2 major problems

2 major problems

A month has passed since I started to set up my old n-scale model railroad again. It’s not been as straight-forwards as I thought it would be. Getting the tables up wasn’t a big deal. I found one bridge that was kind of broken and is missing a small part, but that’s something I can repair and rebuild. One track was slightly bent as it was sticking out and must have bumped into something. And that was also very simple to fix. Then I started to connect everything. All cables were saved so it was just a matter of finding out where they should be and reconnecting them, and that also went fine. But as soon as I connected the power, I noticed that the servos under a lot of the turnouts were behaving strangely. They did not stay fixed in one spot but moved irrationally. This was the first major problem.

As far as I understand it, the servos I bought back in the day were pretty cheap to be honest. They did their part then, but now a number of years later, they failed for me. So after trying to find out what’s causing this, I started to replace them. I bought a large number of them the last time, and I still had around 30 unused servos in that good-to-have shelf somewhere. But even after replacing the servos, the new ones also caused the same problems for me. After testing them with my home-build servo calibration tool, around 5-10 out of the 30 were fully functional. The others failed with the same problem. So I used the good ones and bought new servos at the same time. A couple of days later, all turnouts were working fine again. Phuuu. Lesson learned, don’t buy cheap stuff again and try to aim for quality instead.

Then comes the second major problem. If you have checked out my webpage, you know that I control my entire railroad with Traincontroller Gold and the DCC system I use is from Lenz. The Lenz controller itself does not have a PC connection, so I have a Lenz USB/Network connector that talks to the DCC controller over Xpressnet. But I lost communication with it on both USB and network over-and-over with a 5-30 min interval. Both protocols stopped working at the same time. The rest of the XpressNet devices worked fine. So after a lot of testing, including a test with replacing the Lenz with a DR5000 central, I ended up with buying the new Lenz LZV200 controller. I was quite happy when I got it home and connected it to the railroad. That went fine and I could connect to it from Traincontroller and also work the turnout from the Lenz LH101-R hand-controllers. But Traincontroller could not switch any of the turnouts. 

The turnout controller I use is a 64-servo controller I designed myself and that connects to the railroad over the XpressNet and not the track connections as they usually do. Much easier design and worked fine up until now. But the LZV200 does not send the turnout signals out over XpressNet, only to the track when it comes from the TrainController. So there I was, with the old DCC controllering that I lost connection to all the time, and the new one that worked fine, but without any turnouts working. 

My solution to this was to redesign the 64-Servo controller to skip the XpressNet connection and instead get the signal from the tracks. This went fine and I managed to get that to work. At the same time, I redesign the circuit boards and order new ones from one of the vendors out there that make a living of creating circuit boards. I also reprogrammed the application that exists on Linux from C++ to Python as I code Python on a daily basis, but havent touched C++ in 7 years. That also went fine, so I now have a fully upgraded 64-servo controller working. I have 3 of them spread out on my railroad and all work great with the track connection instead of the XpressNet connection. 

I will update the page with the 64-Servo controller with the new schematic, Gerber files and Linux application in the upcoming days. But all in all, I’m quite happy with the progress I made over the last month. Even though I didn’t build any landscapes, houses or new tracks, a lot of electronics have been solved and I ended up with a more stable solution. And at the same time, one of my other hobbies is electronics and I also enjoy Python programming. So it was a fun and enjoyable experience for me. And not to forget, I now have a working model railroad again!

One thought on “2 major problems

  • Anonymous

    That’s really amazing work. As usual you are simply great in whatever you’re doing. Happy for you. Keep it up 🙂

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