IM SD40-2 Ditch Lighting

[peteski]

My main point was about sharp bends...which the C44-9W does not have.

Agreed!  Gently curved light conduit works the best.

[AKNscale]

It also doesn't help that they're using yellow LEDs either.

[jagged ben]

The Kato 'Mid-Production' SD40-2 is notable for precisely the fact that they came up with a whole new revolutionary screwless frame design precisely in order to make space for the light tubes to sweep more gently to the ditch lights. 

As I mentioned in the other thread, the IM SD40-2 is only the second production model to feature ditchlights on a spartan cab.  (Well, there's the FVM GP60 which arrived weeks earlier, but I guess they realized the ditchlights were so disappointing they decided not to advertise them as functioning.  Similar mistake.) 

[peteski]

The Kato 'Mid-Production' SD40-2 is notable for precisely the fact that they came up with a whole new revolutionary screwless frame design precisely in order to make space for the light tubes to sweep more gently to the ditch lights. 

Are you just speculating as to the reason or do you know that as a fact (not an alternate fact)?    either way, that's interesting.

I always thought that the next generation (screw-less) mechanism was simply Japanese engineers trying to outdo themselves.  It usually includes the sprung center axle (on 3-axle trucks), shock-absorbing pickup strips, and finer pitch gears/worm with the worm being part of the truck (not the chassis).   While it is a very clever and advanced design, the screw-less chassis is a pain to deal with. Also,the super-smooth-running delicate mechanism can easily get jammed by small debris, and is often damaged by ham-fisted modelers.  While I applaud that design, I think that as far as the general modeling public goes, they went too far and made the model too fragile.

[tehachapifan]

Are you just speculating as to the reason or do you know that as a fact (not an alternate fact)?    either way, that's interesting.

I always thought that the next generation (screw-less) mechanism was simply Japanese engineers trying to outdo themselves.  It usually includes the sprung center axle (on 3-axle trucks), shock-absorbing pickup strips, and finer pitch gears/worm with the worm being part of the truck (not the chassis).   While it is a very clever and advanced design, the screw-less chassis is a pain to deal with. Also,the super-smooth-running delicate mechanism can easily get jammed by small debris, and is often damaged by ham-fisted modelers.  While I applaud that design, I think that as far as the general modeling public goes, they went too far and made the model too fragile.

Agreed. Trying to keep an NW2 drive held together long enough to get the shell back on is like stacking marbles!

[jdcolombo]

Another way to do the ditch lights:

[ Guests cannot view attachments ]

You can cut the light pipes on the flat part of the shell, and glue a 603-sized LED to the pipe at the cut (I used a dab of CA to glue the LED in place).  The shell will fit fine (I checked) after doing this.  I then put a bit of black electrical tape over the joint, and painted the rest of the light pipe flat black. 

John C.

[peteski]

The best way to get bright ditch and head lights is to place the LED directly in the housing behind the lens opening ( like @craigolio1 does).

[mu26aeh]

I'm wondering if I can get that Atlas board in a similar spot John C.  The led's on the board are about .3 mm apart, would probably have to mill out a part of the frame to allow shell to sit back down.  Also have to figure out where I would solder wires to.

Smh, still have to wonder why didn't ESU/IMRC do this to begin with so we didn't have to.  They never did respond to my message thru their FB page.

[peteski]

Smh, still have to wonder why didn't ESU/IMRC do this to begin with so we didn't have to.  They never did respond to my message thru their FB page.

I suspect that the design is done this way for simplicity. All the electronics and LEDs are contained on the decoder, so there are no wires to run and circuit boards to mount in the shell. It is cheaper and simpler to make (lower labor cost).  Remember, every wire has to be soldered and every peice has to be assembled - this is all reflected in the man-hours needed to assemble the model.  Even the decoder has no motor or speaker wires soldered to it (for the same reasons).

[jdcolombo]

The best way to get bright ditch and head lights is to place the LED directly in the housing behind the lens opening ( like @craigolio1 does).

Yep, but I didn't want to try to disassemble the shell to do this.  Actually, you could probably glue a 603 LED to the existing light pipe right where it first curves down into the shell; then it you would only have a straight piece of fiber optic to the actual light.

One of the problems with the IM implementation is that the ends of the fiber optic where they terminate at the ditch light housing are not polished (at least not on mine) - very rough, and there may even be some glue on them.  This scatters light, and I've gotten a bit more brightness by scraping the ends of those with a hobby knife. 

As you note in your other post, Peteski, I'm sure all this was done to maximize assembly efficiency.  There is no hand-soldering on this unit anywhere, not even the speaker, which is designed so that the spring clips on the back contact the silver metal bands that then wrap around the motor to the top of the frame, where they contact pads on the back side of the decoder board.  The problem is that in this case, there's a tradeoff between efficiency and quality of end result.  But IM probably made the right call - probably not many folks interested in paying $250 street for a diesel loco with sound.  For those that want better, well, there's TRW where the crazy people who take 'em apart and hand-wire LEDs or replace speakers hang out.

John C.

[jagged ben]

Are you just speculating as to the reason or do you know that as a fact (not an alternate fact)?    either way, that's interesting.

I would have said it was a reasonable supposition simply based on observing the design.  But I suppose it's possible they got lucky.  Another motivation for making space in the nose was the Santa Fe nose lights, so maybe it just sort of came out that way.  They've had some bone headed ideas too, like the amber colored light pipes with blue white LEDs that cameout looking like yellow LEDs.

Maybe when Kato first did the C44-9W they put a lot of effort into it because they didn't know if it would even work, whereas the other manufacturers have come up with crude copies because they didn't realize how hard it was.  But that is speculation.

[AKNscale]

Good to know that it fits John, thank you. Now I know that my second LED will be much easier. And like you, I did sand the end of the light pipes as I didn't like how rough they were.

Just FYI, as long as you're careful, the shell isn't too bad to disassemble. Also, conveniently enough, the body clips tightly back together making the glue pointless.

[craigolio1]

The best way to get bright ditch and head lights is to place the LED directly in the housing behind the lens opening ( like @craigolio1 does).

I cast mine right into the ditch light housing.

This is a Kato Mid-pro with the ditch lights moved to the pilot.







And a kitbashed CRS20 (RS18) which has four individual ditch light LEDs at each end. Can't do that with fibers because of all the bends.



It's a pain but it allows me total control over brightness and colour, and there are no alignment issues.

Craig