This is more or less just some random thoughts about N scale "Tunnel Motor" models. Did I hear the rear intakes on the I.M. models will have the see-thru effect obscured entirely by the frame? This is understandable if true, as this would be probably next to impossible to achieve entirely if the rear truck is to be powered. On a kitbash I did, where I used a Kato SD40-2 frame, I was able to cut away enough frame so that the see thru effect could be achieved (for 1/2 of the grille length anyway). Cutting back any farther would have gotten into the area where the rear trucks and worm gear seat into the frame. Perhaps this might also be an option with the I.M. models, should the modeler want this effect...even if it is only partially effective. Thoughts? Here's a shot of my kitbashed unit's rear grilles. Notice the rear half of the grille is see thru... Russ
I bet that a handy guy could grind out a notch on the frame halves just behind the grills and have at least some light show thru. What do you think?
The see-through grilles on tunnel motors is so obvious it is worth trying to achieve on a model. If run in a multiple unit lash up, the rear truck could be unpowered, which could allow the rear frame to be cut well down. Would anyone do this, I wonder?
I agree, Alan, that the see-thru effect is almost "mandatory"! I've also pondered the idea of turning the rear truck into an unpowered dummy truck...thus removing all of the gears, frame and everything that would be visible behind the grilles. I would imagine that this truck could still be used for power pick-up though. Although it would take a serious math wiz to figure it out, I think that unpowering one truck may have a drawback of reducing power even MORE than the obvious 50% (the obvious 50% coming solely from the loss of tractive effort from 1 truck). The rear truck would then also become a new source of drag that was not there before (even if it is free-rolling) and the loss of frame would reduce overall weight of the loco (perhaps effecting even the front truck). I wonder if these added drawabacks might cause the modified loco to be almost useless unless permanently assigned to a lashup . Russ
Russ,to my way of thinking your on the right track(no pun intended ).I think I would do as you say but only open the frame up behind the grilles leaving the rest of the frame there.There are some very tiny roller bearings available and I think if all else failed you could mount these on the rear truck axles to make them extremely free wheeling.(I want to try this on a Bachmann AMFLEET coach).
