Large Scale Central

Steam powered furnace blower

So this topic was started in the general category as a prototype discussion.

But I figured it was better moved here for my actual build. So the 3D model is made. The files are supported and sliced. The first of the print just came off the printer and are in final curing.


Here is the 3D model.

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I should have mentioned this in the beginning. Since I had no real world measurements I based the 1:1 size of this based on counting bricks and using a standard brick dimension. I then made this particular build a 1:20.3 version as I wanted it a bit larger than my normal 1:24. Where its gonna sit I think it will look better a little larger.

did you forget the connecting rods between teh wheels and the bel crank type arm?? not that i know a thing about these, just looks like something is missing

I didn’t forget them, I just hadn’t drawn them yet when that picture was produced. I have them now.

Just to confuse things . . . All bricks are not created equal. Especially old bricks.
We visited Fort Delaware, which is a great big red brick fort on an island in the middle of the Delaware River. On the roof/ramparts are stacks of bricks, bought to use as parts of the Fort are repaired/renovated. They are the wrong size and can’t be used.

That being said, they aren’t that much different in size!

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When I did this I didn’t know what size a “standard” brick was. So I had to look it up thinking since bricks are ancient that a brick standard must have been established fairly early on. At least by the mid 1800’s. nope. And even today while most bricks are standard like many things there are those that fall outside the standard. But like you said there are not enough of a size difference to really make a difference. I am not making a rivet counters replica of that furnace blower. In fact I am not making THAT blower at all. Mine is made by Devon’s Steam Engine Co. They used a brick in their construction which was 9 X 4 1/2 X 3 1/2.

That’s my story and I am sticking to it. I googled “old brick sizes” and the first thing that popped up was a article by the Trending District Council and they said that by 1840 a widely adopted size was 9X 4.5X 3.5. This is a British outfit but I figured its close enough for what I am doing certainly and looked about right. So I rolled with it. I made the base the same number of bricks in all dimensions and then just built my way up. Not one dimension on this model is anything more than my guess and artistic license for what looked good to me.

So now that the furnace blower is printing I went to designing the boiler. I do love the Carrick Furnace boiler that operated the furnace blowers steam engine. The dual boiler cylinders/bodies with the adjoining cross piece is a cool design. I have guessed and assumed that two smaller boilers would be easier and faster to heat up than one large one with the same volume. Especially when only heated from the bottom. And I assume further that the cross piece acts as a pressure regulator since you really can’t control heating them exactly evenly and developing the exact same pressure so I am guessing that is what that does.

Anyway here is where I am going with it.

Got to thinking about my presumption about the cross tank on the boiler. I doubt it served as a regulator, though it would do it by default.

That piece has to be more of a steam collector. I had mistaken thought that the lower flanged pipes were the steam supply. But they can’t be because they would be below the water line. So they have to feed water into the boilers. Steam in all boilers is collected from the top. And that cross piece is valved. So being tied to the top middle of both boilers would be collecting the steam and then distributing it to the steam engine.

Well all of the parts for the blower have been printed. Some minor clean up and I can assemble it. I think the size is gonna be perfect. No idea how close to real it is but I think for the space I have for it and its associated boiler and kiln Its what will fit nice.

Here is progress of the 3D model of the boiler.

That pipe will just go into the ground to be attached to some hypothetical water source. I am thinking I might make a little water tower just for fun. But that will remain to be seen. It could be just as easy some off site water source.

Using these two Rooster supplied photos for the design

Great work, Devon.

Just musing, but the steam outlet looks like a diverter valve, move the handle the steam goes one way, otherwise the opposite, probably center is off. Maybe one way was to the air compressor, the other to blowdown?

I don’t see a relief valve of any sort, but maybe this was built before that lesson was learned (the hard way). :grin:

Very cool project!

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The other thing I notice is that these don’t look like a standard boiler. There’s no tubes, for one. And there’s what looks like a large rod and bolts going through the center to hold the ends on?

Good catch. The actual boilers have end heads with inverted riveted flanges.

But the steam chamber above them has removable end plates, secured by that central through-rod and nut-bridges (not sure what the term is) at the ends .

Behind that thick removable plate will be the annular flange / angle which is riveted to the outer cylinder.

I’m half tempted to go measure Carrick for Devon. However the brick theory does work as I measured LEMO tower by a brick and a year later went down to Strasburg and measured it with a tape only to find out I was spot on by a few inches.

LEMO? Is that a thing, or a mis-type of LEGO?
But yeah, go measure it for the Dev! And maybe take pics of the rear ends, and other ports maybe?

Lemo is a thing…

Thanks all. I believe you are right Cliff about it being a diverter. That top on the cross cylinder has a flange on each side of it. So would make perfect sense and would further give me understanding of how it would work.


I doubt very seriously that it would have tubes in it. Boilers like we are used to have fire at one end and the hot gas is put through the tubes and released at the other end. So the tubes are necessary to get the fire in contact with all the water in the boiler. Faster more even heat.

But on this thing the way the fire is kinda built under the things i don’t think any smoke or fire is moving through them. I think it just sits on it like a kettle. And two small diameter boilers would heat up faster than one large one doing that.


I would never ask for a special trip. But if you do head near there it would be cool to get a feel for the real size of it.

I’m sure I will head out that way again sometime this year just not sure when. It’s technically only an hour from me heading out the PA turnpike. However it will be an all day trip as I have to take the long way up over mountain on the jeep trails and hit 3 different scenic overlooks, Brunt Cabins Grist Mill and then if I have time (which I probably won’t) the EBT RR is about another 45 minutes to and hour north of Carrick. However when I do I will get measurements!

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Sounds fun. And at this point measuring it would just be anecdotal information. Nice to have.