Large Scale Central

Onward the Pequod -- Getting a B'mann Railtruck to Work Permanently

For solder that won’t stick try some flux.

As Bruce says, flux will help. But it is probable that there is a layer of oil/grease on the brass. Get some emery or fine sandpaper, fold it in half and slide it on to the brass pin. Roll it around firmly until you have a nice brass color, and then try. (You do use solder with flux in it, designed for electrical use? Not plumbers solder with no flux?)

Bruce (@Bruce_Chandler) and Pete (@PeterT):

Thanks for the tips. I wish I had read them before I took anohter, ultimately successful, crack at it today while O.S. was busy converting a pillbox for the next round of nerf gun wars. I was, in fact, using flux with solder in it by luck of purchase and not by brilliant understanding, and I bought some brush-on flux today. It took a while, but no both wires are firmly attached. Next time, I’ll know to clean the lead to be soldered with some fine sandpaper…

O.S. joined me in time to screw everything back together:

…then we brought down Charlie to see how this all lines up:

In short, not well…

You can see the brass I bought for the drawbar running across the top. It is pretty stout. I am confident it can transmit thrust to the 'truck body. I’ve got to figure out how to mount it such that the vertical separation between the pusher car’s endbeam and the bed of the 'truck line up, it can swing around our R1 curves, and accommodate the less than occasional dips in our track.

I decide to bring things to a close run our Christmas-trains, enjoy a beverage, and prep for dinner rather than pushing on with this project.

Have a great week!


Grab one of these . fun to use.
I use it a lot for fractions etc.


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In fact, any time you strip the end of a wire that is going to be soldered somewhere, it is good practice to immediately “tin” it (put some solder on it.) That keeps the ends of the strands together, and makes a good base for the subsequent fix which may be days later.

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I assume this is a reference to O.S. doing arithmetic with fractions?

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OK. That triggered a thought or two. There are possibly 2 options:

  1. Make the coupler fairly rigid so pushing or pulling doesn’t make much difference.

This is a UK narrow gauge style hook coupler, and it can swing from side to side. They are sold by Accucraft UK. You would probably have to mount them so they swing a lot.

  1. I read an article a while ago about a pulpwood mill where the cars were coupled but had big rounded bumpers so they could be pushed. [The article was “S.D. Warren Paper Company Tram” in NG&SL Gazette, May/june 1987. I’ll email you the PDF.] Actually, the page was scanned as a PDF - what happens if I cut-and-paste it, I wonder.
    Well, that didn’t work!

(I’ll send you the full article anyway.)

Here’s how they did it.

As they were addressing the same problem, it occurred to me that bumpers like those could be fitted on the front of your pusher, under the end beam, and on the back of the truck bed. I think you’d need to make them fairly smooth so the side-to-side would slide, and fairly deep to cover the ups and downs of your track, exaggerated by the long overhang at the back of the truck.

Uploading: IMG_20211213_0001.pdf…

Absolutely! No point in wasting a good teaching moment!

@PeterT That could be a relatively simple solution. I could avail myself of already available LGB loops, which, while oversized, would be consistent with everything else on the Triple O, then see about fashioning rounded bumpers, perhaps clad in some sort of sheet metal so that they slide more easily across each other. Thanks!


I use my new “shock proof” camera to verify the downward acceleration of gravity is still 32.2 ft/sec2, so no photos…

We had to address the fact that the axels for the chosen motor block were too short relative to the journals, even in the exacting standards of1:24-ish PLAYMOBIL scale. I gave O.S. the option of redesigning the frame to bring the journals closer to the axels or of cutting extensions to the axels using brass sleeves. He opted for the latter.

I had some brass tubing, originally bought, to make journals for our cane cars, as it happens, that I allowed him to cut, measure, and grind to fit just shy of the backside of the journals. I even backed away and ran an errand while he took a crack at the project. He learned that rushing leads to poor results, which is a good lesson to learn on a scrap tubing rather than on an expensive model, so all is well.

He then took journals and the extensions out to the Palm of Spray Painting for a coat of black primer. He rushed, this, too and pronounced it “good enough.” His idea of “good enough” failed even my flexible standard, so these bits will get another coat. Again, not a bad or even expensive way to learn to take one’s time.

@PeterT , I’ve yet to show him that article you sent me. Frankly, I think those rounded bumpers are the only practical way to achieve the ends he wants. I may employ “parental privilege” and dictate this method to keep this project lurching forward. On the other hand, at $8 a set, those chopper couplings are awfully tempting…

Pictures when I can, updates as required!



O.S. got the journals and “axle extensions” painted, and, in the process, gaining a lesson in proper distance between spray can and object to be painted. In truth, the journals look about as grimy as some of the improvised MOW equipment at the railway society, so all is well:

He was all set to glue the journals to the frame, when I showed him that they did not align vertically with the axles. The gap is “craft stick thick,” and, craft sticks being a preferred building material, we had scraps in abundance to glue to the frame:

We should be able to mount the journals tomorrow.

O.S. also read Pete’s recommended article, and we will attempt to shape rounded bumpers to serve as part of our coupling system. I think LGB “loops” mounted beneath those bumpers lashed with some sort of chain will complete the look.

Now it is time for me to “ante up” and get that battery system and start thinking about lighting!



Charger, harness, and battery on order from RLD. Shipping batteries to Hawaii is not cheap :frowning_face: The Magnetic Critter Controller is on hand for when they arrive, so we can start eyeballing the electronic layout! We’ll return to this project in earnest after the MIK.



The still-wet glue on our MIK project gave O.S. and I to reattack this project.

First, we checked to make sure the new battery will fit:

Yep. Of course, we forgot the circuit board for the magnetic controller, but there is plenty of space. There are also nice long leads to the motor, which is fortunate, as our leads have both fallen off!

We then did a test to see how some knuckle coupler’s from @Pete_Lassen would look…

…and we confirmed that even in 1:24-ish PLAYMOBIL scale it would look bad. There is just too much distance between the pusher car and Charlie for our taste.

That brought us back to @PeterT 's suggestion to use rounded bumpers. O.S. found the last wood that was to go to more cane cars and cut them to size.

Even I can cut more of these! O.S. noticed that, in true Eric fashion, some of my cuts were straight in a non-Euclidean sense. This allowed them to line up better with the pusher cars bumper when laid across Charlie’s deck. He glued and clamped the bumpers together. The result looks like this:

We will need to round the bumpers, of course, and I may tap a couple small wood screws into them. Then we can cover them with left over aluminum from the mill project. The final bit will be some sort of hook beneath the bumpers to keep the 'truck from running away from “his” pusher car at station stops.

We did discuss routing power to the remnants of the circuit board to see if the lights still work. We also discussed a DPDT switch for forward / reverse. To be frank, I am not sure how much effort I want to put into the former, and I am not sure how well this rig will work in reverse.

This project is a backburner project as we train our main batteries on the MIK! Updates will be coming, just not quickly!


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could the couplers work under the added wood, and give a closer together look? I also have some USA couplers which could work a little better, depending on where they attach

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@Pete_Lassen : Thanks, Pete. I think, in the end, “large scale” couplers of any kind (1:20.5 - 1:24) will look a bit large. The 1:24 crew and I posed the couplers on hand as though they were mounted under the extended bumpers…

…and you can see there would be little to no vertical clearance.

We’ll get these bumpers rounded as we wait for bits and pieces of this year’s MIK to dry and figure it out.



With the MIK astern of us, we can return to this project. While “MIK-ing,” it occurred to me that putting batteries and circuit boards in the 'truck and running them over the stern to the pusher car was only inviting disaster. I am sure there are numerous easy-to-install quick disconnects with which to experiment, but, upon returining to this project, O.S. and I simply tried to fit it all in the pusher car:

Ummmm…yeah…let’s do that!

O.S. was amenable, so the next step was to trace,

…cut, and shape the bumpers:

I actually had to help him. It is nice to know I am needed! We did glue on some left-over annealed beer can to serve as a metal sheathing, too. Tomorrow, O.S. will shape the other bumper. I have found he is good for about 30-60 minutes on these projects. No point in making him resent this!

Today, with O.S. and his buddies off campaigning against Vercingetorix, I took another crack at the motor block. My soldering was insufficient. I looked at the wire gauge for the electrical harness from RLD, rummaged thruogh my wire bucket to find something similar, and got out the soldering iron. I tinned it. I lathered it in flux (Whatever this stuff is, it is magical!), and lo!

While I was in there, I removed the electrical pick-up shoes and discovered that the axels sit in square bushings you must carefully align to get the motor block back together. Hmmmmm…Still, this motor block is a lot closer to the elegant simplicity of LGB or PIKO than the spaghetti bowl of B’mann.

We’ll get the other bumper shaped tomorrow, then I am going to set O.S. to on the gondola walls that will house the electronics. Progress will be at the pace of his interest, so we’ll see if this picks up steam.

Enjoy the rest of your weekend!


What about a pair of O scale couplers or just a drawbar?

Bob (@wengnut ),

We will look for O-scale couplers on our next sojourn to the contiguous 48. I also have the material to fashion a drawbar on hand, but my metal cutting tools are limited to a Dremel and a rasp, so it’ll be a bit crude! I am actually thinking of some sort of “hook” like you might use to secure a cabinet drawer.


P.S. I forgot to mention, O.S. shaped the other bumper, clad it in old can, and scored and cut off plastic that will be seen after he makes the gondola walls.

One quick question before we proceed. Should we mount the battery to the plastic deck, or should we elevate it a bit using some scrap wood to allow air to get under and cool it? The G Scale Graphics card comes mounted on a board for the purpose of cooling, so it seemed wise to ask!

Have a great week!


I never worried about cooling the batteries. All of mine are flat on the surface.