Layout Short - Update

[sschnabl]

That's a good question.  I'm only familiar with their PCB ties.  Are PCB ties from other manufacturers the same way?  Or do they have some sort of non-conductive material on the back side?

[rodsup9000]

 As far as I know, the .030" thick is only made as a 2 sided PC board

[davefoxx]

What I do with oversized feeder wires is, after stripping the wire end but before twisting the strands, bend about half of the wire strands over ninety degrees and cut them off even with the insulation.  The remaining (fewer) strands are twisted, tinned, and soldered to the rail.  Easily reduces the visible feeder without significantly compromising resistance.

DFF

[garethashenden]

As far as I know, the .030" thick is only made as a 2 sided PC board

Single sided copper clad pcb is readily available all over the place. It is less common than double sided, but it is absolutely available.

That's a good question.  I'm only familiar with their PCB ties.  Are PCB ties from other manufacturers the same way?  Or do they have some sort of non-conductive material on the back side?

These ones are single sided: https://voltscooter.com/product/n-scale-pcb-turnout-ties/

[rodsup9000]

Single sided copper clad pcb is readily available all over the place. It is less common than double sided, but it is absolutely available.

OK thanks for the link and letting me know I just know that 20 years ago, all I could ever find was double sided via the internet.

[robert3985]

Hi Bob still having a hard time figuring out how the broken rail caused the short on the bottom of the ties?

...Sumner

Sumner, the story about the broken point rail was used to show my bad experience with not checking for shorts before starting my re-wiring project on my layout's sections/modules.  I learned to gap both sides of my PCB ties when learning how to build my second-ever turnout...well before I was happy with my work and before I had good enough ones to actually use on my NTRAK modules.

So, there isn't any connection between PCB tie gapping and the broken point rail.

Cheerio!
Bob Gilmore

[Sumner]

..So, there isn't any connection between PCB tie gapping and the broken point rail. Cheerio!  Bob Gilmore

Thanks, and also thanks for mentioning the Superior #30 some years back in one of your posts.  I've been using it now 3-4 years after trying pastes and other liquid solder.  It works for me by far the best of what I've used over lots of years.  I've talked to the original owner on the phone.  Has some stories to tell.  A year or two ago I thought they were shutting their site down due to age.  Still up but now see it also offered at a few other places.  I bought extra when I though they might shut down.

We've got two cats, that are outside cats except for coming in 2-3 hours in the morning and evening.  Not allowed in the shop/train room, but manage to sneak in every so often when you open the door.

In reference to some other posts (yours & others) I'd say that some of us have different perspectives/capabilities on soldering, wire size and methods due to age, physical abilities, etc..  In my case at 82 and trying to 'kind-of' finish a 24 foot long double sided layout I don't have time to be wiring/soldering to the bottom of rails or joiners.  It is good info for those that it is an option for.  If I was maybe 20 years younger or building a module to take to events the story would be different but that isn't the case for me and I'll bet some others on here.  I love seeing your work and other great levels of craftsmanship on here but I'll never duplicate it if I'm going to meet some other goals.

Sumner

[JeffB]

Getting the technical info  from https://www.powerstream.com/Wire_Size.htm here are some examples.  Assuming the feeder length is 3' (6' round trip), here are the voltage drops in the feed itself:

6' of 22 AWG  wire - total resistance 0.097 ohm - voltage drop @ 0.5A = 0.048V or @2.0A = 0.19V
6' of 24 AWG  wire - total resistance 0.154 ohm - voltage drop @ 0.5A = 0.077V or @2.0A = 0.31V
6' of 26 AWG  wire - total resistance 0.245 ohm - voltage drop @ 0.5A = 0.122V or @2.0A = 0.49V

In N scale, an average sound decoder-equipped locomotive with a conventional permanent-magnet motor will draw less than 0.5A of current (even less with coreless motor). I also gave voltage drop @ 2 Amps for multi-unit lashups.  To me even 24 AWG wire would not result in excessive voltage drop. Of course with shorter feeds, the voltage drop will even be less, and more for drops more than 3' long.

I  think of myself as a king of overbuilding things, and I would still consider using 24 AWG wire for short drops in N scale as having very comfortable current carrying headroom.

Good info Peteski...  I'm guilty of overdoing it with feeder wire size, using 18ga stranded wire for track feeders to Code 70 rail on HOn3/Sn2 track and turnouts...

I have a box of small and large spools of 20ga and 22ga wire that I'll be using for track feeders on all future Sn2 module builds...  To heck with that 18ga stuff!

Jeff

[peteski]

LOL Jeff, I'm glad you found my write-up useful.  I'm a fan of over-building in general, but when we get to extreme over-building for no reason, there really isn't any need for that, especially when it's easier to deal with lighter gauge wire.

[Maletrain]

For feeders, I prefer solid wire over stranded.  It is easier to shape to the rail foot + web area so that it doesn't stick out, like stranded wire usually does.  And, with the end of the feeder tinned, and the spot on the rail at least scraped and fluxed if not also tinned, getting the feeder soldered to the rail just requires a touch with the iron with just a bit of solder on its tip.  The result is very easy to hide with a bit of paint on the rail.

Of course, that is for those of us that need feeders on rail that is already installed, so we can't attach on the bottom of the rails where it is completely out of sight.

[JeffB]

LOL Jeff, I'm glad you found my write-up useful.  I'm a fan of over-building in general, but when we get to extreme over-building for no reason, there really isn't any need for that, especially when it's easier to deal with lighter gauge wire.

The voltage drop calculator is gold...  I'm trying to convince the Sn2 modular group that 18ga is way bigger for feeder wires than we need (20 or even 22ga is overkill), but it's falling on deaf ears.

Jeff

[peteski]

The voltage drop calculator is gold...  I'm trying to convince the Sn2 modular group that 18ga is way bigger for feeder wires than we need (20 or even 22ga is overkill), but it's falling on deaf ears.

Jeff

Hey, you can lead a hose to water  . . .
If they want to seriously overbuild their wiring - so be it.

Anybody can do the calculation - it is grade-school math.

First look up the resistance of the wire (usually listed in 100 or 1000 feet units). Divide that to get per-foot resistance.  Then determine the length of the drop from the bus to the track and multiply it by two (since the electricity makes round trip over a pair of wires).

Then multiply the per-foot wire resistance by the total length from above.  That is the total resistance of that feeder.

Next take the total feeder resistance and multiply it by the maximum current (or any current you want to use) which will pass through the feeder. The result is the voltage drop over that feeder.  The lower the current is, the smaller the voltage drop.  Can't get any simpler than that. 

When doing the calculations make sure to use the same unit for all the variables. (like Amps, Volts and Ohms).

[JeffB]

Hey, you can lead a hose to water  . . .
If they want to seriously overbuild their wiring - so be it.

Anybody can do the calculation - it is grade-school math.

First look up the resistance of the wire (usually listed in 100 or 1000 feet units). Divide that to get per-foot resistance.  Then determine the length of the drop from the bus to the track and multiply it by two (since the electricity makes round trip over a pair of wires).

Then multiply the per-foot wire resistance by the total length from above.  That is the total resistance of that feeder.

Next take the total feeder resistance and multiply it by the maximum current (or any current you want to use) which will pass through the feeder. The result is the voltage drop over that feeder.  The lower the current is, the smaller the voltage drop.  Can't get any simpler than that. 

When doing the calculations make sure to use the same unit for all the variables. (like Amps, Volts and Ohms).

Yeah, the math is not a problem for me (majored in applied mathematics in college), but the online calculator is great for sending math resistant individuals to in order to make your point.  Though even with that, it's apparently a tough sell to the "let's grossly overbuild it just in case..." crowd.

So your first statement really applies here...  The only downside is that I don't want to have to wrestle with the heavier wire if I don't have to, but they're going to give me grief about not using it.

Thanks for the breakdown though.

Jeff