Lennart's Model Railroad Blog

Lennart's Model Railroad Blog

About this blog

This blog is about my current model railroad layout project; The N scale "Summit" layout, which is a freelanced interpretation of the Southern Pacific Tehachapi tunnels and their surroundings. Or at least, that is what it is meant to be. What it will turn out to be is another matter. The banner photo above shows what I want to recreate in N scale.

Bad decoder

Rolling stockPosted by lennart Thu, January 29, 2009 21:37:56

As I said in the previous post one of the engines I installed a TCS M4 decoder in turned out noisy. Some kind of mechanical noise. So I sat out to fix that.

The first thing I saw when I disassembled the loco was a tiny piece of wire insulation on top of the gears in one of the trucks. Aha! Simple as that. So I removed that (strange I did not see it when the loco was assembled since it was shiny red). Back to the track, but the noise was still there.

To make a long story short, the noise turned out to come from vibrations in the draft gear, spreading to the frame. Don't ask me what caused that. I don't have a clue. In the end I managed to dampen that vibration by applying some grease around the gear fittings. The engine was assembled again and ran much more silent. There was still some noise when going in reverse, but I decided I could live with that.

I then played around with the two newly decoder equipped locos, MU:ing them, programmng light effects etc. Then all of a sudden, the formerly noisy engine started to jump ahead by its own (throttle down to zero) with flickering lights! The decoder seemed to give off short and regular bursts of power to the motor. If the engine was removed from the track and then put back again it first sat silent but after a while started to "jump" again. I tried a factory reset and other tricks but nothing helped. In the end I took the decoder out (it still behaved in that way when not attached to anything but the motor and track power) and sent it off to TCS as a warranty issue. They promise a "no questions asked" guarantee scheme so I hope to get a new one back at their expense. Sigh!

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Two decoders installed

Rolling stockPosted by lennart Sun, January 25, 2009 19:02:27

Nothing to show has really happened on the layout during the last few days. I have glued the turnout I have been working on lately in place and started laying some track leading up to it. That track is far way in a corner and is hard to reach. So getting the tie plates in is a little (understatement) tedious.

So I turned to decoder installation instead.

I have done the two GP38s from Life-Like. These engines are not quite DCC ready. Well, they have a split frame mechanism, but the motor does direct contact with the frame halves. So that had to be changed.

On top they have a PC (Printed Circuit) board with a LED in each end. I intended to reuse the LEDs, and the PC board itself as a holder for the LEDs.

I simply removed all resistors and capacitors from the PC board, and also made a few cuts in the foil. This effectively isolated the LEDs and also supplied me with some empty soldering pads where I could attach the decoder's power pickup wires.

After some practical tests I also decided to replace the LEDs, since the light from the factory installed ones was barely visible. I replaced them with brighter LEDs I happened to have lying around. They are perhaps a little too white and bright, but I like that better than lights that do not show unless you turn off the layout overhead light.

Once the PC board was stripped and the LEDs replaced the rest was fairly straightforward:

- I soldered the motor wires (gray and orange) to the motor contacts, and put some tape over the contacts so that the motor would no longer make contact with the frame.
- Soldered the power pickup wires (red and black) to points on the PC board that still made contact with the frame.
- Soldered a 1000 Ohm resistor to each LED, and the decoder's common function wire (blue) to each other LED leg.
- Soldered the white wire to the forward LED resistor and the yellow wire to the rear LED resistor.

After having some difficulty figuring out the TCS way of dealing with light function CV programming I finally managed to make my F1 button to turn the headlight on and off, and the F2 button to control the rear light.

Both engines run well but one of them makes some kind of mechanical noise. I have not had time to troubleshoot that. This was the first decoder I did of these two and I did not cut the wires very short. So I ended up with quite a bunch of wiring on top of the decoder. I tried to keep them out of harms way with the help of some tape, but maybe it just became a too tight fit for the body shell, since the frame does not seat properly at the rear end. I will redo the wiring on that one and hopefully the problem goes away. Any ideas anyone?

The second two function wires are unused for now. I have this wild idea that I’ll some day try to have oscillating top lights and a steady head light down on the cab. That would require two decoder functions in each direction. I do not how to accomplish this. It would probably require miniature LEDs and optical fiber. Or I might install a beacon on the cab roof. Anyway, that is why I wanted some extra function outputs.

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Wheels not in gauge

Rolling stockPosted by lennart Wed, January 21, 2009 20:45:27

I have not yet installed my so far only turnout, but I have weathered its rails and tie plates. I have also added wiring so that it can be hooked up to the track bus.

The latter also made it possible to test run some engines through it. Or back and forth on it, rather, since no extra track was attached. My two SP U25B:s from Atlas had no problems, except for a bit of wire soldering that protruded a little too high. Once filed down that was no problem either, although the wheel flanges are not very low profile but more towards the pizza-cutter variety.

My Life-Like GP38-2:s scored less good. For starters they climbed the wing rails when passing the frog. The NMRA gauge soon showed that the wheels were not in gauge. They sat to close to each other, and that was true for all 4 axles on both engines! I took the trucks apart and managed to adjust the gauge. After that they managed the wing rails. But on the other hand they caught on a point when taking the diverging route. The wheels were now a little too far apart, so I made one more tiny adjustment, and the problems seemed to disappear.

Lesson learned: The wheel flange height does not seem to be a major problem on handlaid code 40 track and turnouts. The wheel gauge on the other hand is very critical. But that is at least possible to adjust. It would have been tougher to modify the flanges.

Just for the sake of it I brought out another engine, from my old CNW layout. An Atlas GP30. It negotiated the turnout without any problems. Good job Atlas. Shame on Life-Like ;-)

I have also come around to ordering decoders for my SP engines. I went for TCS M4 decoders. I have only used Digitrax decoders so far and thought it was time for a change. Also, I wanted more than 2 function outputs, so the M4:s seemed to be a reasonable option. I ordered them from a British shop, DCC Supplies. I ordered them last Thursday night and today they arrived here in Sweden. Incredibly fast, considering two of the days spent was Saturday and Sunday. When you order something from the US you can have to wait for weeks for the stuff, but then customs is involved and they seem to take their good time (Can we persuade Obama to have the US join the European Union?). Anyway, now I can't decide what to do next, lay track and install the turnout or install decoders...

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Last two cars in batch

Rolling stockPosted by lennart Fri, September 05, 2008 19:40:58

This is an edited version of the post from the 5:th of September. I have since given the cars a flat finish, and the new photos below show the cars in this less shiny state. The original post read:

"I have done the last two boxcars in the ongoing batch. Nearly, done at least. They still need a flat finish to tone down the shiny look. But since I have used artist oil paints for this job it will take for days before the paint has dried enough for that. Here is what they look like without that final finish."

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More boxcars

Rolling stockPosted by lennart Tue, August 26, 2008 20:41:41

Work has taken way too much time lately, and time spent on the layout has been practically none. I have only managed to lay a short stretch of track and weather two more boxcars.

I've done one SP car and one Sante Fe car. As on the previous cars I removed the roof walk, moved (lowered) the brake wheel and replaced the grab irons. On the SP car I also cut the corner ladders, as there would be no reason to get onto the roof with the brake wheel on a much lower level.

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