12" working railroad

Discuss park gauge trains and large scale miniature railways having track gauges from 8" to 24" gauge and designed at scales of 2" to the foot or greater - whether modeled for personal use, or purpose built for amusement park operation or private railroading.

Moderators: Glenn Brooks, Harold_V

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Topics may include: antique park gauge train restoration, preservation, and history; building new grand scale equipment from scratch; large scale miniature railway construction, maintenance, and safe operation; fallen flags; track, gauge, and equipment standards; grand scale vendor offerings; and, compiling an on-line motive power roster.
rkcarguy
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Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Fri Aug 25, 2017 11:43 pm

I had some good progress tonight, more than expected. Instead of using the skill saw, I bought a straight 3/8" bit for the router and made a quick fixture on top of a sawhorse. It was just a block of 2x8 I shaved down to 6-7/16" wide which yielded me 12-1/16" gage with the router base added. Then I screwed to a piece of 2x4 onto it at a 90* angle, which was then screwed to the top of the sawhorse. Work had an equipment crate that was all busted apart and destined for the trash, so I grabbed a bunch of the 2x4's and took them home with me tonight. I cut each tie to 19", slid them into the fixture, ran the router down each side, and onto the next. I laid them all out on the floor and tapped a couple of flat bars into the grooves, and I've got my first 10' of track!
At this rate I think I can make 10' in just over an hour. Well, straight pieces anyway.
I also test fit the bearings into the truck sides, and they fit great. I'm a little torn though, I'd love a prototypical look of the real truck, and the 6" channel has those edges facing outward that is spoiling that. But...I'd have to go with 1/2" plate to have acceptable lateral strength. Maybe, moving forward, I'll mill off about 1/2 the edge.
When I get back to work Monday, I'm going to download my pictures to photobucket and provide a link so you guys can have a look. My phone takes far too large pictures/pixels to attach here.

rkcarguy
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Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Fri Aug 25, 2017 11:51 pm

As for finish for the wood ties, I'm going to be using "uncle Larry's wood stain recipe". All I can say.

Glenn Brooks
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Re: 12" working railroad

Post by Glenn Brooks » Sat Aug 26, 2017 1:15 am

Regarding pixel size with cell phone photos: I also have way large image sizes with my iPhone. I email them to myself. The phone email software resizes large photos to smaller, acceptable web viewing size images before sending. When I receive the photos as an email attachment, I save and post. Much easier than messing around constantly with photo editing software.

Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....

rkcarguy
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Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Mon Aug 28, 2017 8:33 pm

I found a good deal on some 1-1/2" bore, 1" throw, spring extend, single action air cylinders online and ordered a couple. I'm thinking if I use these with some mechanical linkage combined with a pair of Kawasaki ZX6R front brake pads(they are square and have a pin hole, easy to "cage"), I can have brakes that will be set until I give them enough air to release them. I think this would solve a lot of issues, as when I unhook and park a piece of rolling stock, the air will vent and the spring inside the unit will force the linkage to clamp down on the pads/disc.
I'll have to play with pressures and maybe some additional springs to see when it takes a good set but it should work.

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BigDumbDinosaur
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Re: 12" working railroad

Post by BigDumbDinosaur » Tue Aug 29, 2017 1:29 am

rkcarguy wrote:I found a good deal on some 1-1/2" bore, 1" throw, spring extend, single action air cylinders online and ordered a couple. I'm thinking if I use these with some mechanical linkage combined with a pair of Kawasaki ZX6R front brake pads(they are square and have a pin hole, easy to "cage"), I can have brakes that will be set until I give them enough air to release them. I think this would solve a lot of issues, as when I unhook and park a piece of rolling stock, the air will vent and the spring inside the unit will force the linkage to clamp down on the pads/disc.
I'll have to play with pressures and maybe some additional springs to see when it takes a good set but it should work.
Sounds good. However, I must mention that the time will come, sooner or later, when you will need to be able to move the loco by pushing or pulling on it, especially if the prime mover is being obstreperous in one fashion or another. How will you release the brakes if no air is available?
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rkcarguy
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Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Tue Aug 29, 2017 11:04 am

I was going over that scenario in my head. Maybe have a hole in the linkage somewhere that I can pry it back, and insert a pin or something. Either that or I attach my portable air tank and release them that way. I have one of those 5 gallon tanks for topping up tires, also put a quick connect and a T fitting on it so I can fill it from my compressor.
I'd like to think I wouldn't have any engine problems, but you know how that goes. I took the 420cc apart when it was new and prepped it for racing, did a 3 angle valve job, honed the cylinder and set the ring gap(these things lack on the HF engines and can be too tight), and also replaced the carb with a 22mm Mikuni. It's got a billet flywheel, Honda ignition, MLS head gasket, "ported connecting rod oil ports" and 10.8 hardware throughout. It's currently got a 1-1/4" header with an old Supertrapp on it. As long as I prime the fuel system it's always started the first pull hot or cold. In fact I'm going to space the slide in the carb so it doesn't rev very high, because the governor has been removed and it will turn 6000 rpm if I let it.
As far as exhaust, I'm pretty confident that through a long and large exhaust system I can make the thing pretty quiet and deep. I'm thinking of doing several passes through a 6" tube muffler stuffed with rock wool and perforated metal, exiting into a 4x2x1/4 rectangle tube vertically in the position of the S-12's real exhaust stack. The tube will be open top and bottom, with the exhaust tee'd into the side, so rain doesn't fill up the stack, and therefore my exhaust and engine.

rkcarguy
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Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Tue Aug 29, 2017 12:35 pm


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BigDumbDinosaur
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Re: 12" working railroad

Post by BigDumbDinosaur » Tue Aug 29, 2017 2:37 pm

rkcarguy wrote:As far as exhaust, I'm pretty confident that through a long and large exhaust system I can make the thing pretty quiet and deep. I'm thinking of doing several passes through a 6" tube muffler stuffed with rock wool and perforated metal...
The muffler you describe is what we old-time hot rodders called a "glasspack," which usually doesn't dampen the high frequency component of the exhaust noise very well. See this post about an exhaust system that does dampen the high frequency noise with low back pressure.
...exiting into a 4x2x1/4 rectangle tube vertically in the position of the S-12's real exhaust stack. The tube will be open top and bottom, with the exhaust tee'd into the side, so rain doesn't fill up the stack, and therefore my exhaust and engine.
The bottom opening should be much smaller than the top opening to make sure exhaust gasses don't go into the interior of the locomotive. If you want to get really fancy, you could pipe that drain down below the deck so the interior doesn't get wet.
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I'm an old guy. What's your excuse? ☻

Glenn Brooks
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Re: 12" working railroad

Post by Glenn Brooks » Tue Aug 29, 2017 3:59 pm

I like your loco design. Similar to my favorite - early day SW 1500 road switcher. I looked up the specs on your proposed motor, and can't see a reason why you couldn't fit your 422 cc predator motor in the body if you design the frame and body to be somewhere around 20" to 24" wide.

Glenn
Moderator - Grand Scale Forum

Motive power : 1902 A.S.Campbell 4-4-0 American - 12 5/8" gauge, 1955 Ottaway 4-4-0 American 12" gauge

Ahaha, Retirement: the good life - drifting endlessly on a Sea of projects....

rkcarguy
Posts: 1376
Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Tue Aug 29, 2017 5:21 pm

Dinosaur, that's what I was referring to when I said several passes, i.e. it would go back and forth inside like that one in the link. I've played with a lot of pipes and mufflers on stuff in the last 20 years and when you want quiet, a straight through design isn't it.
The 1/6th scale I'm modeling gives me a 15" wide body and a 20" wide cab. The 420cc will fit sideways with about 1/2" to spare on either side only in the cab. Mounted the other way, the engine itself would fit but not the end of the crank, it would protrude out the side. Sadly it's about as wide as a V-twin but it's what I've got. With the pull start side facing the operator out the end of the cab, it will be easy to access the carb/choke as well.
FYI, I'm thinking of making the "fuel tank" into the muffler and just sink the rectangle tube all the way through it so no water goes inside, and yes I'll cap it at the bottom with a small hole so it can drain water. I have a remnant of 8x6x3/8 rectangle tube that's going to serve as the "fuel tank". I also got very lucky today, a scale measurement shows the exhaust stack needing to be about 4x1-1/2. I figured I'd have to settle for 4x2 as it's pretty common and the 1-1/2 is not, but the scrap bin produced a nice fresh piece of 4x1-1/2x3/16 about 3' long today:) I'm planning to cut some V-notches in the end, fold the sides in a little, and weld it back up so it has the tapered rectangle look of the stack on the real thing. If I decide to get really fancy I can even weld a little lip of round bar on it, but don't hold your breath.
I'd say the SW1500's and similar are one of my favorites as well. I remember saving my allowance for months as a kid, finally getting enough to get down to the hobby shop and buy an Athearn BB kit BN SW1500. Interestingly enough, I acquired an old Milwaukee road S-12 blue box #912 at the train show several years ago and have been taking dimensions from it to compare to the specs on the real thing and it's pretty accurate except for the stack(obviously for molding purposes). Honestly I went with the S-12 for this project because it has a taller hood, less windows, and no taper at the back of the body which will all make it easier to model and give me more interior space.

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ALCOSTEAM
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Re: 12" working railroad

Post by ALCOSTEAM » Tue Aug 29, 2017 5:29 pm

rkcarguy wrote:Here is my inspiration.
http://donsdepot.donrossgroup.net/dr1005/milw906a.jpg
That locomotive is a Baldwin S12

rkcarguy
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Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Tue Aug 29, 2017 6:04 pm

Next thing I'll need to deal with, I need a place to sit. I'm thinking of modeling a 34' gondola of some type with no ends, which would house the control stand and a pair of seats back to back, and would be permanently coupled to the locomotive. Then my other two pieces of rolling stock would be Bulkhead flat cars for hauling wood and trash, with removable "straddle bench's" for alternate use.

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