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NW Modeling List nw-modeling-list at
Thu Apr 18 13:16:09 EDT 2019

I built the attached Excel spreadsheet in the hopes that multiple RRs would have had Mastodon classes that were close to N&W's, under the theory that NWHS could join forces with the societies of other RRs to lobby for at least a common frame/running gear that could support many RTR models.  And at this point, I want to acknowledge for its extraordinary database and resolve to keep it available on-line for all to access.  Truly a tour de force!

I don't come away very optimistic, viewed from my knothole, but for those modelers who can accept some inaccuracies in a model to get a "decently close" RTR version, the results may be a bit more encouraging.  If a suitable "common standard" frame and mechanism can be agreed on, then each society could work with a builder toward a superstructure acceptable to that society, while using the "common standard" chassis.  Alternatively, members of various societies might work together to crowd-source 3D-printed superstructures made to mate with a "common standard" frame.  (IMO, this should be done for all USRA designs, and it would be equally possible to develop "plain vanilla" USRA superstructure CAD models from which all idiosyncratic models for specific RRs could be modified.  If these resources could be brought into existence, then we'd have a strong interest in getting BLI to sell their several existing USRA chassis, with motors, DC/DCC/Sound parts included, but no tender or loco superstructure.)

I'll admit that I'm not willing to compromise much on driver wheelbase:  maybe +/- a percent.  I'm also not willing to compromise more than an inch on driver diameter or piston stroke, and not at all about valve gear type-and I prefer my Stephenson-equipped models to have the axle cams and valve drive rods included in the model.  (Hey, if PFM could do this on their Shay models as early as 1959, I don't think I'm asking for too much here!  That said, it really differentiates N&W M's from M-1's, which is an issue for all of us.)  I'm more forgiving on overall engine wheelbase, because that can be altered within my abilities to accomplish the work.  Everybody gets to vote on these tolerances and features with their own wallets and time allocations.

On the spreadsheet, I first identified the N&W M, M-1, and M-2 parameters, and then compared all the other RR twelve wheeler classes, and highlighted the ones that were "close" by my standards.  You can do the same, changing the color coding in the spreadsheet to suit your tolerances.

My conclusion is that there might be basis for collaboration with the societies interested in CE&I, MP, NP, UP, and Winston-Salem Southbound, mostly for matches to N&W's M and M-1 classes, although the UP TW-57 class looks close to be a fair match to a Baldwin N&W M-2.  At a slightly bigger stretch, BR&P and SP, D&IR, and GN societies might be brought into the tent.  Your own tolerances may suggest opportunity for broader collaborations between NWHS and other societies on such a project.

Realistically, the only model producer whose current business model could make much use of a "common standard" chassis is BLI-and only because they might be able to justify making 4 to 8 very different superstructures for a single "common standard" chassis under their "hybrid brass" line.  I doubt that any company would invest in superstructure injection molding dies for classes that had fewer than 10 locos in them, or for BR&P, Laurel & Tullahoma Western, or Winston-Salem Southbound prototypes.  That said, I acknowledge the existence of MTH triplexes (of the Good and Not Good livery types that perfectly illustrate how not-so-far one model company is willing to go in speciating chassis for different RRs.)

So, IMO, rational people should expect the products of this thinking to have an MSRP of $600 (for a "medium" sized BLI brass hybrid model)-which is not more affordable than any Sunset M, M-1, or M-2 on eBay in current times, but would include a robust drive with DC/DCC/Sound).  While I don't think much of the early BLI hybrids (UP TTT, NYC Mohawk), they have since produced some really nice ones (NH I-4 and I-5, T&P I-1, GN S-2, UP 4-12-2, C&O J-3a; I'm indifferent to the C&O L-1 because of its finish, and haven't held a PRR S-2.)  I'd buy a BLI hybrid M-1 and/or M-2, if produced well, over a Sunset or LMB version.  And I'd definitely buy a BLI hybrid SP TW-8 over a Westside or Max Gray TW-8.  But I'll hang onto my PSC CNJ K-1s, my PFM GN G-3, and my PFM NP X, all of which are very nice models, even though it will cost me $600 each to have the latter two painted and DCC'd.

If a society could get members interested in crowd-sourcing CAD models of their superstructures of interest, I'd WAG that the 3D printing costs might be ~$200 for a decently detailed superstructure kit.  Adding $250 for a "common standard" BLI chassis w/DC/DCC/Sound plus $350 - $400 for custom painting would put this approach at much higher cost than a BLI hybrid, but some modelers can throw their own really nice paint, giving them a potential ~$450 model plus assembly and painting time investment choice.

-Eric Bott

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