Becoming a Rocket Scientist

So you really want to have a RMH...
To have one you must build it.
Usually by yourself, maybe with a willing group of helpers (RMH Jamboree) or your beer drinking friends... also willing but maybe not the best help...
By the time you have a running  RMH.
You will be,  at the very least an apprentice rocket scientist!

By the end of the first burning season you will be confident  with your ability's.
You will realize that its all really simple and wonder why you were so unsure before!
You will have repairs or changes (upgrades) that you want or need to do.
Having built your RMH. You will dive right in!
It is not so scary as when you first dreamed of having one.
An rmh built by (You) an accomplished builder will use only a clay mortar.
It takes  very little time to partially dismantle  a clay based build.

The next greatest thing in an RMH build is Morgan Super wool ceramic blanket!
The duct tape of cutting edge rocket science!
Commonly known for being used to create a five minute riser.  
Ceramic blanket can also seal just about anything.
From setting your barrel, to sealing odd size holes or size differences in brick work.
It has replaced making large amounts of clay mortar to seal things up.
Plus it has the added benefit of allowing metal to expand and contract.
If you create your build using  clay mortar and ceramic blanket, a partial disassembly can take as little as 15 minutes.

I'm currently  experimenting with different materials to roof batchboxes.  (advanced master rocket science)
Unprotected ceramic board is just too easy to damage. I want a better option.  

I went out to my shop stove this morning and in less than 30 minutes  I had a double barrel popped top batchbox!
A small bucket of clay mortar and a pile of ceramic blanket  all of which will be reused when it goes back together!

Moral of the story.    
Don't overthink building an RMH.
Expect to improve or upgrade, its easy easy if you use the correct materials.
You can be a Rocket Scientist!
It just takes the gumption to dive in and get your hands dirty.
In a few years you will be doing advanced rocket science experimentation.

Before you know it... you are ready to share with the world .
Talking to complete strangers urging them to learn about RMH's , offering help to nearby builds.
Congratulation's you are now a Rocket Scientist!
Certificate and Lab coat  to follow as supply's become available.  

Thomas, I set a challenge!
My home is small,  about 300sq. ft. and built on stumps 600mm off the ground.
Can a small unit be designed for the following?
- main living area 15 x 21 ft, 16 ft ceiling
- bedroom 12 x 14 ft, 12 ft ceiling
I can fit steel columns under the floor
I would like a small footprint.
Does the bell size influence anything?
Could an old LPG tank / cylinder work, 100lb?

Hi John;
Short answer is Yes.
You can have a tiny batchbox in your tiny house.
Question)   In Australia does it really get cold enough to want an RMH?

Bells can be any reasonable size but they must be surrounded by brick /rock if you expect them to hold heat more than a few hours.

Here is a link to a very long but very good thread about a tiny batch build using an existing fireplace.
I think you will find it very informative.
https://permies.com/t/43809/Masonry-stove-diy-build-feasible

Great pep talk Thomas!
It really is much simpler to build an RMH than we often first think.
I find a lot of people research and plan so much at the beginning that they end up chasing their tail and talk themselves out of building one.
The best advice to convince yourself how simple it is to build one is to get yourself some clay bricks and dry stack a simple J tube rocket stove in your backyard.
No barrel, no mass just yet and light it up!
Once the convincing stage is over that it actually works (duh!) then start adding and refining until it is worthy to look at building one in your living/ working space.
At this stage, this is where the permies forums and in house rocket scientists can really assist with your questions and direct you to help achieve your goals.  
But remember it’s best to start simple to really get a good feel of how and why it works before diving into heating water, your floor, cooking your food, and heating your space all at the same time on your first build

Quick hypothetical.

Golf balls travel further because the dimpled surface create whirlpool eddies of air that facilitate air flow velocity. If you were to experiment with a similar type of dimples on your testing RMH, where would you put them?

A great place to start is by checking out the Free Heat movie.  It has a lot of great ideas and is a really great watch.  There are a lot of really cool resources right here on permies - thomas being one of them!

Hey Chris;
The exhaust stack could be worth a try,  dimple a new one up before snapping it into a round.
However, I suspect that the speed and revolutions of a golf ball has a different dynamic than gas flow.

Thomas, thanks for the response.
Bendigo is an inland city and whilst it does not get snow etc, it can get to minus 1 or 2 at night in winter, with days of below 10 deg. C
I am hoping a RMH would save me the trouble of feeding a wood fire 24 hours a day.

John C Daley wrote:Thomas, I set a challenge!
My home is small,  about 300sq. ft. and built on stumps 600mm off the ground.
Can a small unit be designed for the following?
- main living area 15 x 21 ft, 16 ft ceiling
- bedroom 12 x 14 ft, 12 ft ceiling
I can fit steel columns under the floor
I would like a small footprint.
Does the bell size influence anything?
Could an old LPG tank / cylinder work, 100lb?

This thread by Uncle Mud shows the working bits of his cottage rocket.
https://permies.com/t/150536/Uncle-Mud-CottageRocket-Paper

They are very small and compact.

The cottage rocket goes into a 55 gallon barrel. I think a 100 lb propane tank is smaller in diameter, so a J-tube is not quite going to fit completely inside it, but a bump out for the feed tube and end of burn tunnel would be easy and maybe even simpler to build than the "hollowed" barrel of the cottage rocket.

A unit like this will be light enough that any reasonably decent floor structure can hold it with no added structure below. It can have enough mass included in the barrel/tank to hold heat overnight.