Bachmann GE 70 Tonner with Loksound Nano

[Jim Starbuck]

The Bachmann 70 Tonner is another fine running locomotive that greatly benefits a high quality decoder.
I was looking through the ESU sound library and came across the Cooper Bessemer 6-FW-6-LT in the GE 70 tonner.
It’s file number S0786.
I really liked the sound file so decided to try this project using a Loksound 58923 Nano decoder, an Iowa Scaled Engineering Run-N-Smooth powerkeeper and an 8x12 Soberton speaker.

I knew the frame would have to be milled so I weighed the stock engine before starting. It came in at 32.37 grams.
The chassis is very similar to the 44 Tonner as the two share the same motor and trucks and this install is similar.

The decoder resides at the front of the frame.
There’s already a pocket in one of the frame halves so I milled the rest to the same depth as the bottom of the pocket.
A minimal amount of material actually has to be removed.

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The cut at the cab end is for the powerkeeper. The cut is only .8mm deep and starts at the raised part of the chassis. If I did another one I would mill about a millimeter forward into the raised part to give just a bit more forward clearance for the speaker.

Holes were drilled and tapped for 00/90 brass screws for attachment points for track pickup.

The chassis was filed at an angle a bit at the top front of the raised motor opening to let the decoder nest down a bit better. I removed the unused function wires from the adapter board then carefully routed the wires so there was only a single thickness of wire coming off the board.

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The  motor leads were connected then the decoder was taped down with kapton tape.
The powerkeeper is held down by thin two sided tape.

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The track pickup wires are routed under the left side of the powerkeeper board leaving room for the speaker wires on the top side.

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Because of the way the sill is made, it won’t fit down over the speaker enclosure so the hood goes on first with the speaker mounted to the top of the chassis with two sided tape.
Lights are 0402 LEDs with magnet wire taped to the roof of the shell. 3k 1/8 watt SMD resistors are soldered in line for white and yellow wires connected to the cathode side with the anode side of each connected at the positive common at the powerkeeper. There is a GND pad on the decoder adapter board which I soldered a green wire to. This connects to the ground side of the powerkeeper.

The speaker uses a homemade styrene enclosure. The wires were connected then the cab slid down over the top and latched to the sill.

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The engine is fitted with Z scale couplers and decaled for an Iowa short line.
When totally finished I weighed it again and it came in at 32.38 grams so it still pulls well but now runs much better with a high quality decoder.

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Edit:  Added a shaky video.

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[MK]

Wow!   

[peteski]

As usual, well done Jim! 

[wcfn100]

What's the story on the paint job?


Jason

[Jim Starbuck]

What's the story on the paint job?


Jason

That’s a stock Bachmann paint scheme for one of their unlettered versions. I don’t know where they came up with it.
Turns out it’s close enough for the Fort Dodge Des Moines and also the Des Moines and Central Iowa so I made my own lettering for it.
I’m guessing it may have originally been a demo paint scheme from GE and the short line just stayed with it and lettered their units.

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[kiwi_al]

So you've done the 44 tonner and the 70 tonner, how about putting Loksound in a GE 25 tonner?  . You are getting way too good at these installs 

[Jim Starbuck]

Thanks guys!

[carlso]

 You are a true master Jim.

[tehachapifan]

Another great install!

[peteski]

So you've done the 44 tonner and the 70 tonner, how about putting Loksound in a GE 25 tonner?  . You are getting way too good at these installs 

I think for a 25 tonner Jim would have to scratchbuild the loco (I never seen a ready-to-run, commercially available 25 tonner in N scale). 

I should also add that with Jim, that scenario is entirely possible!

[kiwi_al]

I think for a 25 tonner Jim would have to scratchbuild the loco (I never seen a 25 tonner in N scale). 

I shoudl also add that with Jim, that scenario is entirely possible!

https://www.shapeways.com/product/P8M2A2M6J/n-scale-ge-25-tonner-non-powered?optionId=57166059&li=marketplace

BTW I didn't say it was going to be easy

[Jim Starbuck]

I think for a 25 tonner Jim would have to scratchbuild the loco (I never seen a 25 tonner in N scale). 

I shoudl also add that with Jim, that scenario is entirely possible!

@randgust scratch built this one a few years ago.

[peteski]

LOL, should have been more specific.  Fixed  my post.

I also suspect that at some point, when the model gets small and light enough, the DCC sound operation (even with whatever maximum size keep-alive can be fit in it) will not run reliably on anything less than absolutely perfect track.

[garethashenden]

I got through most of the same installation but couldn't get the shell to fit afterwards. a bit more milling and rearranging the wires should fix it.

GE had some "standard" paint schemes. The orange and cream is one of them. The St Johnsbury & Lamoille County in Vermont had 70 Tonners in this scheme, and I've seen pictures of a shortline in the south, Alabama perhaps, I'm not sure, that had more 70 Tonners with the same paint. It was cleaver of GE. They can paint the engines all the same and just change the lettering as the customer demanded.

EMD sort of had standard paint schemes as well, just compare Rio Grande and Boston & Maine F units. The paint schemes were clearly designed by the same person.

[Jim Starbuck]

I got through most of the same installation but couldn't get the shell to fit afterwards. a bit more milling and rearranging the wires should fix it.

GE had some "standard" paint schemes. The orange and cream is one of them. The St Johnsbury & Lamoille County in Vermont had 70 Tonners in this scheme, and I've seen pictures of a shortline in the south, Alabama perhaps, I'm not sure, that had more 70 Tonners with the same paint. It was cleaver of GE. They can paint the engines all the same and just change the lettering as the customer demanded.

EMD sort of had standard paint schemes as well, just compare Rio Grande and Boston & Maine F units. The paint schemes were clearly designed by the same person.

Thanks for the information on the paint scheme.

I’ve found with the Nanos it’s important to desolder the unused function wires and carefully route the wires so they exit the adapter board in a single layer especially in an already tight install like this.