"Catherine", a USA "Sweet Pea" engine build

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Benjamin Maggi
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"Catherine", a USA "Sweet Pea" engine build

Post by Benjamin Maggi »

This is a brief build log for my still-under-construction "Sweet Pea" steam locomotive. Designed by Jack Buckler in the late 1970s to run on 5" gauge track, it had proved so popular that it was soon converted to run on 3.5" track (known as "Sweet Violet") and 7.25" gauge track (known as "Sweet William"); a different take which visually looks like an 0-6-0 standard gauge tank engine has also been done (known as "Metre Maid"). For some reason, calling an engine "Sweet William" seems ackward so I may lapse and call it a "Sweet Pea" now and then.

During the winter of 2011 I was faced with a set of difficult choices. I had the flame cut frames for an Allen mogul waiting to begin work on, and a complete assembled Locoparts tender kit already finished which I had done in 2009, but no machine shop. I live in a small apartment, and whatever free space I have is devoted more to storage shelves then shop equipment. All machine work I had accomplished to date had been done at friends' houses- an arrangement which was somewhat inconvenient and certainly not conducive to the construction of a steam locomotive.

Also, while I really liked the appearance of the Allen mogul engine I wanted something that would be a bit more different, or unique. I have a passion for British steam engines, and narrow gauge ones in particular, and tried to feed that appetite by scratch-building some 16mm rolling stock to run on the local live steam club's outside Gauge-1 track. Still, it wasn't enough.

There is something to be said for narrow gauge trains running on 7.25" track. Actually, there is a lot to be said! Narrow gauge engines usually are simpler in design then standard gauge models, have fewer parts which are larger, and in many cases are smaller in length (if not larger in width and height). One winter while going through the live steam club's library, I came across the book by Jack Buckler and read it cover to cover. Several times, in fact, over that winter.

A nice discussion on this forum helped give me more information about the engine: http://www.chaski.org/homemachinist/vie ... =8&t=90228

By the next spring I was intrigued enough to order the full plans, which at only 7 sheets total was quite affordable. After some thoughtful discussions with my wife, in which she questioned me ("Honey, everyone else at the club has a steam engine; when will yours be finished?") I decided to take the plunge and begin construction of my own steam engine.

There were several critical reasons to select this engine as a first attempt. First, the book- though designed for 5" gauge- is similar to those written by Kozo Hiraoka in that it explained not only how to machine the parts but what fixtures and procedures can be done to achieve satisfactory results. This was a big boost. Second, the engine was a proven design with hundreds running about the world. (For an excellent write up in the magazine Live Steam & Outdoor Railroading, see their July/August 2010 issue.) Third, it was based on a British prototype engine which not only appealed to my senses but guaranteed that once completed it would stand out at the American live steam tracks. Fourth, its overall dimensions were such that I would not need to purchase a truck or large minivan to transport it around. And finally, the small number of parts would help keeps costs manageable.

Bagnall, the prototype engine manufacturer, made contractor's engines in standard gauge and almost every possible narrow-gauge configuration. I am planning to build it to represent a 27" prototype as might have been seen on the Welsh Talyllyn Railway, but an eye is cast towards a 36" prototype like the Isle of Man Railway. However, at this point it doesn't make a bit of difference.

My fundamental approach to the hobby is two fold: (1) if you don't have the necessary skills or tools to do something, there is always someone you can ask for help, and (2) if you don't get started NOW, you may never finish your engine! As such, when I started the project I only had one mill file and a hand-held drill. I have since acquired a small drill press and a lathe. Fifty years ago people were reading LBSC's articles and with not much more than I had building working steam locomotives. Who knows what I will have when done, but the most important step is to get started.

For now, it is tentatively named "Catherine" because that is a lady's name that my wife and I both like. Who knows... perhaps someday there may be two Catherines in our house?

Other known Sweet William Engines under construction
- there is another gentleman in New Zealand building a similar engine. (http://www.chaski.org/homemachinist/vie ... 45&t=92038) If you see our two threads, I am sure there will be some cross-posting. While we are approaching it in different ways at times, I think both may prove interesting.

- in Australia: http://modeleng.proboards.com/thread/84 ... ild#page=1

- I am also aware of two engines in the USA. One was owned by forum member "Fred V" though only the chassis was a Sweet William, with a redesigned body. Also, Randy Ross owns one up in Michigan ((http://www.chaski.org/homemachinist/vie ... ss#p283000). If anyone else is aware of any, I would love to hear about it!
Attachments
Sweet pea resized.jpg
A picture of a Sweet William
A picture of a Sweet William
Last edited by Benjamin Maggi on Wed Oct 07, 2015 3:46 pm, edited 9 times in total.
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
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Benjamin Maggi
Posts: 1409
Joined: Wed Apr 25, 2007 10:38 pm
Location: Albany, NY

Re: USA - "Sweet William" build

Post by Benjamin Maggi »

I started by purchasing some hot-rolled steel for the main frames. They are generally the first thing that people work on, serve as a foundation for the rest of the engine, and unfortunately have the potential to wreck an engine from the get-go if they are machined carelessly. I began by taking the plans and having them photocopied, and then took one of the copies and converted all the dimensions to incremental. I didn't want any of the "measure from the end 5 inches, subtract 2 inches, and then go ahead another 1.5 inches" problems that could arise. This, in my mind, left too many areas for mistakes. It took several hours of work, and another couple to check the math, but eventually it was done. This would be extremely helpful if I was going to set it up for digital machining, but that wasn't my intent.

I painted certain areas with blue dye. Nothing makes me feel more like a machinist than using the stuff, though I quickly realized that the frames were huge and would consume a lot of dye, AND due to the mill scale my marks were barely visible. I changed approaches to using a thin-line permanent marker. Since the marks were still easily lost, or perhaps because there were so many, I usually double-checked the mark and then immediately punched the spot. Then, I put a white circle sticker around it to visually make it stand out. I don't know where I got the idea from, but I doubt I invented it. I color-coded the stickers to indicate things like drill size, holes for only one frame, and holes to be tapped.
Attachments
R-6.jpg
Last edited by Benjamin Maggi on Wed Oct 07, 2015 3:48 pm, edited 1 time in total.
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
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Benjamin Maggi
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Location: Albany, NY

Re: USA - "Sweet William" build

Post by Benjamin Maggi »

The frames were bolted together and drilled out, which even at a slow feed and plenty of cutting oil sometimes seemed to tax the drill. As the frames were just over 44” long, it required proper support all along the way. I quickly learned how to drill by plunging and withdrawing to reduce chip size, but not until I had a mess on the bits!
Attachments
R-10.jpg
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
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Benjamin Maggi
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Joined: Wed Apr 25, 2007 10:38 pm
Location: Albany, NY

Re: USA - "Sweet William" build

Post by Benjamin Maggi »

I used a bandsaw and metal jigsaw to cut open the axle areas, and then finished up the machining with a horizontal mill.
Attachments
R-23.jpg
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
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Benjamin Maggi
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Re: USA - "Sweet William" build

Post by Benjamin Maggi »

The horn guides are two pieces per axle box, and started with gunmetal castings. I don't really know what gunmetal is but I ordered them from the castings supplier in Britain. While they worked well, the shipping alone cost almost as much as the parts. Because of this, I will try and source everything I need from American castings or fabricate from stock. These horn guides have proved to be the most annoying part of the project to date. Even though we machined all faces, bolting them onto the frames caused them to somehow bow inward. Thus, the bearing surfaces were not perpendicular to the frames. Re-machining didn't help. Part of it may be that the bolt holes I drilled in them were slightly off, thus when the bolts pulled them tight to the frame it took them out. Also, they had to be rounded over at the top to sit into the rounded frame and this wasn't caught until later on. However, several rounds of clamping, drilling, and filing across both with a large file to bring them into square finally worked. I hope I never need to take them off again!
Attachments
R-32.jpg
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
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Benjamin Maggi
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Joined: Wed Apr 25, 2007 10:38 pm
Location: Albany, NY

Re: USA - "Sweet William" build

Post by Benjamin Maggi »

The frame stretchers were next, which I decided to fabricate as a large strip which would later be machined to dimensions and sawed off into pieces. After laying out with a marker, I proceeded to drill the holes to mount the side angles. Then, the angle was bolted on at the ends and transfer drilled through the stretchers for the remaining holes. Every hole was then de-burred. It was an interesting set-up, as the angle came from the store in 4' pieces and I was too lazy to cut them down to a more manageable size beforehand. Thus, there was a lot of overhang on my tiny drill press.
Attachments
R-41.jpg
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
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Benjamin Maggi
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Re: USA - "Sweet William" build

Post by Benjamin Maggi »

At my friends workshop, the edges of the stretcher were cleaned up in the mill.
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R-43.jpg
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
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Benjamin Maggi
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Re: USA - "Sweet William" build

Post by Benjamin Maggi »

Then the individual stretchers were cut off from the large assembly.
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R-46.jpg
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
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Benjamin Maggi
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Re: USA - "Sweet William" build

Post by Benjamin Maggi »

The burrs were cleaned up on a large belt sander, and the corners of the end stretchers were notched to clear the internal steel angle that would hold the end buffer beams to the sideframes.
Attachments
R-53.jpg
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
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Benjamin Maggi
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Joined: Wed Apr 25, 2007 10:38 pm
Location: Albany, NY

Re: USA - "Sweet William" build

Post by Benjamin Maggi »

It was this then that I realized I had omitted to drill the cylinder mounting holes in the sideframes. Since frame assembly was imminent I didn't have time to run over to my friend's house to use his pillar drill press. Thus, mine was again set up in the workshop (which was actually the kitchen as the floor is smooth linoleum and easily swept and vacuumed) and the frames were set up for drilling. It worked well, though it took a bit of adjustment to find the right soup cans!
Attachments
R-54.jpg
Last edited by Benjamin Maggi on Fri Mar 01, 2013 11:11 am, edited 1 time in total.
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
User avatar
Benjamin Maggi
Posts: 1409
Joined: Wed Apr 25, 2007 10:38 pm
Location: Albany, NY

Re: USA - "Sweet William" build

Post by Benjamin Maggi »

Assembly of the frame was accomplished by securing the two end stretchers in place and using large clamps to secure them from moving. Gentle adjustments with a hammer ensured that lines drawn on the outside of the stretcher mounting angles were visible through the holes drilled in the sideframes.

More clamping and drilling with a hand drill made the set-up permanent. Then, with the two end frames bolted in place the middle ones were slipped in, clamped to prevent shifting, and also drilled. We used a machinist's square to ensure that the end stretchers didn't sit proud of the sideframes.
Attachments
R-55.jpg
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
User avatar
Benjamin Maggi
Posts: 1409
Joined: Wed Apr 25, 2007 10:38 pm
Location: Albany, NY

Re: USA - "Sweet William" build

Post by Benjamin Maggi »

I will take a moment and discuss the hardware I am using. The plans called for riveting the stretchers themselves together, but I didn't want to pound lots of rivets. Small hex hardware is available, but square-headed bolts seemed both prototypical and visually different from the rest. Sourcing them was tough, though the community here helped out (http://www.chaski.org/homemachinist/vie ... lts+headed) After delivery I noticed that they were somewhat soft metal and easily deformed by over-tightening. And, my typical wrenches didn't work well on the heads without slipping. But, some time with the Dremel tool turned the wrenches into "square" wrenches and all is well. Some nail polish on the ends help me quickly grab the size I need, as the square bolt heads are different sizes from the square nuts.
Attachments
R-65.jpg
Last edited by Benjamin Maggi on Fri Mar 01, 2013 11:14 am, edited 1 time in total.
"One cannot learn to swim without getting his feet wet." - Benjamin Maggi
- Building: 7.25" gauge "Sweet Pea" named "Catherine"
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