Hello, I recently purchased an HO Canadian National Athearn Rotary snowplow with tender.
The rotary blade works on DC only, I want to install a Digitrax DH 126 D decoder so I can control the speed of the blade and also being able to turn it off. I also want to install a working sunbeam headlight.
What would you recommend, for the sunbeam itself and also the bulb.
Thank you.
Any brand of DCC decoder would work as well as Digitrax, so you don’t necessarily have to use Digitrax. For the Sunbeam Headlight, I’d use an LED instead of incandescent bulb.
Hello Cacole, thank you for your suggestion regarding the LED light.
Which type or model of “Sunbeam” receptacle would you recommend so I can instal an LED inside.
Thank you.
One of the usual suspects - Details West or Detail Associates - likely has a Sunbeam headlight casting
–Randy
Hello Randy, thanks for the infos,I’ll be looking into it.
Serge:
I’m not sure what experience you have with LEDs but here are a few hints:
Don’t forget that you will need to add a 1K ohm resistor in series with the LED for most decoder installations.
The easiest LED to fit into a free standing headlight casting will be an SMD 0603 (Surface Mount Device .060" x .030".) You can get them pre-wired:
http://www.ulrichmodels.biz/servlet/the-350/Miniature-Surface-Mount-LEDs/Detail
In this case I believe you will still have to add in a resistor but that can go inside the plow.
LEDs are polarity sensitive. For most decoders, positive goes to the blue lead and negative to the white lead.
I make lenses using epoxy.
Dave
Hello Dave, thank you so much for all the detailed infos; they are greatly appreciated.
Like HOn30 critter, I pay a lot of attention to headlights. I use the same nearly microscopic SMD LED. I next put the sunbeam fixture, with a suitable tiny hole drilled through it, in a small vise as if shining at the ceiling. I now feed the hair fine LED wires through the tiny hole with the LED carefully facing up from the rear of the reflector.
Important!! Make sure your LED works! Power it up in this loose and free state. in the housing.
I mix up a tiny bit of epoxy on a small metal plate. I then warm the plate over a flame, very gently, and the mixed epoxy runs like water. Quickly, I use a needle to dip the epoxy into the reflector area. This may take several dippings. The reflector fills and forms a natural convex meniscus or lens as you carefully and slightly over fill the bowl. Do not overfill and you will have a flat glass look or a slight concavity. All look and work great.
Note* make sure that you tape off the hole and wires or the watery epoxy will run out of the back of the light.
Once done and the epoxy cured, test again, then mount the light.
Makes for a nice looking light with lens and the LED is set in stone, so to speak.
LED goes bad? Just gently heat the sunbeam headlight with a torch after removing it. Let the epoxy burn off and the wires should come free easily. You might chase the hole out again with the same drill. Polish the lamp interior and repeat above.
I have never had an LED go bad. However, I learned the hard way to test your LED at every step prior to epoxy and curing. Really nasty to go to all this trouble and find out the wires came off the LED or the LED is bad from the get go. That is how I found out how to replace a bad led in the previous paragraph!
Hello Richard, thank you for the very detailed infos, they are greatly appreciated and will come very handy when I start this project.
Richard:
I use a needle to put the epoxy in place as well, but I didn’t know that the epoxy could be heated to make it flow better. Thanks for the tip.
The needle I use has been inserted into a wooden handle. It makes the needle easier to handle and I can put it down without the epoxy coming into contact with my work mat. After a few uses I use a small file to remove the built up epoxy from the tip:
Yes, its rather crude, and the handle has doubled for a soldering pad a few times, but it works quite well.
Dave
Serge:
One other tip that I would offer is to apply power to the LED before the epoxy has set. That allows you to see where the LED is directing its light so you can adjust the position if need be to get the light where you want it.
Also, you don’t have to put all the epoxy in at once. It is easier to get the LED glued into the right position with a bit of epoxy, and then once that has set you can fill out the rest of the lense. If you get bubbles you can tease them out with the needle.
Dave
Hello Richard and Dave, thank so much for your inputs on this post they are very informative.
Hello Dave, I did a little research on ebay and I found the LED you mentionned in your reply but before buying it I just want to make sure it’s the right thing.
Here’s the description of the item: Size: It’s 0603 SMD Led The wire about 20cm(L).
Forward voltage:3V AC or DC Compatible.
Forward current (typ/max): 15mA/20mA.
Light Color: White
What do you think?
Thanks
Hi Serge:
A couple of points.
Apparently the LEDs that you found are not polarity sensitive, but I would test them prior to installation anyhow. Use 12 volts but make sure you attach the 1000 ohm resistor before you test. It doesn’t matter which lead the resistor goes on.
I would test the LED again after it is mounted in the headlight but before you fill in the lense.
This is important: You want a ‘warm white’ LED, not just ‘white’. A standard ‘white’ LED is actually quite blue in colour and is not a good representation of a locomotive headlight. Sometimes the ‘warm white’ LEDs are referred to as ‘golden white’. Note that ‘sunny white’ LEDs are whiter in colour and are intended for modern locomotives. If you can’t find warm white prewired 0603 LEDs you can adjust the colour by giving them a couple of coats of clear yellow paint by Tamiya.
Here are some listings for warm white 0603 prewired LEDs:
Hope that helps.
Dave
Hello Dave, every bit of infos helps, thank you for your feedback and suggestions,they are greatly appreciated. I’ll take a look at the list you supplied.