Resistance is futile. No matter what anyone says, if you use two different wire diameters, you will have resistance going into the smaller wire. Smaller wire cannot carry the current load a larger wire can. Period. Use one diameter wire. You’ll be glad in the long run. By the way, I think your soldering job looks great.
GDS, I am pretty certain that the short feeder length, even if using 18-22 guage wire, will result in negligible voltage drop. Since he is sure to solder many feeders over short intervals, and each feeder is likely to be less than 2’ long (1’ is closer to the truth), he needn’t worry about voltage drop.
For what it is worth, I have followed numerous threads over the months dealing with soldering feeders. What it boils down to is that you can take your pick of any diameter of solid or filamental wires for feeders down to telephone wire and not notice any depreciation in the performance of your locomotives, even when running them concurrently. Some solder to joiners, some to rail segment centres, some use braid, some use solid, some solder to the underside of their rails, some to the inside web, and so on. Everyone reports that their trains run just fine.
What matters at our level is electrical continuity with sufficient voltage available to meet the amperage demands of the track. Even telephone wire does that over short distances for most applications. If you were running a huge layout with 15 sound-equipped locos, you might be better off with 18 guage feeders, true, but using the same guage as the bus is expensive and overkill.
As small a voltage as we’re using, you’re probably right. I’ll still stick with one diameter though. I’m a neat freak, and it just looks better.
It looks ok, but it could be better. You really shouldn’t see any solder at all. From the looks of your work makes me wonder how will the track sit on the road bed or anything you place it on. Plus, how will you fill in the gaps of ties? For the future, get yourself a bottle of “TIX FLUX” It’s LIQUID flux that solder’s better than paste flux. Sold at your hobbie store. Don’t never use solder that have flux in it as it doesn’t solder good at all. The solder you should use is “Light duty Rosin - core solder” It’s 0.32 Dia. and sold at Radio Shack for under $5
Solder job looks good! Keep on practicing, and you will get better! The suggestions posted are great.
FWIW…I use ( and sell ) a liquid rosin flux that’s been great. It comes in a bottle with a needle point applicator that is perfect for most any soldering to wires. It’s non-corrosive, and you can clean up any excess with isopropyl alcohol.
You HAVE to use flux, be it paste, liquid, whatever.
If you are soldering non-electrical components, an acid based flux works great. I also use, ( and sell ), and low corrosive acid flux that works great for soldering metal to metal components, such as brass strip to brass strip, etc.
One key to soldering…you need an iron with plenty of heat for the job. Most of the small irons are ok for wire to wire, but for rails, or any other job with mass to the components, you have to keep the iron on the component for way too long when using a 15-25 watt iron. This transfers too much heat to the work. A 45 -50 watt iron, like a Hakko or Ungar ( now Weller ) will transfer heat quickly, without overheating adjacent material. ( OK…shameless plug…I sell those too! )
The key is, quick on, quick off!
Rotor
Gear driven
The reason you can use smaller wire for feeders than for the bus is because you have more than one of them in parallel. If you only fed your track at one point what you said is true - you would be introducing greater resistance and hence voltage drop by using a smaller wire guage for the feeders.
It is because rail joiners have traditionally been the achilles heel of electrical connectivity in model railroading that the multiple small feeder system has arisen. Most folks who have experienced conductivity problems with rail joiners (or who don’t use them at all like me) now solder feeders at least every 3 ft, which translates into one length of flex track. In 3 ft, you are likely to have at most 2 rail joints. Some (like me) go as far as attaching feeders to every rail or track section.
The closer the feeders, the smaller the wire that can be used because the smaller the maximum load is that that wire can “see” (assumes a short distance - say 12-18 inches - from rail to bus). The worst case is a multi-unit lashup pulling an 8 car lighted passenger train with DCC (I’ll assume HO for sake of argument). The entire train is in one power section, even though train is about 10 feet long. That means that there are least 4 feeders passing the 4 amps current (averaging 1 amp each), and that assumes all feeders outside the train length are not passing any current due to opens at the rail joiners. If only one feeder is passing current for the 2 engines becasue of failed conductivity at the rail joints, I still only have a maximum of 1.5 amps. Any time I have conductivity at the rail joints, I have paralleled more feeders, reducing the resistance and voltage drop. Even just 2 feeders in parallel halves the resistance and associated voltage drop.
To get a maximum half volt drop in my feeders, I simply need less than 0.2 ohms per foot in my single 18 inch feeder. If any of my track electrical joints are good I’ll have less than 0.2 volts drop.
for feeder wires that length you dont need to worry about voltage drop at all. i had a garden layout for a while and there you really did need to worry about voltage drop. i was using chunky speaker cable and it was still a problem.
peter