Large Scale Central

Project #4: The LGB2018D-Mason Bogie

Project #3 is a part-finished UK teak coach, which needs glazing and lots of outside beading. As my LNER B1 is stuck in MD and I have nowhere to run a beast like that in Florida, it has been relegated to being a Spring job.

So on to Project #4, the LGB2018D Mogul made in to a Mason Bogie:

When I inquired, I was told there was a UK guy who put these together. Nice brass chassis, delightful cab, a 6-wheel truck from combining 2 x 4-wheel trucks, and a central pivot for the boiler. The loco behind is a proper Fn3 model of a Mason, made by Rishon many years ago. The LGB 2018D is a bit bigger.

The loco has been sitting since 2022, before hurricane Ian halted all work in my condo. Before that time I acquired a spare wooden cab and a proper 6-wheel truck kit, left over from the MLS Mason Bogie class. I think they came from our BD (@rmccown-admin). I did build the truck and installed it.

However, you’ll note the “DSP&PRR” in that early photo. Whoever made it used the whole tender which threw off the proportions, so I had cut down the frame and mounted the truck. I cut the old tender down on my mini table saw. Here’s how it looked when I moved in a few weeks ago.

The spare tender had been acquired last year as a replacement for the side that I cut at the wrong place. This time I plan to have DSP&P on both sides!

You’ll also note the droop of the smokebox. The Mason has a pivoting frame, so there is no smokebox saddle to support it. A final solution has not been found.
What I did find was a plethora (!) of wires, most of which I removed. Many had connectors, except for some unknown reason the wires to the headlight. So the first task was to add a connector so the whole smokebox could be put to one side.

You might notice the brass plate inside the boiler. That’s the ‘floor’ for the battery pack - the pink 18650s visible in the prior pic.
I found a bad solder joint in the modified frame, so that’s next. Then new paint on the frame and chopping of the tender.

Looks good. Yea, I think I sold you at least the truck kit, if not the cab. That was the beginning of my “I’m never going to get around to building this in my lifetime” project cleanup.

The truck looks great!

Finally got some bench time away from the endless Christmas activities (buy new tree after the old one floated away in Ian, etc.)

I started marking the tender, but I haven’t cut it yet. The original had a bunch of holes in the back for various switches, like the headlight (?) You can see them here:

So I had to start figuring out where the various switches would go. Interestingly, my new tender has a flat top, and the original (which I cut 3 1/2 years ago) has the top cut out. After pondering for a couple of days, I see no reason why the tender can’t keep it’s top, and I’ll mount the track/battery, on/off/charge and any other switches on the top under the top frame with the fences and coal/wood load. More on that when I get around to it.

As mentioned in my first post, I had to figure out how to attach the side of the frame to the strip supporting the firebox. I tried acc, and it didn’t take.

The side of the frame is very thick brass so I got out my mini-torch. It refused to fill with butane, and refused to light even when I thought it had some butane. Something happened since last time. Oh well, Harbor Freight has the little handheld for peanuts.
And I also thought I would probably demolish the frame if I started heating it with a torch, not to mention burning the paint.

So I drilled a hole 1/16th and tapped it M2 [very close size - the 1/16th is larger but the hole will take the threads.] And I went looking for a hex-head M2 bolt. Nope, not in my steam-up toolkit, nor my small fastenings box, nowhere. So I had to use a round screw head.

I’ve ordered some bolts, and I can swap it later. One problem is that if you search for hex-head bolts, you get round cap screws with a hex hole in them. Sigh.

A side question for you electrical experts. I have a bunch of slide switches, but most are rated 0.5A at 50V or similar. I did notice that similar switches are rated 0.25A at 100V (e.g.)

Is a switch rated 0.5A at 50VDC good for 1A at 25VDC, or 1.5A at 18VDC?

Depends on what you are turning on ?

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Sadly, switches generally don’t derate like this. Some datasheets will even specify a minimum current (“wetting current”) the device needs to switch to guarantee a long service life.

Generally speaking, AC current ratings will be higher than DC current ratings, since it’s easier to stop an AC arc than a DC arc - the alternating polarity tends to extinguish an AC arc.

Here’s an example of a single-circuit on/off toggle switch that will switch up to 4A at 30V DC, with the minimum current/voltage being 0.1A at 2V DC. https://www.digikey.com/en/products/detail/nkk-switches/MN11S2A1W01/20838938 (No affiliation, this was at the top of the list when sorting by price low to high after setting the Digikey filters).

I defer in depth knowledge to Benjamin, but to be honest, when doing a model RR install I’ve never really paid any attention to the ratings. I usually buy based on size and function. The last toggles I purchased that have been used in many of my RailPro conversions were SPDT toggles with only an AC rating of 5A at 125VAC or 3A at 250VAC.

What you risk with an under rated switch is failure in either the open or closed state. If this will be a keeper for you I’d go with what you have and risk it. If you are building for resale, then buy heavier switches for $.50 to .60 each in small quantities on Amazon.

Unfortunately Pete, no. Voltage is voltage - as long as it’s rated well above whatever your using. Current is what you need to switch. Use a safety margin (or risk early failure).

There’s a whole lot more behind it, as Phoxtane is suggesting - but that’s the gist of it.

Cheers
N

Thanks David, but I already found some at Accucraft slightly cheaper than that (!)

Oh well. Guess I need some 5A switches.
Apparently my local Ace Hardware sells slide switches for vacuums (!) I’m going in this afternoon so I will see what they have.