Installing LED's in a DCC converted Atlas Alco C-424

[Capt.Brigg]

I am currently converting an Atlas Alco C-424 to DCC and have run into a problem with converting the cab and rear light systems into LED's. You can see the two long plastic light tubes used in the factory setup with one light bulb for both. Since the Soundtraxx MC2 board has separate light controls I want to incorporate two LED's, but where and how to add them. Any suggestions are warmly welcome.

Capt. Brigg CEO
Pacific Cascade Railway in HO gauge
Route of the Northern Star

[AlienKing]

I cut the light pipes just after the point where they attached to the roof support, so there was a 1 inch gap.  Since I was doing a light board replacement, I opted to solder the LEDS directly to the light board and bend them so they lined up correctly.  If you are using the MC2H104AT light board replacement, you could do the same.

If you are using one of the wired decoders, like the MC2H104P9, you could hot glue the LED's to the top of the shell where they line up.  However, this sometimes makes getting the shells back in place a bit tricky, since you need to leave enough extra wire to safely remove the shell later.

Here's a link to a blog post I wrote when I did my C-424s.

http://model-railroad-hobbyist.com/node/474

[Capt.Brigg]

Alien, thank you for your reply. The problem I am concerned with is after cutting the ends off the plastic light tubes, how do you polish the ends so the light from the LED's enters the tubes clearly.

[fa-1]

Capt Brigg I did an atlas/kato c-425 iused a fine file and sandpaper to smooth the lite bar.  then i attached a small piece of styrene tube [id so led will fit inside] to the lite bar with CA cement. i held the LED in the tube with clear Goop or silicone caulk,it worked fine. i just did an RS-3 and used surface mount LED's. just glued them to the cut lite bar[no tube] with CA. don't forget to paint the litebar black to stop light leaks.             good luck   FA-1    modeling the NEW  HAVEN RR

[hon30critter]

Hi Capt.Brigg:

I use epoxy glue to fill in the gap between the LED and the light tube. In the past I have eliminated as much of the light tube as possible and simply glued the LEDs to the back of the lenses using the epoxy. Doing that can create some challenges in that the LEDs can produce too much light. For headlights it isn't a problem, but for number boards you need to use larger resistors to reduce the light to acceptable levels. I can't recommend a specific resistor value, each situation is different, but I would experiment with resistors in the 2200 ohm to 10,000 ohm range, or maybe higher.

Regards,

Dave

[rrinker]

 I've done the same with tlas/Kato RS-3's. I did not special polishing of the cut end of the plastic light pipe, just 'attached' the LED to the end with some heat shrink (although future ones I will probably glue). Plenty of light comes out the headlight lenses.

                   --Randy