The William Harris Steam Donkey Engine in 2.5 inch Scale

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Pipescs
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The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by Pipescs »

Just a quick check to see if anyone has ever built the Harris Steam Donkey Engine in 2.5 inch Scale?
Charlie Pipes
Mid-South Live Steamers


Current Projects:

Scratch Built 3 3/4 scale 0-4-4 Forney
Little Engines American
20 Ton Shay (Castings and Plans Purchased for future)
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Pipescs
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Re: The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by Pipescs »

Hmm, Looks like its time to drag out the Laptop and renew the Solidworks License.
Charlie Pipes
Mid-South Live Steamers


Current Projects:

Scratch Built 3 3/4 scale 0-4-4 Forney
Little Engines American
20 Ton Shay (Castings and Plans Purchased for future)
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Re: The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by Soot n' Cinders »

I’d be interested if you do! I’ve thought about building a 2.5in scale twin drum donkey to go with my shay.
-Tristan

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-2.5" scale Class A 20 Ton Shay

Steam Siphon: https://www.shapeways.com/shops/leavitt ... tive-works
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Steamer Al
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Re: The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by Steamer Al »

I haven't built it myself but it's on my "wish list". I have the plans/build series from Live Steam in 1989, and it looks like a fun build. Of interest to railroaders, Bill Harris also did a one part article in 1991 on turning the donkey into a skidder/loader. Mr. Harris knows how to have fun!

I did build the whistle from the donkey plans! A little over-scale for my boat project but it sounds pretty nice and is easy to build.

Alex

Edit: sorry for the sideways pictures.... they are the right way up on my phone though...
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Berkman
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Re: The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by Berkman »

a worthington duplex water pump would look really neat on your 2-4-4.

Not sure who, if anyone currently makes castings/drawings for them though.
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Pipescs
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Re: The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by Pipescs »

I’d be interested if you do! I’ve thought about building a 2.5in scale twin drum donkey to go with my shay.
Hey Tristan, This is where I am going also. Having played with a friends Shay and the Donkey Engine, I am afraid I have been bitten.

I have started the boiler on the shay but have put off working on the machining until I have the Forney on the track running.

This could be an interesting side project. One other person is interested. I will get a PM off to you if you are interested.
Charlie Pipes
Mid-South Live Steamers


Current Projects:

Scratch Built 3 3/4 scale 0-4-4 Forney
Little Engines American
20 Ton Shay (Castings and Plans Purchased for future)
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Pipescs
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Re: The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by Pipescs »

Thoughts on scaling up.

I should mention this is going to be a evening project on my Laptop of drawing the parts 3D using Mister Harris's Book for guidance. If I get thru this I will offer the drawings to anyone for free, but only after they show that they have purchased one of his books.

Realizing the engine is not a true to scale design I do not think I will pursue a direct scale up of the original drawing.

Things that effect the scale up are the gear set and the cylinders.

The original cylinders were from the Stuart Victoria with a one inch bore and stroke. The next size up is the Stuart No. 4 which has a 1 1/2 inch bore and 1 1/4 inch stroke. I can order the cylinders, steam chest and steam chest castings directly from Stuart. This effect the flywheel size and a few of the engine dimensions . Nothing dramatic


The gears were Boston NA 90 with a pitch diameter of 4.5 and 1.1 inches. These are still available commercially but are also available out to larger sizes. As they are not available to a true 2.5 inch scale up it will require moving the placement of the drum shafts to accommodate the change in diameter.

To redraw the original drawings into 2.5 inch scale would require a factor of 1.6666666667. This will cause a lot of frustration when trying to work with stock sizes. Fender recommended a simple scale of 2 times the original drawings to make it a 3 inch engine. I am leaning to a factor of 1.5 inches which will produce a engine a little smaller than 2.5 but still be compatible with the 20 ton Shay by John Buckwalter. It also works well with the cylinders and the gears.

More Later.
Charlie Pipes
Mid-South Live Steamers


Current Projects:

Scratch Built 3 3/4 scale 0-4-4 Forney
Little Engines American
20 Ton Shay (Castings and Plans Purchased for future)
Soot n' Cinders
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Re: The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by Soot n' Cinders »

Pipescs wrote: Sun Nov 21, 2021 9:24 pm
I’d be interested if you do! I’ve thought about building a 2.5in scale twin drum donkey to go with my shay.
Hey Tristan, This is where I am going also. Having played with a friends Shay and the Donkey Engine, I am afraid I have been bitten.

I have started the boiler on the shay but have put off working on the machining until I have the Forney on the track running.

This could be an interesting side project. One other person is interested. I will get a PM off to you if you are interested.
I am interested!
I agree with Fenders 2X multiplication too. That would give a 2in bore cylinder which would be 10in roughly full size. 10x12 seems to be a pretty common size for donkey engines from what I’ve seen. Would be a bigger donkey but I think it would still look good with the Buckwalter shay, 20ton was a small locomotive.
-Tristan

Projects
-2.5" scale Class A 20 Ton Shay

Steam Siphon: https://www.shapeways.com/shops/leavitt ... tive-works
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NP317
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Re: The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by NP317 »

Pipescs said:
"To redraw the original drawings into 2.5 inch scale would require a factor of 1.6666666667."
That's a devil of a scale... :roll:
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Pipescs
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Re: The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by Pipescs »

Evening all,

Quite a bit of interesting conversation with modelers with all sorts of input.

Primary change was to convince me to draw the design in 3 inch scale instead of 2.5. This does make the math easier but at the same time has some major impacts.

Primary is that the Harris engine is built on readily available cylinder castings and commercial gears.

Stuart can provide a pair of cylinders kits but you are looking at around $800.00 for two sets. Drawings would have to be modified to suit the new cylinder. A set of Buckwalter Shay cylinders were recommended, and would work, but I am not sure these are available at this time.

Gears from Boston while going up to 9 inches on the diametric pitch jump up into the $600 dollar range. Also the gears are not available in an exact match and the frame drawings will be impacted again. There is the option to machine these from Cast Iron disc. This turned out to be an expensive route also. An idea to have me turn out patterns and have the gear, clutch backplate and brake disc cast in iron also was suggested. This is actually doable as the patterns would be quick to produce and the cost of the castings would be fairly inexpensive at Cattail. My large 8 inch wheel castings were under $15.00 a few years back.

This and other things make this into a new project. Not simply blowing up Mr. Harris's design.

All this said I am setting down to the table to work on a workable frame to support the two steam engines. Logic being to layout and draw the frame using stock sizes that are commercially available, then go to the steam plants and cross shaft.

Last question of the night. Does anyone have contact info on William Harris?
Charlie Pipes
Mid-South Live Steamers


Current Projects:

Scratch Built 3 3/4 scale 0-4-4 Forney
Little Engines American
20 Ton Shay (Castings and Plans Purchased for future)
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Pipescs
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Re: The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by Pipescs »

And so, it begins. I spend the days in the shop; working on the Forney, and work on this at night while sitting with my wife, who is watching Christmas Movies.

I started on the frame rails tonight, I Found Aluminum channel on line with specs of 3x1.5xx.258 at 55.00 for four feet. This matches the Harris Plans.

I am working thru the frame first as drawn in the book and will only modify it if I cannot find a material that is available or has to be changed when it comes to the gears or cylinders.

The nice thing about CAD such as Solidworks is that you can virtually build the assemblies and test things as gear mesh and rotation before you cut metal

F2 Base Channel (Right Hand Side).JPG
Charlie Pipes
Mid-South Live Steamers


Current Projects:

Scratch Built 3 3/4 scale 0-4-4 Forney
Little Engines American
20 Ton Shay (Castings and Plans Purchased for future)
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Harold_V
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Re: The William Harris Steam Donkey Engine in 2.5 inch Scale

Post by Harold_V »

Charlie,
Interesting project, one with which I wish you great success.
I do have one question.
Why aluminum? Steel would most likely be far cheaper, and most likely better.
I'm not critical of your choice, just curious.

H
Wise people talk because they have something to say. Fools talk because they have to say something.
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