult human being.

Anyhow, I will be back in the workshop pretty soon, working on the final
parts needed to be able to start shipping the FMS-300T version of the
stove. It will take a couple of weeks to have some ready. Then I will
contact all of you who have expressed an interest (by direct email).

Cheers

[Michael Gillenwater]

Glad you are feeling better. And no apologies necessary. Life if full of the unexpected.

[Oliver Nissen]

Roger: I'm glad to hear you weren't flattened under 240kgs of CNC machine, but sorry to hear you were laid flat by a 0.01 microns wide, three weeks long flu virus… And for all your other set backs too.

I received your email, but just wanted to bring to your attention that you'd left your dollars ambiguous! It's safer to assume you're referring to US dollars (we're not going to short change you that way), as opposed to the more economical Australian variety.

My Paypal payment sent! Thanks

[Roger Caffin]

After many weeks of promises, promises, we really do have production at an advanced stage. Andf the 3+ weeks of flu is past.

Here we have a stack of canister connectors with cam valves in place. The next step is to connect up a lot of hoses – one is shown at the bottom.

The green-handled screw-driver at the top is an aid for the aged … :-) Actually, it was getting painful putting the self-tapping screws into the acetal plastic for the retainer plates because the first insertion is a serious thread-forming process, and the handle of the silver screwdriver was really thin. The fat green handle makes that easy.

All the Nalge bottles at the top – bottles of bits to go into the stove. Amazing how many separate parts are involved.

A range of parts. Untested stoves with burners at the left, then untested stoves without burners, a stove body with the new tripod legs, a fan of tripod legs, a handful of canister connectors with hoses, and finally at the right a handful of hoses.

The hoses do not have the filling cord inside yet, and they don't have the essential little internal heat exchanger rods either. They go in when the hose is connected to the stove body. Tomorrow is another day.

The final stage will be testing: pressure testing for leaks, flow testing for the whole system, and then a burn test for each stove to make sure the darn things work. So far I have caught one hose which was mostly blocked for some reason, and one stove which did not burn correctly. The latter had a foreign jet by mistake, and the fuel/air ratio was all wrong.

Cheers

[Roger Caffin]

The first batch of stoves has been assembled.
They have all been pressure-tested for leaks and for flow.
They are now being individually burn-tested.
Next stop, package them all up and down to the post office.

Cheers
Edited to fix date

[Bob Gross]

What calendar are you looking at?

–B.G.–

[Franco Darioli]

2021.
I am glad I put my order in early.

[Rick M]

del

[Drowned Lemming]

Easily explained.
He is in Australia, so is upside down.
A 6 upside down is a 9………………….

[James Marco]

October 6??? OK. You design a stove that is better than anything else. You repair CNC millers. You fiddle with things around the farm. But, you still do that retired thing and loose track of the date. Ahh, well…We know what you mean…well, sometimes anyway. That bug must've really knocked hell out of you. Nope, it must have been all that diggin'.

Anyway, I didn't get a confirmation from you, . I ass-u-me you got the payment. Thanks Roger!

[Jerry Adams]

Neil, you beat me to it…

Australian calendar is upside down

[Roger Caffin]

Hi Jim

> I didn't get a confirmation from you, . I ass-u-me you got the payment.
That's the good thing about Paypal: you get a FULL record of transactions.
And yes, I check Paypal every day and record all payments on my machine too. Yours was recorded.

The date – a simple typo. But it seems to have created lots of postings! :-)

All stoves in this batch have been pressure tested for leaks (100% pass rate) and for flow rate (100% pass rate). They are now being burn-tested for correct fuel/air mix and power.

Cheers

[Roger Caffin]

Hi Rick

> What are the details/specs?
Well, if you read the 3 articles to which this Forum thread is attached, you will find all the gory details.

Cheers

[Rick M]

del

[Erik G]

+1 to Rick M's request for a quick summary of the specs and if/how we could order one. I really want to get my hands on one of these stoves, but I really don't want to have to pay for an article or three just to see how to get it. It's the articles or the stove for this guy! :)

[Michael Gillenwater]

Not to set off a firestorm of my own, but it is only $25 to be a member of BPL and get access to everything.

[Peter S]

This would seem like a good time to support BPL, so Roger can continue his awesome work/articles that we have all benefited so much from…

[Erik G]

Thank you for the kind reminders and advice on how to spend my money. :)

[Rick M]

del

[Peter S]

I'll be so kind and suggest you get a membership AND the stove.

Yours truly! :-)

[Author]

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