Tender lights

[Lemosteam]

The wire insulation won't hurt in a metal application either.  THE site does not specify the wire diameter so it may be tough to get two through some tricky areas. That's what held me off.

[Mark W]

The Micro Litz is the smallest traditionally insulated wire I've worked with.  Here's a comparison between 32 gauge (I think) and .1mm copper wire (which I believe is coated).  I'd say it's about half the diameter of 32g and twice that of the copper wire, which came on the cool white LEDs from the same ebay shop.  Well, there are two, evemodels_usa and evemodels_eu, one carries the warm with litz, the other carries cool white .1mm copper (which I believe is coated). 

[Lemosteam]

Cool.  TCS has a 36 gage, seven strand wire that is 0.049" diameter. I just bought some for the PE, but it is ungodly expensive.

I found an online place, hobby kings I think, that appeared to be less per foot, but they did not have a direct number to call and ask so I bit the bullet on the TCS wire.

[C855B]

The wire insulation won't hurt in a metal application either.  THE site does not specify the wire diameter so it may be tough to get two through some tricky areas. That's what held me off.

My thought, too. The micro Litz is pretty interesting and would work well for things like headlights and ditchlights, where you can route the wires through the model. Hard to beat the price, too! Mark, are you thinking the outer diameter of the Litz is around 0.006" or so? One pair might pass down a Ngineering 0.018"OD tube, but it'd be tight and any kink or unevenness will be a showstopper.

For the Showcase Miniatures masts I'm playing with now, Ngineering's #38 magnet wire at least threads well, and there's room for several strands. Jury is still out on whether I'm going to have issues with metal-to-metal contact through unintended scrapes of the enamel insulation. Soldering #38 to 0402 and 0404 chips is pretty intense; I can only do a few at a time before having to break away from it.

[peteski]

Jury is still out on whether I'm going to have issues with metal-to-metal contact through unintended scrapes of the enamel insulation.

I used to worry about that too, but I have never had any problems with enamel-coated magnet wire.  After all, in its intended use it is surrounded by more (metal) magnet wire (in a transformer winding).  Scrapes could be a problem if one is not careful. But in the type of subminiature work the wire is used in, one is already very careful . 

I ordered 20 of the warm white LEDs with that insulated wire. When I get them I'll take some measurements and photos comparing that wire to other types of wire I have.

What I have used for signal wiring in the past is a very fine insulated silver wire sold as ignition wire for automotive scale models (to "wire up" their engines). There are several sources and the thinners diameter (including insulation) is 0.007".  It comes in multiple colors.  Detail Master is one of the suppliers.  Of course it is relatively expensive.

[C855B]

...Detail Master...

Thanks for the lead (ooh... a pun! ). I like the idea of multiple colors, but #38 is 0.003", so the easiest source at the moment is the red/green pair from Ngineering. I am hoping beyond hope that by the time I'm done with this project I can get a triple-head signal on the Showcase mast, which is 0.034"OD/0.024"ID. Depending on what the final version will be, it'll be anywhere from 6 to 12 wires down the mast. Six will be easy, I have my doubts about twelve.

Thinking this through, I should get some of the Ngineering 0.032" thin-wall (.0025") and see if it's possible to replace the Showcase mast where the base cabinet has been cast on. This could make the difference.

[peteski]

Thinking this through, I should get some of the Ngineering 0.032" thin-wall (.0025") and see if it's possible to replace the Showcase mast where the base cabinet has been cast on. This could make the difference.

Small Parts Inc. was my one stop shop for a huge selection of hypodermic tubing. They were easy do deal with and their catalog was very easy to look through and to find what I needed. They stocked standard, thin and extra thin wall tubing. But since Amazon took them over and "improved" their website, I haven't been able to find anything without lots of frustration.  I haven't actually bought anything from them since the Amazon takeover.   

You might also want to try Special Shapes (now division of K&S) for thin wall brass tubing. It is easier to solder than stainless.

[C855B]

Oh, I have Special Shapes bookmarked. In looking at their brass selections versus what I have, I'm now moderately confident that Showcase is using their 1/32" 0.006"-wall tubing. Let me see if I can wade through what Amazon did with Small Parts. I was familiar with them before the takeover. Ngineering makes it easy, tho', and I have no issue with paying a little extra for the legwork.

Also, I have no qualms with reaming-out the existing tubing. I've done that before, it just takes time and patience... and a healthy stash of tiny drills.

[Mark W]

...Depending on what the final version will be, it'll be anywhere from 6 to 12 wires down the mast. Six will be easy, I have my doubts about twelve....

Getting off the original topic, but I'd definitely do common cathode, using the mast as the ground and only feeding 6 wires. 

[C855B]

Getting off the original topic, but I'd definitely do common cathode, using the mast as the ground and only feeding 6 wires.

That's sort of why I said anything from 6 to 12. Common cathode is a slight (tho' not impossible) challenge in the context of the Showcase signals - it's going to be difficult to make one of the LED leads contact the structure without compromising insulation protecting the other connections. Plus the heads depend on glue for attaching to the brackets, so this system would have to be modified to ensure metal-to-metal contact. If I were to do a R/G arrangement as you seem to suggest, it would likely be with a back-to-back pair of 0402 LEDs doing the old-school system of reversing polarity for indication with some form of AC for yellow. Those would then benefit from a non-commoned structure, with only two leads per head.

I would seriously try to make common cathode work if I were doing separate R/Y/G, although I have a circuit concept that would make that also work with isolated wiring and a tricky polarity reversal scheme.

I've been resisting starting a thread on this because I don't think I'm far enough along in the actual process. Maybe later this evening.

[peteski]

In my experience common anode is easier to drive electrically than common cathode.  I bet that is why DCC decoder functions use common anode too.  Open collector transistor circuit is really simple to implement.

[C855B]

Welllll... in this wiring discussion we're just trying to common something, not relevant yet whether it's anode or cathode. The end game will likely will be common anode since there's more off-the-shelf support for it.

[TVRR]

All this talk of lighting options has made me think it may be time to do the caboose of my dreams- Dim interior light, R/G marker lights, and a detailed interior. Replacement etched brass end railings and ladders, a guy could go berserk in a 2 inch space. The marker lights would be crucial, somewhere I've seen them- anyone know?

[Joetrain59]

Try Richmond Controls.