Off-Grider Generator Kit

Not my photos, but a Dake-powered lift truck, a Dake windlass, a Dake winch, Dake chain hoist, and a Dake ship steering engine.

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I am pretty far along with the patterns for a grand-scale Dake.

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Some of the passages that would need to be cored.
Not really a problem if you are good at making cores.
I would use resin-bound cores, since they are very strong and durable with iron pours.

The 3D printed patterns in most cases can also be used as a corebox to make the cores, with some slight modifications to add the coreprints.

As I recall, I have a motion study of this in Solidworks; I will look for a video of that.

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This is Docsteader's motion study for the Dake.

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Interesting! GT: do you sell plans? - When you have completed these plans I think I am interested in buying a set for making a model of this one. The rotary valve is the key I guess? - for port timing. Until I saw the motion, I had imagined some sort of "square" motion of a square piston inside a larger square chamber, with some sort of sliding seals and the steam admission /exhaust sequential from chambers 1 to 4 around the square. But it is simpler, with the square piston simply running from side to side timed by a square valve on the crank running at 90 degrees inside the power piston? - I think?
A bit of precision machining required here!
FUN!
K2

Looks like I have visited the Dake engine earlier.
I forget what I have and have not posted, so some duplication.

I don't sell plans; I post them here for free.
See posts #5 and #6 for drawings for the Dake I designed, which is as close as I could get to a real Dake engine.

https://www.homemodelenginemachinist.com/threads/dake-engine-by-pat-j.34331/

I made these drawings before I got into foundry work, and so the intent was barstock construction.
And this was before I got into 3D modeling, so the isometrics were generated manually in 2D CAD, and are rough approximations.

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Steam and exhaust are routed down the crankcase cover, with one side going to the round ring, and the other side going to the hole, both in the crankcase cover.

The inner piston doubles as both a piston, and a slide valve.
Since this is a two-cylinder engine (two flat pistons; one inside the other), there are no dead centers.
And since the reciprocating mass is very low, the engine reverses very quickly; not quite instantly, but very fast.

The ports in the face of the inner piston (for fulll sized Dake engines) vary in shape, depending on whether the engine will be used as a reversing engine, or just run forward only.

The passages in the inner piston distribute the steam and/or exhaust.
It is truly an engenious arrangement, and it really works well.

For a reversing engine, the round ring and center hole in the crankcase cover can be for either steam or exhaust.

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A few illustrations from a writeup I did about the Dake a few years ago.

The inner piston moves vertically only, and the outer piston moves horizontally only.

I have to guess that Roots originally conceived the idea for this engine by being aware of some of the balanced flat, thin slide valves of the day, where the top of the flat valve was against the steam chest cover.
This would have given Roots the idea of the sliding flat rectangle in a chamber.
How he conceived a piston within a piston, I don't know.
And the porting and passages are really genius.

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I started to make a Dake from my drawings in 2009, but I had just started machining, and so just as I was about to finish the inner piston, I damaged it, and then damaged a second one.
I had better luck with the crankcase exterior, and actually successfully made one of those.

Hogging parts out of solid metal for build attempts like this are what convinced me that I needed to build a foundry and cast the parts for an engine, since all the rough cutting was very tough on my inexpensive Grizzly equipment.

The bottom of the crankcase is actually sloped; that is not a machining error.
There is a sliding wedge that rides on that slope, and that is how the clearance for the outer piston is adjusted.

This build attempt, and a few others, cured me of barstock construction forever.
I thought to myself "there has got to be a better way to build an engine", and that way was to cast the parts.

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The Dake reversing valve is almost identical to the Westinghouse brake valve commonly used on steam locomotives.

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WisJim said:

Regarding using wood pellets to fire a boiler, I have a friend who has been working on a wood gasification unit to run a small internal combustion engine (using a common lawn mower type of engine) and is using an Arduino computer to control some of the functions to make the pellet feed more automatic. I would guess that some of this technology could be used to fire a boiler. I am picturing the kind of pellets used for home heating stoves etc., which are small, uniform, and quite commonly available around me.
I don't know details of his mechanisms.

Click to expand...

Those are the kind I was thinking of. Good luck to him. Those pellets seem like an under utilized resource. I successfully ran them in a mini coupoula furnace with reasonable success. Building a fire box to run on them would be interesting.

Many ex-coal fired power stations in the UK are now burning wood pellets - imported from USA and Canada I think? But I understand efficiency and output are much lower than for burning coal, but fossil fuel consumption is minimised!
Something I haven't yet figured in my head about all this... but I think it goes like this?
Sunlight (energy) and CO2 from the atmosphere with the addition of water (H2O) become Hydrocarbons = wood + released O2. If we can grow enough, and burn these hydrocarbons as fuel we release the CO2 and H2O back to the atmosphere using some O2 from the atmosphere, and get to use the energy where and how we want it... = Equilibrium?
Or the wood can be compressed and heated over millenia and make oil and coal fossil fuels.... which when burned release the energy for us to use, and return the "ancient" CO2 and H2O back to the atmosphere. making it just a matter of time relating to the presence and quantity of CO2 in the atmosphere. SO does that mean the ancient atmosphere had more CO2 and less free O2 than today? And by burning fossil fuels we are simply releasing the extra energy (heat) from those ancient millennia's sunlight? = So we won't kill the planet, just return it to times before humans existed and when jungles were far more common than today?
I reckon it is as much political as scientific... all about money?
K2

Maybe many cannot remember that UK and European locos ran on coal in the 19th century, but the "Casey Jones" locos used wood, as the great plains of the USA were without coal but folk could use wood from trees? The fireboxes and grates were proportionately larger, to get adequate power from the wood fire, and flues a bit larger, and needed regular cleaning because of resins from the wood condensing and capturing ash and blocking the flues, but with good design there were many locos powered by wood logs across the USA. SO wood can make a good fuel with a correctly designed boiler.
N.B. The most successful Gas- and Oil-fired boilers are also "different internal sizes" to coal fired boilers. Each boiler should be optimised for 1 fuel, and will not be as good with different fuel. So a pelletised wood boiler will have too much grate for coal, and wrongly sized firebox and flues for running later on coal or liquid fuels for the same efficiency. Wood fired boilers are not simple kettles on a pile of burning wood, but need careful design as a wood burner first, to generate adequate heat efficiently, then have "appropriate firebox and flues" added to that "burner design". e.g. wood stick "Jet" burners draw a lot of air through the fire to enable good combustion and a large "flame space" to complete combustion so could be adapted to a firebox for a boiler.
This sort of size of firebox (Grate, flue size, combustion space etc.) is needed for 20kW of wood combustion.
https://www.modernstoves.co.uk/prod...kw-back-boiler-wood-burning-multi-fuel-stove/
What power are you considering? At best I reckon this could make 15kW of steam, and then that could make a few kW of useful electricity? - Depending on the engine and generator, water pumps, automating fuel deliver system motors and controls, etc.
An interesting project.
Not a model, but a real job!
K2

Re post#89.
I really understand where you are coming from Green Twin. But I am tempted by this engine as a challenge to my skills as a machinist. It is the occupation of developing a good accurate set-up and then machining it right, that attracts me to the hobby, so I don't just use machining etc. as a means to and end, it is the pleasure of the hobby. Just like a game of football isn't just about the win points and table position at the end of the season, but about the hours of entertainment watching and enjoying the skills on display. Driving a car is about reaching the destination for me, but riding a motorcycle or sailing a yacht is about the journey, even with no destination in mind. - Just like making models - for me. And I think you are hooked on the journey/process of designing patterns, making moulds, pouring metal and machining the castings, etc. to make your excellent models. - Much better for the soul than buying a working model!
K2

Hi WisJim et al.
I have found this article on combustion of biomass. Basically vegetable dust. - from looking at particle size in the texts.
https://etd.lib.metu.edu.tr/upload/12623853/index.pdf
It suggests the volatiles burn very quickly - 2 seconds of a 21-second particle burning- but the "solids" char much slower, the remaining 19seconds.
How that relates to a wood chip burner I have no idea, except the smoke /ash/combustion particles coming off the "mass" of pellets burning will need 20 seconds of transit time in the combustion chamber before passing into flues for heat transfer to water in the boiler. 20 seconds sounds like a long wide flame passage... or maybe large enough flues so the combustion continues along the flues. - I.E. bigger than 1inch diameter? I have no idea how big such a boiler would be for the off grid generation planned, but maybe an inch or 2 bore of flue is not an issue? - And it also depends on exhaust gas volume and speed through the flues....
Hope there is something of use in this?
K2

Steamchick said:

Re post#89.
I really understand where you are coming from Green Twin. But I am tempted by this engine as a challenge to my skills as a machinist. It is the occupation of developing a good accurate set-up and then machining it right, that attracts me to the hobby, so I don't just use machining etc. as a means to and end, it is the pleasure of the hobby. Just like a game of football isn't just about the win points and table position at the end of the season, but about the hours of entertainment watching and enjoying the skills on display. Driving a car is about reaching the destination for me, but riding a motorcycle or sailing a yacht is about the journey, even with no destination in mind. - Just like making models - for me. And I think you are hooked on the journey/process of designing patterns, making moulds, pouring metal and machining the castings, etc. to make your excellent models. - Much better for the soul than buying a working model!
K2

Click to expand...

A good machinist could easily build a Dake engine, but when I started in earnest trying to build model engines in 2009, I basically had to start from scratch as far as doing any accurate machining, and I made a lot of mistakes early on.

Perhaps had I known how to machine in 2009, I may have stayed with bar stock builds, but castings are much quicker to machine, since they only require a light skimming of the mating surfaces.

And my equipment is what I consider low grade (lathe/mill), and while it gets the job done, it is not designed for heavy cutting, and not built like an industrial machine (not heavy duty).
The folks with the good mills especially have it much easier.
I have a buddy who has a really solid horizontal mill, and I have seen quite a few with vertical Bridgeports.

Quality machine tools are not in the cards for me, so I make castings, and that allows me to get away with some lightweight equipment.

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I grew up in the city that was called "The Hardwood Capital of the World" for many years, and there is a great deal of timber that grows in the South-East United States. It is sustainable growth, and some very fertile land.
I was reading last year about the wood pellet industry, and apparently a lot of that comes from this area.

They have oil in Texas and Oklahoma, but we have trees, and hardwood is especially valuable, but softwood is also quite valuable for pulp for making paper.

A lot of hardwood goes from this city to asia, or at least it did during the building boom.
Hardwoods from all over the world were cut, sawn, dried, and surfaced in this city, and then shipped back out all over.
I can remember having wood on our lumber yard from Africa, South America, Honduras, etc., and very exotic beautiful wood.
Some of that wood was not sustainable cuts, which is unfortunate.
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Steamchick said:

Many ex-coal fired power stations in the UK are now burning wood pellets - imported from USA and Canada I think? But I understand efficiency and output are much lower than for burning coal, but fossil fuel consumption is minimised!
Something I haven't yet figured in my head about all this... but I think it goes like this?
Sunlight (energy) and CO2 from the atmosphere with the addition of water (H2O) become Hydrocarbons = wood + released O2. If we can grow enough, and burn these hydrocarbons as fuel we release the CO2 and H2O back to the atmosphere using some O2 from the atmosphere, and get to use the energy where and how we want it... = Equilibrium?
Or the wood can be compressed and heated over millenia and make oil and coal fossil fuels.... which when burned release the energy for us to use, and return the "ancient" CO2 and H2O back to the atmosphere. making it just a matter of time relating to the presence and quantity of CO2 in the atmosphere. SO does that mean the ancient atmosphere had more CO2 and less free O2 than today? And by burning fossil fuels we are simply releasing the extra energy (heat) from those ancient millennia's sunlight? = So we won't kill the planet, just return it to times before humans existed and when jungles were far more common than today?
I reckon it is as much political as scientific... all about money?
K2

Click to expand...

You've got it basically correct, however, the amount of CO2 was apparently so high (and other noxious gases apparently) that we would have a diffictult but not impossible time of living like we do now. With the noxious gases gone, it's one thing and with lots of CO2, it's another thing. Alegedly, the CO2 absorbs heat from the sun and traps it in the atmosphere. I believe that it is so. So the more fossils we burn, the more CO2 and even a bit of radioactive particle (neglible, however), and noxious gasses.

All this effect has naturally been accelerating since ICEs were attached to carraiges and soon became cars which multiplied every year. Maybe you remember only a few years ago, China had only cars for importZnt officials, but now China is like any other industrial nation with millions of CO2 spewing vehicles.

Becausse we elect career politicians, some of whom have never held a real job and don't really understand the world in any way, (e.g. Ted Kennedy, US's present prezident, many, lmany others) , they generally have little or no imagination or ability to synthesize new ideas--all they are capable of is to make back-room deals. Back-room deals have one of two qualities: either a compromise, which may or may not be good, or just as likely, some method of stealing tax payer's $$. (Nancy polosi was asked what was in the 9 THOUSAND page tax bill--her alleged answer was "we won't know till we pass it". THAT, for absolute sure is the type of "deal" that is filled with loop holes and special interest pork barrel deals. Hmmmph!

There are many ideas for CO2 reduction and many of them are just out right silly, e.g. pressurize it in steel bottles and put that in caves. There isn't enough available steel containers to do something so silly,howver, it would make some fool very rich in doing so.

Let me say that there is a partial solution in the Pacific and Atlantic Oceans--they are a huge deposit of dissolved CO2 (same as what makes soda pop fizz). In the Pacific there is a huge area where there is little to nothing living. The reason is that there are no nutrients for the plankton to consume, thus no photosynthesis. What plankton need at a minimum is nitrogen type fertilizer (urea and other stuff) and phosphates and bits of other stuff found in the sea floor. Plankton photosynthesis would absorb heat from the sun, reduce CO2, cool the planet, make food for Salmon and all-round be a good thing.

There are always side effects, unknown, so caution shouuld be observed. My proposal is to put an "X" out in the middle of the Pacific about a mile wide and 100 miles long which can easily be observed to it's effects with nutrients and plankton. Observe for six months to 2 years. If the X is cool compared tothe rest of neargby ocean, then obviously it works--proceed to enlarge the process slowly always watching for unintended horrrible consequences.

I doon't know if a similar process could be done in the Atlantic as the Atlatic is much cooler than the Pacific but I suspect it could be done tosome extent. Anybody have any objections? Let's hear it. Also, let's hear some agreement and additional ideas.
Pleeze vote four me fore presidant, Richard Hed.

I am all for doing something, but that "something" has to involve a finite amount of money, something very measurable and valuable must be achieved, and no politicians should get rich in the process.

As we have it now, crisis are politically "manufacturered", politically advertised, and forced upon us at great expense, with no gain, and no purpose.
Lets not get into politics, because that is a very frustrating topic these days any way you look at it, and has reached an unprecedented level of toxicity that we definitely don't want to introduce to a model engine forum.

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