World's smallest and lightest fan forced TLUD stove.

[Ray Britton]

Hi Teepee.
No need to thank me for the praise.
As per one of my previous post's, these stoves are far too fiddly for me to use them, by as a designer/manufacturer I can also really see and appreciate the research and design you have put into your stoves

You mention using solar power. Can I ask which solar charger you use. I only mention this as I use a solar monkey/power monkey combo, as I have an Iphone and this is really the only charger that is man enough for the power hungry Iphone.

Although the power monkey would give your battery two or three complete changes, the solar monkey could actually power the stove or batteriy direct while you were using the stove!

Apologies if you knew all that already.

 

[Teepee]

Im using a Freeloader pico.

It is usable, but not ideal. The 75mA Pv cell it uses doesn't cut it, but the unit weighs 56g which is much ligher than most. It will run the fan at max for over 4 hours on a full charge, and over 6 hours running at 3 volts-this is a good voltage for the forge and cooking pasta etc.

I looked at the powermonkey, but decided it was too heavy and expensive for the benefits

With the combination of 3x aa alkalines, the pico and the phone, I can get 20-30 hours runtime-this is plenty for a week.

I'm using an adjustable robotics switching voltage regulator which will take any voltage from 0.5-5v and turn it into 2.5-5v. All I need is a standalone solar panel for direct power, maybe a Powerfilm panel. This is a work in progress, along with the tegs.

 

[Gailainne]

T any joy finding that other TEG manufacturer? the 500 deg C one. And did your van come back loaded from poundstretcher?

Hopefully the rotocraft diamond discs will arrive before the weekend, let you know how they fair. The outer flask mat'l is pretty thick its between 0.49 and 0.55mm according to my digital calliper, that's the 1L flask.

Freeloader have an additional larger solar panel which isn't bad, it means you can leave the 2 small wing solar panels that come with the freeloader at home, it does require direct sunlight tho.

Image from Shewie, you can see the solar panel on my canoe just above the red and white barrel. And no comments on the knees

 

[Teepee]

T any joy finding that other TEG manufacturer?

Not yet, I am still searching

And did your van come back loaded from poundstretcher?

No on that one too, I took ages seeing a potential job and didn't make it, but I'm going in the morning to fetch them, then going to my tool suppliers for some proper cutting discs.

Freeloader have an additional larger solar panel which isn't bad, it means you can leave the 2 small wing solar panels that come with the freeloader at home, it does require direct sunlight tho.

I reckoned this was too heavy, too. It weighs the same as 6 duracells which give about 50 hours of go.

The outer flask mat'l is pretty thick its between 0.49 and 0.55mm

The pound shop special flask says 10 thou on the micrometer which makes it 0.25 mm (I think)

And no comments on the knees

I'm in no position to comment.
Good looking campsite, Btw.

 

[Gailainne]

I keep on forgetting you cart everything in on your back, canoes are great pack carriers , too good actually you bring (I bring) a lot of stuff thats not used, hard habit to break.

Yep we used 40 thou to the mm back when I was an engineering apprentice. That makes your original flask very thin, I've just checked the top of the 0.5l flask and its coming in around 0.76mm thick, that will be double wall, getting closer to yours at 0.38mm.

If I get time this weekend between helping my sister move house I'll mod the 0.5L flask, I got the sunon fans btw, very nice.

The camp site is on a recent trip I did with Shewie and Grooveski on Loch Shiel, really beautiful place.

 

[Teepee]

I have to get a boat myself.
I've been thinking about it a bit recently, maybe it would calm my gram counting down a bit.

I fancy a sea kayak, but I know nothing about them really, other than they float and wobble.

 

[Teepee]

getting closer to yours at 0.38mm

This sounds good, the top should be thicker than the bottom, I imagine they are welded and formed.

 

[Gailainne]

I bought a solar motor along with the TEGs from MUTR, I tried it last night with one of the tegs using a turbo lighter as a heat source, the flame held well away from the teg, surprisingly the fan started working immediately, I may use the larger firebox with the solar motor as a bottom mounted fan powered by a teg or 2 see how that works.

BTW have you looked at RC electric ducted fans? you get spare fans at very cheap prices, precision made for a couple of quid each! shaft diameters may be a problem, but worth a look.

 

[Shewie]

What's a teg ?



and a dim ?

 

[Shewie]

Dims are diams right ?

Not sure about the tegs though, thermonuclear extension grommets ?

 

[Ray Britton]

Hi Teepee.

As per previous post, I HAVE to have the power monkey, as the freeloader is not powerful enough to run an iphone, so weight was just a buggerance I had to put up with

You mention you use alkaline batteries. Is that purely on a cost basis?
Lithiums are lighter than alkalines, and last longer (or am I missing a power regulation issue here), and recharchables will give longer power than alkalines* too, plus can be recharged via solar power on site.

For anyone else looking in, rechargeable batteries have come on in leaps and bounds in recent years, and as an example:
I have a mini TV which will run for 1.5 hours on duracells, but will run for 3.5 hours on high quality rechargeables.

That said, I find duracell batteries over rated, and much prefer energiser ultimate, as they have more power and better positive contacts which fit better, and do less damage to fragile terminals in outdoor equipment.

 

[Teepee]

Gailainne
I bought a solar motor along with the TEGs from MUTR, I tried it last night with one of the tegs using a turbo lighter as a heat source, the flame held well away from the teg, surprisingly the fan started working immediately, I may use the larger firebox with the solar motor as a bottom mounted fan powered by a teg or 2 see how that works.

BTW have you looked at RC electric ducted fans? you get spare fans at very cheap prices, precision made for a couple of quid each! shaft diameters may be a problem, but worth a look.

You have some cool stuff there, looking forward to finding out how it works.

Ill have a look at the rc stuff, its a new one to me. I have looked at cooker fans, but they only come in 12v models-they are heat proof though.

I went to poundstretcher -It has closed down.
I'm going to have to wait 'til monday to go to one in another town.
Asda have 0.5 l flask for £3.00, but it seems much thicker stainless.

Shewie
What's a teg ?
and a dim ?

Teg=Thermo Electric Generator-basically electricity from heat.

Teg- http://en.wikipedia.org/wiki/Thermoelectric_generator

Dims = Dimensions.

Thermonuclear Extension Grommets? Ive run out of those.

Ray- You mention you use alkaline batteries. Is that purely on a cost basis?

Basically yes.
The lithium aa's and rechargeable's have a much lower internal resistance than alkalines and nimh, and so will run high power devices like tv's for much longer. Alkalines are really bad for high power apps, but good for lowish drain apps. This fan is a low power device, and so will run well on alkalines. They all have similar capacities ( ~3000mAh). I have looked at Lithium polymer cells from RC equipment, but these need heavy and expensive chargers. The solar chargers (and mobile phones) we have been talking about do use LiPo batteries, and have the chargers built in, so for me, they seem the best option to date.
I'm with you on the enrgizer v duracell-the energizers do seem to last longer, but I have a stack of duracells I got v cheap.

The other point to consider is the weight- an AA lithium weighs (hideously expensive though) 14g-
an alkaline weighs about 28g and a NiMH is over 32g.

In my Petzl head torch , I can get 4- 5 nights run time from the lithiums, but over 10 with the alkalines.

 

[Ray Britton]

Hi Teepee, and thanks for the reply.

I am always curious as to other peoples equipment choices, as well as always ready to pick up new tips or better ways of doing something

 

[Gailainne]

Update on my 0.5L T clone, here it is, pretty basic atm, held together with heat resistant duct tape

As you can see its powered by a power monkey, (for my iphone), there is a thin layer (1mm or there abouts) of fire cement, your right btw T its bloody heavy, inside the fire cup, and its a sunon 5v fan.
It boiled 250ml of tap water using the primus eta 1L pot in 2.5 mins, using 2 titanium stakes as pot supports.

I switched to 1.6mm stainless wire as pot supports for the second test of 0.5L of tap water in the primus, it came to the boil in just under 4 mins, a bit more smoke early on, but not bad.

Quite impressed, and its a LOT of FUN too.

Stephen

NB I forgot to say, initially the square duct was just fitted into the cowl, however I found that there was far to much air getting into the bottom holes, so I shaped the duct to fit better and added a baffle plate to the bottom of the duct to direct the air upward, it did seem to improve matters.

 

[Teepee]

Fantastic!
I'm glad you are having success, Stephen. Its nice to see another working stove. Your boil times seem to be similar to mine, too.
I have put the stoves on hold for a while-work is too busy, and I've just bought a kayak after looking at your pictures of hammocking and fishing round the Lochs.

What did you use for fuel?-wood or pellets?

 

[Gailainne]

Fantastic!
I'm glad you are having success, Stephen. Its nice to see another working stove. Your boil times seem to be similar to mine, too.
I have put the stoves on hold for a while-work is too busy, and I've just bought a kayak after looking at your pictures of hammocking and fishing round the Lochs.

What did you use for fuel?-wood or pellets?

I used wooden pellets, but at the end I was using small chunks of pine, which worked quite well, as long as you didn't add to much at once, then it cooled down and started smoking. I was getting a 25 min burn time with a full load of pellets from my initial set up, but that was using my canon camera battery as a power source, more omph. The fire cement has come away from the bottom and partially the top, not sure if I want to use it, it puts a lot of weight onto the set up.

Good for you on the kayak, you'll have to post up pics after your first adventure.

 

[Teepee]

I've not tried the fire cement directly on the stainless, I lined the chamber with mica. The fire cement was spread over the mica only at the bottom, as this is where the chamber glows red hot-the mica breaks down at a 1000 deg. I didn't think it would stick to the mica well, but its still there a year later and hasn't flaked at all.
I also made a slurry of fire cement and coated the bottom of the cup with it, so that the mica paper stuck fast to the bottom.

Good for you on the kayak, you'll have to post up pics after your first adventure.

Will do, I can't wait to strap it to me roof and drive up your way, Loch Rannoch and Loch awe are looking very inviting.

 

[Gailainne]

Tsk, with a kayak you should be looking at the sea lochs, if not the west coast itself, but whatever you decide enjoy mate.

I wanted to see what the fire cement would do for me, and to be frank, apart from adding a lot of weight, not much. I think I'll break it out, line the cup with mica paper and paint the surface with a thinned mixture of cement, the other option is to paint the thinned mixture directly onto the cup, and line the secondary shell with mica, I've noticed the mica paper seems to work better if there is an air gap.

Shrug its all good fun, if I can get the weight down of the cup and still get the 4 min boil on 0.5L of water I'll be happy.

 

[Teepee]

Sounds like a good plan for brushing on, I never tried it on my stove.

The sole purpose for me to initially use the fire cement was to stop corrosion, I'm not sure it helps the burn time though-it probably adds thermal mass and not much insulation. I used Gun Gum at first, but it disintegrates really quickly.

Tsk, with a kayak you should be looking at the sea lochs, if not the west coast itself, but whatever you decide enjoy mate.

The sea lochs and skye are the next trips, but I am proper wobbly noob, I'd capsize at the first sign of a wave. It took me 10 goes at the weekend just to get in the flipping thing, let alone eskimo roll!

 

[Gailainne]

I tried the fire cup with the mica paper, not very successfully, so I tried it with a thin coat of cement brushed on, and that worked better, it lets a lot of heat thru to the outer shell, but I was getting 0.5l of tap water to the boil in around 3:20-25, which I'm quite happy with. Perhaps try adding a layer of mica paper to the outside for insulation. Oh I added a disc of mica paper to the bottom to seal it. I just need to sort out a pot support and wind shield.

I've been wondering if I can swap out the outer shell for that thin titanium that I have, it wouldn't lighten it by much, but the thinness would allow me to fit the mica paper to the inside of the shell rather than the outside.