I am sorry this discussion died w/o coming to fruition or any resolution except for the fact it is a rather tall order.
The only reason I registered was to answer question 1) with resounding affirmation. It would be immensely practical and useful to have a reliable device like this. Profitable in economic terms too to have a the highest efficiency stove burning on the cheap feed CONTINUOUSLY AND W/O WORRY. If you can make it you have a deal.
As for question 2) I have no experience with a "J" tube or any other design rocket stove whatsoever. And I do not even intent to acquire any and build my own rocket stove unless the automatic feed question is resolved. I want a practical solution and not a hobby project. Even entry level regular pellet stove now has automatic feed, auto ignition, double or triple burn claiming over 90 efficiency and can be fitted with a heat exchanger for maximum efficiency. Of course it has room temperature thermostatic control - no need to have it on your heated air feed and pay for oil to regulate. The electronics is becoming darn cheap and, unless you demand a lot of control over parameters, completely satisfactory. This is what entry level pellet stove starts to look today: optimized with cheap mass produced electronics.
A rotating magazine with multiple compartments containing one more feed of wood, moved into position only after being triggered by one single parameter (arm-length mechanical wind up sensor). A very clever mechanical device to read more parameters and "make local mechanical computation" to determine action. Complex one computed over temperature and position and alarm multiple sensors reading would be another way to go. That means mastering Arduino elementary programming or re-purposing "smart home" technology. Even hacking control elements of a regular pellet stove and re-using it to control (trigger the feed) of this rotating log feed magazine rocket stove could work in speculation.(get a scrap one?) I would start with very simple design and add complexity only if necessary. I would buy multiple CO alarms and check them regularly that they are operational. I would make sure the default position of the feed magazine is NOT feeding - so no danger would result from jamming. A safety feature would force said default position - by some burn/through fuse that would activate warning/dead man switch safety mechanism. This could be as simple as extinguishing the fire by choking it off.
...sorry...this makes it design # 2, packed with electronics....too complex to be practical and unless you really enjoy challenge, want to learn new set of skills and have a lot of time, this is not a way to go.
...So this is why this thread died off long ago.
Have there been any successes along the way? I am very curious.
Is anyone interested in a rocket stove with an automatic mechanical feed?
- joe
Yes, it's called a pellet stove. I've finished a prototype that can batch-burn cordwood or feed pellets contiuously by gravity feed. I don't know how to post a link to it on this newfangled phone thing, I'll do that when I get back to an old fashioned computer. Meanwhile look for my project build on this forum "Pellets Or Wood".
I'm starting to build the final version indoors.
Anyone who says I am on a fool's errand is probably right.
Even entry level regular pellet stove now has automatic feed, auto ignition, double or triple burn claiming over 90 efficiency and can be fitted with a heat exchanger for maximum efficiency.
That "90% efficiency" is only combustion efficiency... Not that 90% of the heat in your fuel actually stays in the structure.
I am trying to make something that works more or less like a conventional furnace - not something that operates in batch mode, or that requires constant attention. I am interested in the rocket design because of the efficiency.
I am more interested in a 4 inch or 6 inch stove that is constantly running at an even pace, than a larger stove that is fired intermittently. I think that a rocket stove with an automatic feed would be the ideal stove.
By automatic feed, I am thinking of a design where the feed is mechanically assisted. I am not talking about cramming 8 hours worth of logs in a magazine and hoping they feed themselves without getting jammed. This type of approach will not work with real logs, which are not perfectly round or smooth.
The mechanical feed does not need to be electrically powered, but it does have to actually move the logs into position and load them one at a time into the burner. It would be powered by a wind-up type of mechanism.
Is anyone interested in a rocket stove with an automatic mechanical feed?
1 I think I would want one of these if it could work really, really dependably.
2 my 6" stove--it burns big-ish split logs, a bit larger than kindling. I haven't tried putting whole logs into it.
My two cents: I would go the chute idea, at a very shallow angle to prevent a back-chimney effect. I am thinking a grandfather clock pendulum shaking the wood ever-so-slightly to push it along and keep it moving toward the bottom of the chute, or just shaking the whole chute back and forth ever-so-slightly. The grandfather clock would keep moving for 24 hours. (Important that it not be shaking the heater/stove, since consistently shaking cob is probably the best way to crack it, even better than moisture, abrupt changes of temperature, people sitting on it, etc.)
I am thinking there should be two chutes so there's a backup if something fails...but also the problem of this is potential traffic jams.
I am thinking that in any case there should be a smoke detector to let you know SOON if something has gone wrong...and it is only to be operated while at home and you're not farther away than the other room, able to drop everything and get to it in under a minute.
The idea would be that the surest failure point is that it backs up and doesn't feed in more wood and your fire goes out. A distant second would be you get a bit of smoke-back and the alarm goes off.
The chute could be made from metal grating with plenty of airspace; maybe even hardware cloth with metal cables holding it up from the ceiling.
A more complex thing that "feels" when the log is gone and it's time for the next log would be possible too mechanically, in my opinion. I've seen similar things done with the kinetic sculptures (at Boston's Logan Airport, the Science Museum, and in NYC in Penn Station I think).
In frame 1 the log XXXXXXXXXXXXX is on its holder _______________. It is being held up from rotating (gravity would turn it clockwise if it could, with a rope and weight around a pulley) by the log (X X X) that is currently standing upright in the woodfeed (| | | | | | | | | |)
in frame 2, the log under it has burnt down and isn't stopping the rotation anymore. So now, "feeling" that there's a need for another log, the rotating thing rotates from its gravity-pulled pulleyed weight, and the log holder catches on "q", a little hook suspended from a cable. (It would have looked a lot clearer if the font had that letter q hook sticking way out to the right to trip the log holder on it.) The hook tips the log-holder over (clockwise, also), and the log is spilled into the feed.
Some metal and airspace spacing is needed between the bottoms of the log holders for when it's "on deck" and the upright, burning log that's "up to bat" in the firebox. That can be as crude as a rolled up piece of hardware cloth pinned in place by one of Stephen Colbert's Meanwhile monologues.
this is about 10% experience and 90% theory, but I'd love to see it tried!!
"Folks, you know I spend hours digging for aggregate in the high deserts off the coast of the Sea of Tranquility, making test bricks with the Oregon method, carefully testing the burn chamber temperatures and CO outputs, then molding the exterior of the masonry-quality Tesla Roadster Effect-caliber 20x effiency, Erica-Ernie-Paul-and-Peter-approved Rocket Mass Heater that is my monologue but sometimes, sometimes, I like to gather up some toxic gick from the dump, slap it on an empty steel can of aerosol, layer it with Portland cement leftover from a uranium dumping ground, and light it up under a tank of pressurized water for the squish-boom, flaming-heap-of-death segment of news I call--"
deadstarsstillburn: moreover, the house has 3 storeys (large attic) so I assume if I get very efficient heating on the ground floor, that will go a long way toward heating the upstairs as well, no?
Oct 21, 2020 6:53:59 GMT -8
BenAlexanderT: Happy new year everybody. I wish you the best
Dec 31, 2020 15:06:14 GMT -8
Solomon: Anybody in Southern Oregon, in Jackson or Josephine counties?
Jan 16, 2021 21:54:43 GMT -8
gnomedome: i realsie this is from 2009
Apr 14, 2021 8:30:44 GMT -8
gnomedome: i realize this is from 2009 id love to see the photos from this ..as im looking to build a sauna soon similar to this .... if anyody sees this post obomartin@gmail.com..... the photos in this post did not show up
Apr 14, 2021 8:32:00 GMT -8
dcoyte: I am planning to use a cast iron heat exchanger out of a hydronic boiler set on top of my rocket stove, flue out the top. There will be a pump moving the water through the heat exchanger into an unpressurized 2000 gal tank. Any thoughts?
Dec 31, 2021 6:45:55 GMT -8
syekoms: Yes just found this forum am in Josephine county.
Jun 17, 2022 12:53:32 GMT -8
ecoenergyman: Hi new to forum I was wondering where to buy a masonry stove kit I could install myself ? Fran in ireland
Aug 1, 2022 17:39:58 GMT -8
natureman: I have been following this site for years
Aug 28, 2022 10:58:59 GMT -8
nendo: Can anyone on this forum point me in the direction of detailed plans for a rocket water heater please?
Oct 22, 2022 15:15:43 GMT -8
fierolepou: Hi everybody! Starting a project from scratch, this is a goldmine!
Dec 10, 2022 5:20:09 GMT -8
Solomon: Best way to not die in a house fire is to build a stove where the really hot stuff isn't near the flammable stuff.
Jan 10, 2023 11:34:39 GMT -8
beppe: Hi to everybpdy. I'm new about the rocket stoves and this forum
Aug 30, 2023 22:17:32 GMT -8
beppe: I have a living room+ kitchen of 75 square meters that was heated by an ordinary pellet stove with a power of 8KW.
Aug 30, 2023 22:19:29 GMT -8
beppe: I want to switch to a DIY pellet rocket stove but I haven't found yet a project that is really suitable for my situation. Is there anybody able to indicate to me a good detailed project?
Sept 4, 2023 9:05:15 GMT -8
sksshel: Yes, very happy with my DSR2. I had not heard about the DSR3. I probably won't be using it but I will look into it.
Oct 16, 2023 9:15:37 GMT -8
rockinon: I have some questions about a Rocket Mass Heater, as I am in progress of getting a place built in Arkansas in the mountains of NW Arkansas and it will be very helpful. How can I add pictures to illustrate what I am requesting
Jan 23, 2024 11:01:07 GMT -8
dd24: Bonjour, Quelqu'un expérimente t-il sur les poêles "bubafonya" ou "stopuva"? merci pour votre réponse!
Mar 2, 2024 10:32:32 GMT -8