An SD-40 and its Wheels

I have got myself a loco for the layout. It was one of the guys over at the Railwire that offered to sell me an undecorated Atlas O SD-40. I took the opportunity to get an engine at a nice price and here it is, devoid of all possible detailing:

The previous owner converted the wheels of the SD-40 to P48 standards, meaning the wheel profile is prototypical. That was good for me, since that looks better and I want it that way, but also since my (only) turnout has flange ways etc that are more P48 than standard O. The loco axle length had also been adjusted to a more narrow and prototypical track gauge. This was not equally good for me, since my track gauge is standard O.  Don't ask why. It's just is. This meant my new loco would not run on my track, unless I did something about the wheels, or rather their spacing.

So I have done some experimenting with one of the wheel sets. The conventional O scale gauge is 60 scale inches, which equals 1.25" or 31.75 mm but Proto:48 uses the prototypically accurate 56.5 scale inches which is 1,17" or 29.90 mm. That is not a very large difference, and the loco, as arrived, could actually sit tight on my track. It even powers up, and makes all sorts of sounds. But when I throttle up it immediately derails.

Since we are only talking about 2 mm, I simply separated the wheels on one of the axles by that amount. The axle is a little to short for that and I am not sure that the wheels will stay put in the long run. However, there want be much stress on the wheels on this little layout, and it might be enough to secure the wheels with a little Loctite. Another solution would be to buy new axles from NWSL. Fitting axles seems to be readily available for $1.25 each, so that is might be worth the trouble. The picture below shows separated wheels on the axle uppermost in the picture. You can see that the wheels sit tighter on the lower axle, P48 style.

Another problem is that although the gearbox of the truck is originally done for the longer axle, the original wheels were much wider. With the narrower wheels separated further apart there is a risk that the wheel with the gear slides that far out so that the gears lose contact with each other. To fix that problem I inserted a spacer between the the opposite wheel and the gearbox. The next picture shows the left wheel, with the gears, at its outermost position. It still contacts the rest of the gear assembly, even if it is a close call.

The non-geared wheel is electrically isolated from the axle, and uses a sprung pin sitting in the gear box to make electrical contact with the motor. You can see the pin in the lower right of this photo.

If the isolated wheel slides to far out from the gearbox, the pin will no longer contact the back of the wheel, and the electrical pickup is broken. To avoid that I put a spacer on the geared wheel side also. So now the isolated wheel cannot go any further out than this picture shows.

Even if I decide to buy new axles, I will probably start by just separating the wheels on the existing axles. Just to be able to see the loco run.

Painting rail

A short progress report. 

I have started to paint the rails. But running out of the old and proven Floquil Grimy Black, and since no more of that is to be had, I had to find a suitable substitute. I went for Vallejo acrylic Model Color, #168 Black grey. A little darker than the grimy black perhaps, but it will do fine.

This is just a first step. Dirt and rust will follow so the unpainted spots, which can be seen in the picture, do not matter at this point. Also, there is paint on the rail tops which I will remove later.

The Ceremonial Last Spike

The ceremonial last spike has been driven in. The event was witnessed by Sir Topham Hatt and duly photographed...

...not!

But the last spike has really been driven, although the event was not that grand, but like this:

Rail on siding spiked

All the rail on the siding has been spiked, and rail joiners have been fitted.

So now a car can roll all the way down to the poor man's bumper.

Lengthening the stock rails

When I started out to spike the rails on the other (left) side of the turnout I remembered that I had made simulated rail joints in both stock rails of the turnout, close to their ends. I had notched the rail heads and added rail joiners for added visual interest. This was when the turnout was just supposed to be a display item. You can see this in the picture below.

When laying the next pieces of rail I would either get a new joint just a few scale feet further away, or have to make that joint invisible. I did not want either of that. So I decided to make those fake cuts real cuts and lay the new rail starting from there.

So the rail joiners were pried loose and the rails cut. But once I had removed the spikes from the now loose pieces of rail, they were still stuck.

Bugger! I had forgot that it was here that I had soldered the feeder wires to the rails! And I had managed to hide theme so well that even I missed them. Well, the feeders were cut off easily enough and the rail pieces finally came off. Like here (you can see the copper colored feeders coming up between the ties).

But now I had a new problem. I had to get the stock rails electrically connected again. I did not want to attempt getting new feeders in from below at this point, so I instead decided to solder the next pieces of rails to the stock rails. Any ugly looking soldering would be hidden by the rail joiners.

Here new rails have been soldered in place.

Not that bad after all. I should have tried for a new invisible joint to begin with, rather than going this tedious route!

With rail joiners and tie plates in place we are ready and can proceed with the rail spiking proper.

Adding hardware

No work done on the layout for a long time, mainly due to a lack of parts. One parcel with tie plates, spikes and other things never turned up, and apparently got lost somewhere in transit. It took me some time to realize and accept that, order new stuff and wait for the second parcel to come through. It eventually did, and now I can continue spiking track!

But first I added some more hardware to the turnout. Not because it actually needed any, but since I could not resist the heftier look.

First I replaced the simple gauge plate I had made out of plain styrene strip with a properly bolted plate from Right-O-Way.

Then I added a second throw bar, also from RoW. The throw bar is a two piece assembly, which you CA together, with a piece of paper or tissue between the pieces to make them electrically insulated from each other. Here are the two pieces before the excess CA-soaked paper has been cut away.

And here the throw bar has been put in place.

  

Next I painted the new parts with grimy black...

 

... and applied some weathering powder.

 

Spiking rail

Finally it was time to spike some rail. But as always, just one more thing to do first - soldering feeder wires. Here I have soldered feeders to the first two rails, and then just laid them down in about the right position.

Next I wanted to mark the position of one of the rails, in reference to the ties. So I pinned down some loose rail, all at about the same position from the end of the ties all along. I tried to get a nice an smooth flow.

Once I was satisfied I marked the position of the rail, on the ties, with a pencil. Now I can lift the rails for feeder soldering as I go along, but still easily get them back in position with help of the marks.

The rail will not sit directly on the ties but on tie plates. I use Grandt Line code 125 tie plates, and Micro Engineering small (1/4") spikes.

Keeping the rail on the previously done pencil marks, the spikes are pushed or driven in with a pair of pliers.

 

 

Here are the first few plates and spikes in place - two spikes per plate - one on each side of the rail.

 

 

Once the first rail was done, I continued with the opposite rail. Its position determined with an NMRA standards gauge.