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.
rkcarguy
Posts: 960
Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Wed Dec 12, 2018 11:09 pm

Tonight I stayed after work and TIG welded the spring perches into the "equalizer bars". I also pressed my 1/2" stainless bolts into the holes and TIG welded 2 of the sides of the hex heads to the equalizer bars. The stainless was necessary, because it has a much higher enbrittlement temperature than steel so they won't break off. I wanted to grind the edges of the laser cut truck parts tonight and toss them in the roto-blaster tomorrow, but I have to do it outside and it's windy and pouring rain again so I'm going to have to wait.
I'm not sure if everyone understands how my locomotives trucks will function, but basically the pillow blocks(self aligning) will mount to the equalizer bar. The SS bolts act as studs which will protrude through vertical slots in the inner truck side/frame, with some bronze washers in between and the nut finger tight, so that the equalizer bars are loaded by the springs and can travel up and down in the slots.
I'll update with some more pictures shortly.

rkcarguy
Posts: 960
Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Wed Dec 12, 2018 11:29 pm

Pics
S12trucks.jpg
S12trucks2.jpg

rkcarguy
Posts: 960
Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Thu Jan 03, 2019 6:17 pm

Things went a little backwards today. I went to power-tap the pillow block mounting holes 3/8-24 in the "equalizer bars" shown above and hit some kind of inclusion in the plate, messed up my TICN coated HSS tap, and part of the threads in the first hole I tried. A bolt still threads in, but it's a little loose and 1/3rd of the threads are gone in the hole. I do not have room for a nut behind these, so I may have to drill and tap this one oversize and make a threaded sleeve to fix it ugh.

rkcarguy
Posts: 960
Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Wed Jan 09, 2019 12:43 am

Things are starting to come together now. I welded the upper spring perches and bolsters into the inner truck sides, and bolted the cross tubes in.
Here is some pictures of how they will go together. I still need to blast the assemblies and make/buy some thin bronze thrust washers to go between the moving parts, and tap the rest of the pillow block mounting holes in the equalizer bars.
The frame pieces are also nearly complete, I have to grind the welds smooth on one of the pilots and drill/tap the coupler box mounting holes, and the frame will be ready to weld together. It's too long to fit in or roto-blaster, so I'm going to talk to a couple of paint and powder coat shops to see if someone can blast it for me reasonably.
S12truckasm1.jpg
S12truckasm2.jpg
S12truckasm3.jpg
S12truckasm4.jpg

rkcarguy
Posts: 960
Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Fri Jan 11, 2019 1:49 am

Got the inner truck assemblies all roto-blasted and primed with etching primer.
S12trucksprimed.jpg

rkcarguy
Posts: 960
Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Tue Jan 15, 2019 4:31 pm

I took the plunge and bought all the hardware for the locomotives trucks. This was a rather expensive venture for what it was, about $78.
32 bronze washers for the 'sliding" action of the truck suspension, normal and thin lock nuts for everything, and button head socket head screws for the pillow blocks and spring retainers all around.
Next on the to-do list is to flap wheel the bores slightly larger on all the pillow block castings so the bearings "self-align" much looser so there is no binding as the trucks conform to variances in the track, and then I can mount the equalizer bars and pillow blocks on the frames, insert the springs, and call those done until I get wheel sets.

rkcarguy
Posts: 960
Joined: Tue Aug 22, 2017 10:33 am
Location: Wa State

Re: 12" working railroad

Post by rkcarguy » Thu Jan 17, 2019 11:36 am

I got the power tapping to work on the drill press. Apparently in the lowest speed my center pulley doesn't adjust enough and the belt slips, so I had to crank it up to the next speed. Thankfully this is 3/8-24 fine threads so it wasn't that scary. No reverse obviously so I just loosened the chuck and then removed the tap with my tap handle. Two more bars left to tap the holes on, and then I can paint these and mount them.

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