Add wipers to the locomotive frame
Adding wipers to the locomotive is easier than adding them to the tender trucks. I will chicken out and start with the simpler job.
I start with either N scale or HO scale crossover ties from Fast Tracks, https://www.handlaidtrack.com/ Any PC board ties could be used, the crossover ties are simply longer and I can cut one long board instead of linking together shorter ties. The HO scale ties are 1/16” thick, the N scale ties are 1/32” thick. Rarely, on tender trucks, I need the little extra clearance of the N scale ties. I prefer the HO ties; when heated, there is less chance of the copper pulling away from the fiberglass core. It happens.
In 2018, the HO ties were a little over 6.25 per fret, the N scale was a little more than $9 per fret. Shipping was about $6 to me, so I ordered 2 frets of HO and 2 of N scale. That is a lot of tie length, but I figured I had about 20 engines to convert and I was going to make many mistakes while learning.
I use 0.0125” diameter phosphor bronze spring wire from Tichy Train Group https://www.tichytraingroup.com/ . I think 0.010” would also work. I found .015” was too stiff, it created too much resistance to rolling. The thinner .008” wire was too fragile for me, it easily caught and bent when handling the loco.
One crossover tie and one 12” length of wire is more than enough to do one locomotive, up to 4 drivers in a row. Longer and you may need to splice PC ties. The image below has both a full-length N scale tie and HO scale tie.
I use coarse diagonal cutters to cut the PC board ties. The fiberglass is very abrasive and would soon ruin fine flush cutting pliers. You can use a Dremel cutoff disk, but I don’t care about the appearance of the ends.
Here I determine how long the tie should be. I like to run the PC board from front to rear axle, this wheelbase is about 3”. It does not have to be terribly exact, a bit longer allows for a little misplacement.
I scour the base plate with 220 grit sandpaper. The baseplate is coated liberally with flux, then tinned. The PC board tie is fluxed and tinned on both sides.
If you care, here is my soldering station. It is an Ayoue station, lead free tinning flux, 1mm lead free rosin core solder, and a copper clad kitchen scrubby pad to clean the iron. I purchased a variety of tips for the iron, tried them all on various things, and now I normally use only two heads – the broad tip for lots of heat, like soldering a PC tie to a large chunk of brass, and a fine oval tip for almost everything else.
The PC tie is clamped with a self-closing tweezer. I use the broad tip to deliver more heat to the large chunk of brass and flow solder under the tie.
It is easy to accidentally run solder down the tie and short to the frame. I always verify there is no continuity between the top of the tie and the frame. Later, I verify the wipers are not shorted to the frame.
I clip wires about the same diameter as the drivers and sweat them to the top of the board at an angle. That provides springiness to hold them on the drivers. If you don’t like the angle, bend them.
The wipers are obviously much too long. Better too much than too little. I clip them just beyond the driver flange. They are unnoticeable. Riding on the edge of the flange is simple, self-cleaning, and keeps them high so they don't hang on the ties.
The locomotive is done. On to the tender.