IM SD40-2 Tweak - Adding Under Frame Detail

[cbroughton67]

So, while I'm pretty happy with the new Intermountain SD40-2's overall, they appear to me to sit too high. After comparing them nose-to-nose to a Kato SD40-2, I realized that their height wasn't the issue. It was the under frame, which is modeled on the Kato SD40-2, but not the IM version. The open space between the walkways and trucks creates the illusion that the locomotive sits higher than it actually does, not to mention that it's not prototypical. So, a grabbed some 0.060" styrene channel, made some measurements, and added an under frame of my own. I think this small detail makes a big difference in the appearance of IM's SD40-2.


I marked the position of the fuel tank and pickups to measure the length of the channel, and where to locate it when gluing.
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Cut the channel to length. I created a "notch" for the bell using a round jeweler's file.
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Before adding the under frame
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After adding the under frame
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Comparison
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[mu26aeh]

Excellent and simple !

[chessie system fan]

Looks good!  I did this to an SD50 a few years ago.  If Kato can do underframes on every model these past ten years why can't everyone else?

[Santa Fe Guy]

Perfect fix. A good friend and I were looking at the same issue and will definitely do ours.
They run well and sound even better so this will make them look like they should.
Thanks for the reminder as I recall a similar fix done to the first run many years ago in N Scale Railroading.
Rod.

[Ed Kapuscinski]

Very nice!
I did the same thing on an LL C424 and it made a TON of difference there too.

[Catt]

Every time I look at the before picture it reminds me of my old Bachmann SD40-2.Thatthing did not run more than a foot at a time and looked like it had a suspension lift kit under it.I solved both the high rider look and the crappy running by putting the shell on a KATO SD45 chassis.I also filled the pilots and body mounted MTL 1015's.

That old Bachmann sure surprised a lot of folks at train shows.People would ask if it was a Bachmann and of course I always said yes,but did not tell them it was on a KATO chassis. 

[Santa Fe Guy]

I too had a couple of Bachmann SD40-2's and modified them as shown in a very early article in Jim Fitzgerald N scale newsletter. They turned out great, nice and low and ran for years long before Kato arrived on the scene.
Rod.

[High Hood]

Hey Chris, could you please put up a picture comparing the updated Intermoutains vs a Kato -2?

[Ed Kapuscinski]

As I was driving yesterday I realized this might be a great 3D printed detail: something that included the frame, the bell, the air dryers, etc... @Lemosteam?

[Chris7092]

Very nice observation and thanks for sharing the quick fix.

I've been eyeing some IM SD40-2's; I'll keep this in mind once I pick one up.

Chris Wehman
Ringgold, GA

[cbroughton67]

As I was driving yesterday I realized this might be a great 3D printed detail: something that included the frame, the bell, the air dryers, etc... @Lemosteam?

I was thinking the same thing, Ed, but wondered if FUD would be too brittle. @Lemosteam - Don't I remember some sort of speaker baffle /fuel tank modification you designed for the IM SD40-2? You could kill two birds with one stone!

Chris

[ednadolski]

As I was driving yesterday I realized this might be a great 3D printed detail: something that included the frame, the bell, the air dryers, etc... @Lemosteam?

Just a thought, perhaps etched phosphor bronze might have some potential (with the smaller parts as glue-ons).  A clever design could perhaps also work in the electrical pickups.

Ed

[peteski]

Just a thought, perhaps etched phosphor bronze might have some potential (with the smaller parts as glue-ons).  A clever design could perhaps also work in the electrical pickups.

Ed

Um, as long as it is made in separate left and right halves. 

[gbcaboose]

Just to be sure before I try this, it looks like the added styrene pieces need to be placed on the outer most edge of the sill so not to interfere with the contact strips. I'm assuming the added pieces won't hinder the trucks on curves or turnouts. Here's some approximate markings with my main concern being the spacing (inner or outer) on the sill. I'll measure for the correct length. I think I'll try it on an older Atlas 420 first as those have a similar gap between the shell and the truck. Any thoughts?



Thanks, Mike

[MK]

Use Elmer's Glue or the like, something that doesn't bond permanently to plastic, to test out placement.