New 3/4" Scale Track - Part 1

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Andy R
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Location: So. Calif.

Re: New 3/4" Scale Track - Part 1

Post by Andy R »

Wonderful !
Enjoy many, many hours of steaming.
steamingdon
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Re: New 3/4" Scale Track - Part 1

Post by steamingdon »

Very nice job, A lot of very hard work. I wish you good steaming for years to come.
steamer
Andypullen
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Re: New 3/4" Scale Track - Part 1

Post by Andypullen »

Nice looking track Eric!

Is your G5 built from the Mahar plans?

Andy Pullen
Clausing 10x24, Sheldon 12" shaper, ProtoTrak AGE-2 control cnc on a BP clone, Reed Prentice 14" x 30", Sanford MG 610 surface grinder, Kalamazoo 610 bandsaw, Hardinge HSL speed lathe, Hardinge HC chucker, Kearney and Trecker #2K plain horizontal mill, Haas TL-1 lathe.
PRR G5s
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Re: New 3/4" Scale Track - Part 1

Post by PRR G5s »

Thanks guys!

Andy, no, it was not built from the Mahar plans. I scaled up the drawings in Model Railroaders Steam Locomotive Cyclopedia, and then fit the Little Engines cylinders to the frame. The valve gear was redesigned by one of my mentors, Wil Wright. I drew the boiler making a lot of assumptions, and Paul Brien of TN looked at it and said it would work. I didn't build the boiler though, one of my other mentors, Ed Painter built it for me.

I learned quickly how little I knew about how a steam locomotive works, even though I thought I did. I had a lot of mentors help me build this engine. If it weren't for them, it never would have been completed. Nor would my second engine. Although it's not quite done, it runs. It doesn't have all the detailing on it.

Eric L.
Wayne Davis
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Re: New 3/4" Scale Track - Part 1

Post by Wayne Davis »

Is this the 282 I saw in one of your posts? Can you post a current picture of it also?

Wayne
PRR G5s
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Re: New 3/4" Scale Track - Part 1

Post by PRR G5s »

Wayne,

I think you might be thinking of someone else. The G5s is a 4-6-0 ten-wheeler.

Eric L.
sky
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Joined: Thu Mar 22, 2018 2:17 pm

Re: New 3/4" Scale Track - Part 1

Post by sky »

I am building Kozo's A3 switcher in 3/4" scale and want to run on propane or such.
How do I convert it?
sky
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Bill Shields
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Re: New 3/4" Scale Track - Part 1

Post by Bill Shields »

this is one way...is a Sievert torch head....
80 psi and no problems.jpg
OS used to sell this kind of option out of their catalogue.

granted, this is not an A5...but the concept is valid...and it you are going to consider it...think about FIREDOOR size before you build the boiler.

beyond this, the 'conversion' can be involved since you need to obtain / build a burner that will fit.

Bill Moorewood did it for his Raritan, but darned if I ever saw his burner out on the ground.
Too many things going on to bother listing them.
UPsteamfan
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Re: New 3/4" Scale Track - Part 1

Post by UPsteamfan »

PRR G5s wrote: Mon Nov 30, 2020 1:37 pm Apparently, the plastic ties “shrunk” after fastening the rails, so the gauge was too tight. I ended up spending the last 3 weeks regauging the whole track, which was not fun.
I brought this up to my father who is the head track guru on the Maple Leaf Railroad. We are soon to start the task of build our track also using plastic ties. Our goal is year round running on 10+ miles. Not something we want to reguage. That said on our 14" long ties, expansion is 1/8" guage is 7 1/2" which has expansion of 1/16". The rail is aluminum and will expanded about 1 1/2" over the 144 inch length of a passing siding.

Do you have any gaps in the rail at the joints. This would allow for the rail to expand without pushing the gauge out of alignment.

Let me know if you have any questions
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kcameron
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Re: New 3/4" Scale Track - Part 1

Post by kcameron »

There was an article published about the Maracopa club and their standards for gapping. I don't remember which publication it was in. They did like the prototype, built a table showing rail temperature and the gap to set. The table covered 30F to 140F I think, based on the range of temperatures they usually see down there. Now the prototypes go as far as how much tension should be in the rail too. One part of the year you might have to clamp and push the rail apart, other times clamp and pull on it around the joints.

But I recall since we use aluminum rail at the too ends of the temperature curve, you can't put more gap or you stop leaving any gap, and hope it holds. You shape the curve to cover your typical range as best as possible.
-ken cameron
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UPsteamfan
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Re: New 3/4" Scale Track - Part 1

Post by UPsteamfan »

That is what we are doing as well. Normal running between 30F and 80F, build to that and hope for the best in the rest of the range.
PRR G5s
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Re: New 3/4" Scale Track - Part 1

Post by PRR G5s »

UPSteamfan,

Yes, there are gaps at every rail joint. Similar to what Maracopa did, I developed a table of rail gaps based off rail length, “setting” temperature, with a maximum temperature of 100F.

The problem is that the expansion/contraction rate of the plastic ties is about 4-5X wood’s expansion rate. Being elevated compounds this expansion/contraction, because unlike on the ground, there is nothing to dissipate the heat. I did consider the expansion of the ties when selecting the plastic ties, but thought the expansion wasn’t going to be an issue. Unfortunately, I wasn’t thinking about contraction. But then I didn’t think I’d be running when it was 45F-50F.

Eric L.
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