It's possible to build your own seismometer with mostly plumbing parts, but I found that it was likely cheaper to buy the SEP seismometer kit and have it shipped from the UK. I don't find this kit for sale anymore, but I didn't search exhaustively.
I wrote my own software to do the logging (Windows software was available, but I didn't want to waste a PC for this purpose and used an old NAS server instead, and its 266MHz ARM CPU and 32MB RAM were more than enough for the task). Last restart of that software was in 2014 according to "ps".
Since I set everything up more than 9 years ago, there has been nearly no maintenance work. I don't think I've touched anything for more than 5 years. That last restart was likely due to a power failure.
The distance to the epicenter was 2825 km to be exact (25°).
Earlier this week there was a M7.7 quake near the Commander Islands which also saturated the seismometer. The distance was 7143 km (64°). At that distance the surface waves dominate.