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Post by Donkey on Mar 25, 2012 9:22:39 GMT -8
Perhaps I could anneal the piece? Heat to cherry red and bury in ashes till cool.. That would relieve the tension somewhat. Thanks for pointing that out, I should have known it but... I find it interesting that the first time the plate warped, it warped inward and subsequently it's been warping out. Probably changed the tension direction by hitting it repeatedly. ?? Well.. I've begun building the plate out of 1/4 inch stuff. I sourced the material out of a piece of pipe. I think the pipe was used to pump concrete, as there were thin layers of cement in it. I cut the pipe heated it in the forge and pounded it flat.. Today, I planned to bend and grind it into shape. What's funny is that there is probably a lot of tension on this piece now.. Chances are that it would have warped too and I would have been utterly mystified.. Well... I've got some thinking to do. I'll anneal the plate in my shower house and see what happens and maybe I'll make the new plate out of the same stuff (water tank), anneal it too and perhaps use something thicker ONLY if this doesn't work out. This is good, that 1/4 inch stuff is a real bear to work with. Thanks again Peter!
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Post by Donkey on Mar 25, 2012 9:10:35 GMT -8
Hopefully there's not enough smoke down there to act like a real smoker.. If so, you're not getting what rocket stoves are supposed to provide. Still, it WOULD flavor the food. Might be a great way to make jerky. I can see having more than one chamber, each with it's own temperature range.
I really like where this is going!
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Post by Donkey on Mar 25, 2012 9:05:58 GMT -8
Yeah.. You noticed.. I never intended for it to work like that, never thought of it. I only noticed AFTER it was done and burning, sitting on the stove will let you know how it operates. I think that I'll start building RMH benches more like bells in the future, with the pipes at or under floor level (or no pipes at all) and bell chambers along the bench.
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Post by Donkey on Mar 24, 2012 10:48:33 GMT -8
Thanks Peter.. It's raining, and I won't be at the building site for a few days.. It will be a great day (today) to make a Peter-Channel for that stove. The P-channel in my shower house keeps warping and needs to be banged flat every so often.. My plan for this P-Channel is to make it out of some serious thick metal, hopefully to solve the warping issue. I'll post pics when I get to that point.
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Post by Donkey on Mar 24, 2012 10:43:45 GMT -8
I agree.. It's totally worth a look. I'd also be interested to know what would happen if you stuck a burrito (or something) inside your clean-out..
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Post by Donkey on Mar 23, 2012 16:19:57 GMT -8
Huh.. Cool idea! Have you tried sticking a piece of food in the thing yet? I'm thinking that if heat is drawn in there, so will that nuisance light ash. Building a small oven there would stack functions, you'd get a convenient ash clean-out and a cooker/warmer. I think you'll need a good tight door or you'd risk CO poisoning.
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Post by Donkey on Mar 23, 2012 7:06:35 GMT -8
Another question.. Looking at the cast trip wire in your thread, the profile of the tripwire is somewhat concave, like a skate-ramp, it flares. The tripwire I've carved is more wedge-like, straight transition (or close to it) from front to back. Do you think it makes a difference? What kind of profile (do you think) is desirable?
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Post by Donkey on Mar 23, 2012 6:37:50 GMT -8
It's an 8 inch system.
It's why I chose 8 mm. In the small scale development thread, you mentioned 5.5mm for 4 inch stove and 7mm for a six inch stove. I just guessed that it might be scalable and that it would need to be a little larger. If it is better to make it smaller, I will.
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Post by Donkey on Mar 22, 2012 19:53:22 GMT -8
Peter, I'm building another rocket stove powered sauna and I want to incorporate a tripwire (among other things). Today, I made a brick tripwire. It's the second brick in the lineup and it looks like this: The tripwire is (roughly) 8mm deep. I looked over your threads discussing them and made the tripwire pointed (arrow shaped) based on your comment that it works best at an angle to flow. We test fired the stove today, started with the tripwire brick in and after a time, switched to a normal flat brick. There' s no barrel on and the heat riser hasn't been insulated yet, so I didn't expect to see much difference.. I didn't. After taking out the tripwire brick, I did notice a pattern on the brick itself and photographed it. You can clearly see where the hottest places of the fire (touching the brick) are. The stove is covered in wet cob/clay mortar, etc and hardly got up to heat.. I Imagine that after a good long hot fire, the carbon tracks will burn off. Thought you might like to see this before I ask my first questions. Is an 8mm tripwire too big? Is the angled cut a good idea? Am I on the right track?? ??! Thanks.
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Post by Donkey on Mar 22, 2012 19:28:30 GMT -8
If the top of the chimney is out in the clear (above roof line, etc) you could use a rotating chimney cap instead.. They have a vane on them and rotate to face the exhaust out of the wind. They work pretty good.
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Post by Donkey on Mar 22, 2012 7:33:33 GMT -8
Ok.. that might work. You will need to reduce back to system size for the bench. If you keep the pipe larger than system size you may have other troubles. Also, don't see room for an insulated heat riser in your drawing.
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Post by Donkey on Mar 21, 2012 19:09:36 GMT -8
I tend to forget to build the ash drop.. As you've said, it's easier not to. Oops.. I wasn't paying close enough attention.. You have a 7 inch system, 38.48 square inches. your dimensions (5.25X7.25) are 38.06 square inches. Seems like it should be OK. It's a little smaller than system size, you could go a little larger but it should be fine. I wouldn't lengthen the burn tunnel. For the J-tube configuration, especially if you have a run of bench, keep the burn tunnel as short as possible.
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Post by Donkey on Mar 21, 2012 16:09:35 GMT -8
I know, this area is for finishes and finished stoves, but... Here's a picture of the guts. This little thing has tight tolerances inside.. I had to open it up and carve out the cob below the barrel 3 or 4 times to get it right. That and a Peter-Channel and it works great. Attachments:
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Post by Donkey on Mar 21, 2012 15:43:02 GMT -8
Here's a little six incher built into a tiny cob cottage. The space inside is something like 100 square feet. This little guy does fine. Attachments:
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Post by Donkey on Mar 21, 2012 15:36:10 GMT -8
Last fall I built a rocket mass heater for my earthbag home and was thrilled with my initial results. However after a few burns it started experiencing problems. The draw would stop, reverse and rocket backwards!! blowing smoke and fire into the house. Then it would correct itself and start working well again for a bit. This led me to think that there was a pressure change problem somewhere and not a blockage, because the airflow in both directions was pretty strong. So now I've removed the whole thing and am preparing for a rebuild. There was no blockage as I suspected and my problem may have been that which is outlined in the helpful hint thread: donkey32.proboards.com/index.cgi?board=discuss&action=display&thread=337It's pretty likely that will do it.. While you're in there, make sure that your insulation is in good order.Also, you might have an issue out at the end of the chimney. Did you have windy days when the stove was acting up? I remember that in the book, though I don't really know that it's important.. Better to get close on the cross sectional area than anything. Seems like one average fire-brick flat plus one on edge (without mortar joint) is 7 inches (At least the bricks I've been using). It's got me making the things 7X7 more often than not.. Seems that you're probably inside acceptable fudge factor.. Gotta try it and test it before you make it permanent. The little barrel will be too tight to easily build an 8 inch rocket stove in.. Gotta make room for the insulation!
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