World's smallest and lightest fan forced TLUD stove.

[Gailainne]

I had a chance to start on the TLUD this afternoon, its based on the 1L model so it will be bigger, the cup is 74 Dia by 60 tall. I used the datasheet to work out my primary and secondary, 10x 2.38 primary, 14x4.5 secondary which will give me slightly over 5:1.

I tried using the base as the outside and the cup holder, it worked but not after cutting away a lot of metal from the bottom, aren't Dremels wonderful.

Anyway, loose fitted the cup to the base, (after peening over the edge) and added two handfuls of wood pellets, wax and paper to start it, and sat the whole thing on top of my woodgas stove to add a fan source. Worked very well, no blue flames but a nice long burn. Next step the cut out and adding the fan, I need to order a couple of those Sunon fans, I'll use a 12v evercool I have until I get them.

 

[Gailainne]

Top work, Stephen.
I'm really looking forward to seeing the results of the cloning, and I suspect you are right with the teg.

With this stove run time, I think it will be impossible to harvest any meaningful power from the tlud body, but the windscreen is heated immediately by the lighter fluid on start up.

The flat teg could be incorporated easily into the top side of the fan cowling, allowing the cold side to be cooled by the incoming air. The hot side could be contacted by a heat conducting probe that is integral to the windscreen, maybe made from copper, or possibly alu. This could cause problems with hot primary air, so would need the air flow dividing in the fan cowling, this would not be too hard to do and would enable adjustabilty of the air flows too, if the divider was angle adjustable.

I hope this makes sense.

Didn't see this until after I had posted, we think alike, I laid something out in autocad along the same lines;

Basically as you said, TEG let in to the top of the fan duct, small aluminium heat sink added inside the duct for cooling, supported by more mice paper, top section probably copper bar brazed to a thin copper plate. Whole thing covered in fire cement.
Probably have to chop bits off the end inside the firebowl until a compromised is reached.

 

[Teepee]

Nice work, I'm impressed.

I found it easy to make the fan cowling by scoring the alu sheet with a knife against a straight edge, and using the cuts as fold lines-these can be used as bends or flexed until broken off-it gives really quick and neat edges.

Another way of making the cowling is with an aerosol can, or even an alu drinks can , a 50mm can makes a good fit for the fan when bent into a square shape.

 

[Ray Britton]

Teepee.
My apologies...I mis understood what you were referring to in your post. In reality, any stove design can be made smaller, and most can be made much lighter too (but it gets more expensive as you go).

I think the TLUD stoves are very ingenious, but are not for me as they are very fiddly, and most do not burn collected wood very well, so still rely on carrying your own fuel (there use or adaptation as forges is another matter altogether though). The thing that stands out to me as being too big or too heavy (if you are concentrating on small/light only), are things like using very heavy batteries, and then using more than one of them; using heavy steels instead of lighter metals, and even the length of the cabling used. That said, it is easy to make these things smaller and lighter if that is your desire, but that will obviously seriously affect the price per unit, availability of specialised batteries, and functionality of the unit too.

As an example, if you used a 18650 battery with the stove it would be smaller and lighter, plus you would only need one (so would need a smaller/lighter battery adaptor too).....But the obvious drawback to this is the cost and availability of the batteries....For usability, AA's or AAA's win every time!

As for the stove in the video, don't mis-understand my admiration for anyone who can construct something to that level of craftsmanship, and I have to say that the fit of the fan unit to the body of the stove was as good as anything you could buy in a shop as a 'top of range' product

 

[Gailainne]

Nice work, I'm impressed.

I found it easy to make the fan cowling by scoring the alu sheet with a knife against a straight edge, and using the cuts as fold lines-these can be used as bends or flexed until broken off-it gives really quick and neat edges.

Another way of making the cowling is with an aerosol can, or even an alu drinks can , a 50mm can makes a good fit for the fan when bent into a square shape.

Yeah, well laying something out in autocad, with its precision is easy, converting it to the real world is another matter, nice idea with the aluminium, especially the cans, I was going to use the mica sheet, but perhaps aluminium sheet will be more robust, may have a problem with heat transfer tho.

 

[Teepee]

may have a problem with heat transfer tho

.

There is a problem with it. I used it for the strength/weight qualities but its not ideal. The cowling I made from a coke can got crushed in the pack and I wanted something heavier duty.

Ti sheet would be much better

 

[Gailainne]

.

There is a problem with it. I used it for the strength/weight qualities but its not ideal. The cowling I made from a coke can got crushed in the pack and I wanted something heavier duty.

Ti sheet would be much better

Hmm

Not sure about that, Titanium is even worse for heat transfer, I have some from Titanium goat but it is really thin, probably too delicate for this. I've noticed 1664 beer cans are thicker than normal, I also have aluminium sheet which is relatively thin, or I may just use whats left of the vacuum flask.

I've ordered 3 fans from Farnell, you were right £20 min, shrug they will get used. I'm also really interested in the TEGs from the States, I would take 4, if you go ahead with an order, if you work out a ball park price happy to paypal up front.

If you want me to get you a couple of those 0.5L flasks let me know.

 

[Teepee]

Check this link for ti / alu / stainless. Its a proper useful site for any reference.

http://www.engineeringtoolbox.com/thermal-conductivity-metals-d_858.html

Those flasks would be great.

For ease of cutting and messing with for a prototype, the empty 1664 can is a winner-plus you can drink the contents.

I'm on the tegs case as we speak, PM you soon.

 

[Teepee]

http://www.thermonamic.com/TEHP1-1264-0.8.pdf

This is one teg supplier, the other I am having trouble finding again.

 

[Gailainne]

Check this link for ti / alu / stainless. Its a proper useful site for any reference.

http://www.engineeringtoolbox.com/thermal-conductivity-metals-d_858.html

Those flasks would be great.

For ease of cutting and messing with for a prototype, the empty 1664 can is a winner-plus you can drink the contents.

I'm on the tegs case as we speak, PM you soon.

Now that's really interesting, aluminium is far worse than Titanium, I was always under the impression it was the other way around!, it's always a learning day, and never assume.

Nice one.

I'll pop up to town for a 0.5L flask tomorrow, and take some pics, if its the right one, I'll get you a couple or what they have.

 

[Teepee]

Teepee.
My apologies...I mis understood what you were referring to in your post. In reality, any stove design can be made smaller, and most can be made much lighter too (but it gets more expensive as you go).

I think the TLUD stoves are very ingenious, but are not for me as they are very fiddly, and most do not burn collected wood very well, so still rely on carrying your own fuel (there use or adaptation as forges is another matter altogether though). The thing that stands out to me as being too big or too heavy (if you are concentrating on small/light only), are things like using very heavy batteries, and then using more than one of them; using heavy steels instead of lighter metals, and even the length of the cabling used. That said, it is easy to make these things smaller and lighter if that is your desire, but that will obviously seriously affect the price per unit, availability of specialised batteries, and functionality of the unit too.

As an example, if you used a 18650 battery with the stove it would be smaller and lighter, plus you would only need one (so would need a smaller/lighter battery adaptor too).....But the obvious drawback to this is the cost and availability of the batteries....For usability, AA's or AAA's win every time!

As for the stove in the video, don't mis-understand my admiration for anyone who can construct something to that level of craftsmanship, and I have to say that the fit of the fan unit to the body of the stove was as good as anything you could buy in a shop as a 'top of range' product

Thanks for the praise, Ray.
I basically agree with you on all points, the potential drawbacks are many, but I think most of them can be removed.
The most exciting thing about these stoves is the ability to produce constant and free electricity with tegs and solar power, and be able to have a proper fire anywhere.

The battery issue has been solved-the stove runs off my phone battery, or one aaa cell by way of a tiny regulator.

 

[Teepee]

Now that's really interesting, aluminium is far worse than Titanium, I was always under the impression it was the other way around!, it's always a learning day, and never assume.

Nice one.

I'll pop up to town for a 0.5L flask tomorrow, and take some pics, if its the right one, I'll get you a couple or what they have.

Thanks Stephen.
You are dead right on the learning bit-the day I die is the day I stop learning.

 

[Gailainne]

Is this the flask you've been looking for?

If so there's probably a 10-12 sitting on the shelf.

 

[Teepee]

It looks very similar, Stephen.

The one I used had a tiny drinks chamber, probably 100ml, and it wasn't a vacuum either- thats probably why it was in the pound shop.

The cup and bottom cap is likely to be near identical though and at that price, I bet the exterior wall is thin too. It also says 'Thermal', not 'Vacuum', so I suspect its not a vacuum. Does it feel light?

With a 0.5l capacity, the interior may be useful too.

You are my favourite person of the week, top marks.

Is it from a national chain of shops or a local?

 

[Gailainne]

On the label it states it will keep hot liquids hot for up to 8 hrs and cold for up to 24hrs, the construction is as a vacuum flask,there are 2 layers to the sides and 3 at the bottom, (which is why I had a bit of a problem cutting it all out) it actually feels quite robust, similar to a thermos of the same size.

The cap od is 62mm the base od is 68mm, overall height 250mm.

 

[Teepee]

The dims are right, but the guage of the stainless external wall may be thicker.

Anyhow, its the cup and cap that are most important to make the stove. A double thickness external wall should add 10 g or so-not too much.

 

[Gailainne]

Sorry meant to say its from poundstretcher.

Its funny when I made the TLUD from the 1L flask I thought that was tiny, well it is compared to my woodstove, but the 0.5L is another league! its titchy.

I'll probably get another couple, let me know if you want me to add a few for yourself.

 

[Teepee]

Sorry meant to say its from poundstretcher.

Its funny when I made the TLUD from the 1L flask I thought that was tiny, well it is compared to my woodstove, but the 0.5L is another league! its titchy.

I'll probably get another couple, let me know if you want me to add a few for yourself.

When I made mine, I did it really just to see how small I could go, I never really thought it would work properly, let alone be usable. I was shocked when I first put 2oz of wood pellets in it, and nearly fell over when 1 oz of paper pellets boiled my kettle.


Thanks again, Stephen. :You_Rock_



*Gets in van, races to £stretcher * .................."Fill my van with £2.99 flasks!"

 

[Gailainne]

, no worries.

A while back either lidl or aldi had a dremel clone kit of cutting/burnishing wheels, which included a thin cutting disc, with a diamond dust or similar coating, it was awesome for cutting stainless, unfortunately the two I had are worn out so back to the dremel style ones, which are crap, either thin and break far to easily or thick and burn out to quickly

Ah ha, maybe a saviour Rotocraft

 

[Teepee]

Yeah, those discs don't last long.

I have a flexible drive with the same discs mounted(thin ones), that I clamp in the wood vice, and turn the flask section against the spinning wheel.

I went through 3 or 4 discs per cut 'til I found out that if I deep score the entire cut to the point of being paper thin, I can do it with one disc. When the metal is this thin, it easily snaps off with a bit of light flexing and cleans up well with abrasive paper-I hope this saves you some discs, and some time.