SD40, SD45 and U30C / C30-7 models

[scaro]

Gday, am wondering if there is anything I should know before buying an N gage C-C loco with 40' between truck centres (or thereabouts) for scratchbuilding.

Katos seem to be cheap if you get an old one, but they are kind of new territory for me.

I need something for TT scale which in N ought ideally to be 40'6". Now I know SD40/45 are 40' whereas U30C etc ought to be 40'11".

Don't know whether N manufacturers worried about the 11", but the Spookshow shows these chassis to be fairly different ie, they didn't just stick an SD45 chassis under their U30C etc

I guess with Kato that they are going to be fairly accurate? Even the old Spectrum SD45 I have is the correct 40' between truck centres, but I've read various things about pickup on these being iffy.

From diagrams of the prototype and the old HOSAM site, I recall the GEs had asymmetrical trucks but only by a few inches. Don't know whether this is reflected in Kato models.

I don't have an interest in DCC or sound.  (The mechs I have used in the past had no problems making noise.)

[kiwi_al]

So are you putting a TT scale shell (scratch / kitbashed) onto an n scale mechanism? A bit like NZ120?

[scaro]

Yeah, same principle. Loco that could be done with SD40/45 or possibly GE U30C/C30-7 chassis is the Western Australian RA class, a big English Electric. (Simon Barber photo attached.)

[kiwi_al]

The only issue I can see is that Kato normally make their shells wider than the prototype but looking at the RA Class you'll probably be right.
The SD45 should be close to 40' and the U30C truck centres according to dieselshop are 41'11" so you have a choice! 

[learmoia]

As I recall..
The Kato drive on the SD series of locomotives (I think including the U30C and C30-7 are all the same basic design)

The correct truck spacing was achieved by designing different truck frames that have offset gear towers to give correct truck spacing when assembled.

An early example of this, you could take a Kato C30-7 drive, flip the trucks 180 degrees on both ends, and have a (close to) correct truck spacing to re-power a Bachmann C40-8.

[scaro]

the U30C truck centres according to dieselshop are 41'11" so you have a choice! 

HOSAM (the late S.A. McCall) gave that dimension on his site too, but the PRR drawing and one other say 40'11". So not sure.