Another N Scale Whitcomb…This time a 44 Tonner

[Jim Starbuck]

New thread moved over from Weekend Update …

Well I hope you all aren’t too tired of hearing about Whitcomb switchers.
These have always been favorites of mine especially the Milwaukee 44 tonners. I acquired a 45 tonner from Mark aka Elgin Locomotive Works thinking it would be as close as I would ever get. That build went well and it’s actually ready for paint. During the 45 build lo and behold a friend designed and printed the elusive 44 tonner from plans in the MR Locomotive Cyclopedia. His prints are outstanding and I couldn’t wait to get going on this long awaited project. (sorry 45 Tonner, you’ll have to wait).
The sill was a blank slate to power it with ample room for the preferred 7x16 double shaft coreless motor. Bachmann 44t trucks fit the bill after a little modification.

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The motor rests in a styrene cradle with a groove cut to allow proper worm to gear engagement then soft set in canopy glue as I’ve done with other builds. A strip of brass was attached to uprights at either end to provide weight and also a shelf for the Lokpilot decoder and TCS powerkeeper in the cab.

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I added weight to the cab with lead blocks epoxied into the cheeks of the cab below the window line. Small bulkheads were added to the cab end of the hoods and shrink tubing added to be a conduit for light wiring before filling the remaining space with tungsten powder. A styrene screed ensured the powder was at the correct depth so as not to interfere with the brass strip. So far it weighs in at a nice 28.34 grams and there’s still the tungsten filled fuel tank, brass air tanks and brass exhaust stacks to add weight. My Bachmann 44t weighs 34.88 grams for comparison.

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While the powder was drying out, I installed pickup strips from a Kato 11-106 power chassis. They are glued to the sill in the center then the wires from the the decoder were routed through holes and soldered on.

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The couplers are MT Z scale and the screw hole is far enough inboard that they will double as shell securement with a tapped styrene block glued in the outboard end of the hoods.

It still needs refinement for more robust truck securement and a small adjustment in spacing but the first test run was quite positive. Note the noise in the video is my furnace running 10 feet away and the switcher runs near dead silent.

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There’s much more to do but the heavy lifting is done.
Here’s a family photo with the 45 ton sibling.

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[peteski]

[Jim Starbuck]

I’ve fielded some questions on how I mounted the Bachmann trucks in the printed chassis. The honest answer is I don’t know yet. It’s still developing.
The stock Bachmann 44t chassis utilizes slots that capture the tabs on the trucks when the two halves are screwed together with the weight of the chassis resting from the top of the slot to the top of the truck tabs. The pad on the bottom of the cage is where the brass pickup tab on the truck makes electrical contact.

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The tab containment is crucial because all the tractive effort put forth by the driven trucks is transferred to these tabs to push the engine and whatever it’s pulling forward.

My printed shell is narrower by at least 2mm. I filed the truck tabs back to fit the inside shell dimension. Tha still leaves about .020” of the tab left. I glued .020 x .020 styrene square stock to the inside of the chassis slot which keeps the truck centered side to side but the  radius I filed in the square stock pieces aren’t adequate to keep the trucks from popping out when a load is applied.

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I’m going to refine this a bit and I came up with this. The styrene strip will still be in the chassis slot which will make up the bottom of the truck tabs slot which will keep the truck from dropping out when the engine is picked up. I’m going to glue a wafer of .030” styrene to the inside of the hood. This piece will have a three sided notch cut out of it open and flush with the bottom of the shell comprising the other sides of the truck tabs slot. With the trucks slid into the chassis from understand inboard then the shell will fit down from the top capturing the truck tabs.
It’s hard to explain but will make sense after I do it and post a photo.

[Chris333]

I have milled down a 44t frame till it was just as narrow as the motor. Don't know if that would fit for you, but it can be done.

[Jim Starbuck]

I have milled down a 44t frame till it was just as narrow as the motor. Don't know if that would fit for you, but it can be done.

Thanks Chris, that’s good to know.

[Jim Starbuck]

I have another shell with the shell and sill printed as one piece. I was intrigued by maybe fitting a Bachmann chassis under it. The stock motor is still 1mm too wide and slightly too long to fit in the cab but there may be a remotored hybrid chassis in the future. Many possibilities here.
Speaking of the Bachmann 44t, here’s a comparison photo. Though roughly the same size overall the scale hood width of the Whitcomb shows a dramatic difference.

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[dieselfan1]

Nice. Not that long ago building anything like this from scratch was rare. Now we see more and more projects like this.

[Mark5]

Speaking of the Bachmann 44t, here’s a comparison photo. Though roughly the same size overall the scale hood width of the Whitcomb shows a dramatic difference.

Yeah, Bachmann made that hood way too wide! 

(your Whitcomb is remarkable!)

Mark

[Jim Starbuck]

I’ve been procrastinating (more than usual) on building the fuel and air tanks but today I just jumped in and did it.
The fuel tank is just a built up styrene box which was filled with Liquid Gravity and capped with thin sheet.

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The tank sits on a .040 styrene wafer with .020 strips to clear and insulate the air tanks from the pickup strips.

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The air tanks are .075” brass round stock with a bit of hard to photograph detail turned into the ends on the lathe and also drilled for .0125 wire crossover piping.

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The whole assembly was glued to the bottom of the chassis with canopy glue which can be removed if I ever have to remove the trucks.

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The fuel/ air tank assembly added 1.62 grams to the total weight of the model. Even without that weight I’ve been running it on the test track pulling 11 cars and a caboose with no problems.
Next up before paint is turned brass exhaust stacks and wire railings.

[Chris333]

Your mission should you choose..

This guy has a few Whitcomb loco files:
https://www.thingiverse.com/thing:6887283
Scale them down to N and put your magic nano-motor in it 

[Jim Starbuck]

That’s extremely cool! And he has a 35 Tonner!

That two axle would be very doable with a remotored turnback drive like my GE 25 Tonner.
I’m not familiar with how Thiniverse works. Are the files just available for download?

[Chris333]

Yeah just click files and all the files will pop up for you to download separately. You probably don't need things like the horns and tiny stuff.

[Jim Starbuck]

Here’s the current state of progress.

I still need to finish the window glazing, add a horn, bell, railings, cut levers, wipers, wind deflectors, trainline hoses and lighting then weather it.
I am going to attempt t paint the tiny WHITCOMB embossed lettering on the grill white too. Wish me luck.
I modeled it from a photo in May ‘56. It was one of at least three that had the exhaust stacks moved from just ahead of the cab.
This particular number was damaged in a roundhouse fire in Freeport, IL in May of ‘57 and scrapped.

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[Jim Starbuck]

Here’s the signature grill and grab rail that undoubtedly proclaims Whitcomb.

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[peteski]

Outstanding modeling Jim!