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.

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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.
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NP317
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Location: Northern Oregon

Re: 12" working railroad

Post by NP317 » Thu Feb 22, 2018 10:54 am

Looking good!
~RN

rkcarguy
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Re: 12" working railroad

Post by rkcarguy » Thu Feb 22, 2018 9:53 pm

I had some fail today, I took some measurements last night for couple strips of aluminum to shear up and then took the wrong material with me to work.....040" instead of .060". No train work tonight:(

rkcarguy
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Re: 12" working railroad

Post by rkcarguy » Tue Feb 27, 2018 9:54 pm

Well I got the pieces cut from the *right* material and got them riveted in. I don't want the grille frame to grow lumps between the screws as its pretty thin material, so I'm going to remove it tonight, transfer all the holes to the mesh grille piece so I can shear and punch it to fit, then rough up one side of the grille frame and JB weld it to the body. Hope I have enough JB...
Also got another freebie from work. We built a gate awhile ago, which called for 3/8x1 flat bar infill in it. The bars were bent during handling and couldn't be straightened to be "architecturally" acceptable, and just sat outside rusting since August. My boss gave me the ok to take it home(it's my rail size), so I've got enough for another 40' of track:)

rkcarguy
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Re: 12" working railroad

Post by rkcarguy » Wed Apr 04, 2018 12:15 pm

Not much to post as of late. The new CNC plasma table at work is up and running, but we are super busy so I haven't had any time to get any parts made yet. I want to re-do my truck sides in plate, and the complexity of the design I came up with should really be laser cut or at least plasma cut and etched so I get the bolt holes and slots in the right places. My design is a rigid inner frame of plate and pipe, with pockets grabbing the tops of the springs and vertical slotted holes, then the truck sides with pockets grabbing the lower end of the springs, which bolt onto the inner frame with 4 bolts per side(just snug) and thrust washers so the truck sides can articulate up and down in the slots and twist to stay on track.
I think I'll re-purpose the channels I had made originally for my truck sides with the pillow block bolt patterns, as a stand for checking/grinding my wheel sets, and a small MOW car, possibly for grinding the 1/8" radius on my FB rails.

rkcarguy
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Re: 12" working railroad

Post by rkcarguy » Mon Apr 30, 2018 12:07 am

Finally got the mesh installed for the grille.
s12grille.jpg

rkcarguy
Posts: 541
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Re: 12" working railroad

Post by rkcarguy » Mon Apr 30, 2018 12:08 am

Need to get my pliers out of the inside lol

rkcarguy
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Re: 12" working railroad

Post by rkcarguy » Tue May 01, 2018 4:19 pm

I did some more measuring and scaling of the HO scale model this weekend, and figured it's time to get the chassis fabrication going.
The sides of the fabricated frame S-12's scale to 2-3/8" tall(there was cast and fabricated frames), so I'm going to utilize 3-1/2x2-1/2x1/4 angle for the sides of the frame which will also be the walkways along the side of the body(2-1/2" leg vertical facing out, 3-1/2 leg will be the walkway surface). I drew up cad dwgs of the bulkheads/steps with all of the perforations for air lines bolts electrical and coupler pockets into the laser cutter to be cut from 3/16" plate. A remnant of C8x11.5 will span across the angles in the center picking up the "fuel tank" muffler. Under the deck plates on each end a short chunk of C10x15.3 and the steps themselves will tie the two bulkheads together. Then two chunks of C4x5.4 will span side to side to pick up the bolsters on the trucks. Finally once all the guts are mounted on the chassis, I'll fabricate a frame/cage that will bolt over everything and really stiffen up the chassis. The area's under the steps will be hollow and measure about 10"x4"x3", and once everything is together I'll be able to fill this up with stacks of plate if I need more weight.

rkcarguy
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Re: 12" working railroad

Post by rkcarguy » Wed May 09, 2018 11:40 pm

I found a couple remnants of angle long enough for my frame sides, and got them cut today.
The laser cut "bulkheads" are about a week out. I made slots in the bulkheads for 1/4x2 flat bar(steps) to slide through, which will then be plug welded and ground smooth so there is no "giant" fillet weld on the steps to the bulkhead.
The short piece of C8 I had spotted unfortunately ended up in the scrap dumpster and the lid was closed(no dumpster diving :oops: ) as it's getting picked up tomorrow. I ended up drawing a plate which will have an 8" flat center and 45* upward sides, with 4 short slots to pick up the fuel tank muffler and allow me to center the tank between the trucks if anything ends up being off a little bit. I'll plasma cut this on the Arclight when it has a time slot open.
I spent my lunch break drawing in the hydraulic motor from it's spec sheet, a chain and sprocket "route", and a bracket for the hydraulic motor for each truck. I also took and notched the bottom of my truck sides (in CAD) so that the wheelsets with pillow blocks can be dropped out of each truck for service without removing the truck or taking it apart. As the reveal is only 1/8" past the pillow block casting, I don't think it will be very noticeable and it will make things much easier to work on.
I'll upload some screen shots from CAD if anyone is interested.

The only back-peddling ended up being from the machine shop. I was hoping that by supplying some nice circular plate burnouts I could have the local CNC shop economically grab them and turn the front face and wheel surface to the flange, then bore the center hole...even roughly as I have the a reamer for my finish size. Then after I had them shrunk fit on the axle I'd turn the back and outer diameter of the flange. Sadly pricing came back at $90 a wheel, so I'm going to need to keep looking, or maybe get a Saturday at work on our lathe and run each one manually.

rkcarguy
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Joined: Tue Aug 22, 2017 10:33 am

Re: 12" working railroad

Post by rkcarguy » Thu May 10, 2018 11:06 am

AARtrucks.jpg
I don't have the chain and sprockets drawn in that connect one wheel-set to the other in this drawing.

rkcarguy
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Joined: Tue Aug 22, 2017 10:33 am

Re: 12" working railroad

Post by rkcarguy » Fri May 11, 2018 10:58 am

In the past I know I've discussed my hydraulic motor location and chain drive reduction with BDD. I wanted to get my hydraulics up inside the body and out of the elements, being this locomotive will be used in pretty much any conditions that USPS would deliver the mail. Secondly, by changing the sprocket on the motors, I can fine tune the speed and torque availability as needed, instead of having to change my pump.
If I was modeling in 1/8th scale/1.5", with 5" wheels, the math looks good for a direct drive or 1:1 ratio setup from the hydraulic motor, but incidentally the sprockets I'm starting out with reduce my axle RPM accordingly for my larger wheel size at 2" scale so I have about the same overall track speed using wheels that are 7". The other bonus is that my idle speed rpm is going to translate to about 50 rpm at the hydraulic motor, but is going to be dropped to around 32 rpm at the wheels, so I will have a slower track speed at idle. Speed range will be, in theory, 58 to 580 feet per minute.

rkcarguy
Posts: 541
Joined: Tue Aug 22, 2017 10:33 am

Re: 12" working railroad

Post by rkcarguy » Wed May 16, 2018 6:41 pm

bulkheads.jpg
The bulkheads are here, 1/4x2 flat bars will slide into the rectangular slots and get plug welded to form the steps.
The inner plates have the three upper holes for electrical and other future unforeseen needs, and the outer plates have the coupler pocket opening, hole for electrical, hole for a D-ring for the safety chain, and hole for the air brake fittings.
The four holes along the bottom are for a piece of 1-1/2x1-1/2x3/16" angle to attach to help beef up the bottom of the plate in case of an impact, and also look somewhat like the real thing on the S12.
I have seen the coupler opening "open" clear to the bottom, and others plated closed except for the opening itself on various S12's, so I opted for the minimal coupler opening as I think it looks better and I can always cut more out later if I need to.

rkcarguy
Posts: 541
Joined: Tue Aug 22, 2017 10:33 am

Re: 12" working railroad

Post by rkcarguy » Thu May 17, 2018 10:58 pm

Today I discovered another short piece of C12x14.3 in the scrap pile, so I grabbed this one and set it aside for my center cross member. Also got the channels cut and put them through the shot blaster as it had sat outside for years....hey free is free, and it looks almost like new now and there is no mill scale to deal with. That will support the trucks on the frame of the locomotive and riding car. Just have to cut the C12 to length, some coping to do, and the frame will be ready to start welding together.

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