A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

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dajt
Posts: 17
Joined: Sat Dec 01, 2012 2:34 am

A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by dajt »

Hi all.

I just looked at my profile and find I joined nearly two years ago and have not made a single post despite gaining much enjoyment from reading the threads. So here I go.

I have a freelance 0-4-0 in 5" gauge of indeterminate scale that we call a Blowfly here in Australia. I bought various bits from various places but most importantly the boiler, a pair of cylinders, and most of the bodywork were done so I just had to build the chassis to get a running loco. It was quick way to get into the hobby and that loco has been an excellent learning experience in terms of the basics of making parts and maintenance. I already knew how to drive a boiler as I used to be a stoker on a little steam launch on Sydney harbour before moving to the country, and sometimes drove my father-in-law's locos.

But I want a proper model so got myself involved in a group project we have going here to build a NSW freight mogul. There are about 4 of us actively building our models with a few others receiving the drawings and instructions but busy with other things. I'm lucky that I live in the same town as the guy designing it so I can go see the 'prototype' model and ask questions whenever I need.

I've been working on the tender for nearly 3 years, but nowhere near concentrating on it for most of that time. I didn't take any photos of progress but now it is nearing completion I thought I'd start a thread for it and the loco to come.

The chassis frames were laser cut from CAD drawings I did based upon the paper drawings by the designer. The wheels and brake shoes are castings and the buffers commercial turnings. Everything else was made in the shed.

Regards,
David.
Note the Blowfly in the background.
Note the Blowfly in the background.
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Pontiacguy1
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Joined: Thu Apr 26, 2012 10:15 am
Location: Tennessee, USA

Re: A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by Pontiacguy1 »

Nice looking locomotive. That tender looks pretty nice. Shame to have to paint something so shiny!
dajt
Posts: 17
Joined: Sat Dec 01, 2012 2:34 am

Re: A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by dajt »

Thanks!

I've often thought the same. They do look pretty special when they're all shiny. Maybe just a few coats of varnish?

I only used brass due to the flare around the top. I don't think I could have bent steel to get the same effect. There were a few other bits I tried to make from steel and ended up redoing in brass for that reason.
dajt
Posts: 17
Joined: Sat Dec 01, 2012 2:34 am

Re: A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by dajt »

Got the sandboxes done over the last few days, now finishing up detailing on the brake cylinder sub-assembly.
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Nearly as many rivets underneath as on top.
Nearly as many rivets underneath as on top.
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dajt
Posts: 17
Joined: Sat Dec 01, 2012 2:34 am

Re: A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by dajt »

So onto the loco!

The frames are cut with a water jet in 3mm steel. The horn cheeks also cut with a water jet from 10mm steel, with just some machining to make a relief for the nuts on the back of them.

The drag beam and buffer beam are also 3mm steel, cut from some 3x100mm flat and the drag box was welded up and then machined back to something like square from 5 & 10mm steel. If I was doing it again I'd try and get some solid steel of near enough size and drill/mill out of the cavity.

I knew the buffer beam would be a trial, and I now have the headache to confirm it. Laying out the holes was easy after fitting a DRO to my milling machine, but trying to get the buffer beam rivetted to the front stretcher with 3.2mm rivets cut from welding rod, while the horizontal and vertical relationship to the frames was maintained seemed a stretch for my meagre ability.

Despite much care and about 6 of the 1/16" cosmetic rivets in place to keep alignment, and a clamp, it didn't work. The two parts somehow shifted and the real rivet holes were off by about .010" to .020" so I had to plug them, and try to redrill. Broke the drill on the 3rd one and 3 rivets is all it's getting. The last big rivet hole in the buffer beam will be hidden by the square plate that surrounds the coupling hook hole.

Anyway, it looks about right when on the loco so that's good. The top suface of the front stretcher may be a bit high or low when the time comes to put a bit of plate on it level with the footplates outside the frames, but I'll bodge that when I get to it.

Regards,
David.
Attachments
Note the brass shim. Despite all care the front frame stretcher ended up somewhere like .015" back from the front of the frames so the shim is required to stop the buffer beam bowing.
Note the brass shim. Despite all care the front frame stretcher ended up somewhere like .015" back from the front of the frames so the shim is required to stop the buffer beam bowing.
I bought the buffers. The masking tape is holding some dummy rivets in place to "help" with alignment.
I bought the buffers. The masking tape is holding some dummy rivets in place to "help" with alignment.
dajt
Posts: 17
Joined: Sat Dec 01, 2012 2:34 am

Re: A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by dajt »

I have done most of the frame spacers now, just the one above the leading wheels to go. Also getting through the axle boxes. First two with their bushes loctited in. The two rear ones still have to be thinned down to allow the firebox to fit between them.

Up to 108 hours on the loco.
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dajt
Posts: 17
Joined: Sat Dec 01, 2012 2:34 am

Re: A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by dajt »

Some progress on the axleboxes and wheels. When the eccentrics are done I can put the wheels on, and push it around :)
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NP317
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Re: A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by NP317 »

Good looking work, and a nice model. I'll be watching your good progress.

It seems so pleasantly simple to use springs and no equalization. Our USA prototypes require equalization due to endemic rough track conditions here during those years, unlike "more civilized" railroads around the world. ((-; So our model locomotives require many small hidden parts to be "correct."

Rolling soon I trust...
~RN
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Fender
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Location: Chattanooga TN

Re: A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by Fender »

dajt wrote: Despite much care and about 6 of the 1/16" cosmetic rivets in place to keep alignment, and a clamp, it didn't work. The two parts somehow shifted and the real rivet holes were off by about .010" to .020" so I had to plug them, and try to redrill.
This is actually a common problem with riveting. Unless I misunderstand your problem, there are several things you can do to avoid the hole misalignment:

1. When riveting two parts together, fasten the two parts along the whole length of the rivet holes with about 10% of the holes filled with tight-fitting screws or clecos (I prefer clecos). Then put in a rivet on one end of the assembly, but don't over-form the rivet. Just form the head enough to secure the rivet in place. Next, put another rivet on the other end of the assembly the same way.
2. Next, put in a rivet about halfway between the first two. Keep putting in rivets halfway between the others until you have (more or less) every other rivet in place, before putting in the rest of them. The objective is to keep the holes from "creeping" out of alignment because one piece is stretched more than the other. By proceeding this way, the misalignment from the stretching is distributed evenly along the length of the row of rivets and you should be able to get the holes to align (with just a little re-drilling).
3. When all the rivets are in place, you can finish forming the heads.

This method has worked well for me.
Dan Watson
Chattanooga, TN
dajt
Posts: 17
Joined: Sat Dec 01, 2012 2:34 am

Re: A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by dajt »

NP317 wrote:It seems so pleasantly simple to use springs and no equalization. Our USA prototypes require equalization due to endemic rough track conditions here during those years, unlike "more civilized" railroads around the world. ((-; So our model locomotives require many small hidden parts to be "correct."
~RN
Nothing much civilised about our railways! It just took a long time for us to admit our track was more like yours than Britain's and use the appropriate locos. There was a lot opposition to using US locos for ages, and people lost their jobs for trying.

You'll see 5 small holes between two of the axles which were for an equalizing beam that was done away with by the time the loco was in the modelled state.

My father-in-law built a model of one of the few NSW Baldwins and I did the frame drawing for it. Those bar frames certainly have a lot more air than metal!

Regards,
David.
dajt
Posts: 17
Joined: Sat Dec 01, 2012 2:34 am

Re: A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by dajt »

Thanks Dan. I use that method when doing the small rivets, but did not think to do it for these larger ones. I figured there were only 4 holes, what could go wrong?

It was not so much a case of one piece deforming as the two being out of alignment from the first hole.

I need to look up clecos.

Regards,
David.
dajt
Posts: 17
Joined: Sat Dec 01, 2012 2:34 am

Re: A NSW 24 class mogul in 5" gauge, 9/8" : 1' scale

Post by dajt »

I've just come back and marveled at the Walt Disney American thread again. So to show the last 5 years were not idle here is the loco in its current state.

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It runs on air and the boiler is done aside from the superheaters, and the regulator needs soldering together but the parts are made.

One of the trickier bits was the reversing screw. I was really pleased with how the screw itself turned out. The bracket it sits on is a bit out of alignment in many ways but I'm trying to convince myself to live with it. I made the tap from silver steel (water hardening drill rod?). It is a square thread, LH, 2 start.
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Regards, David.
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