Over the course of this week, I had a couple interesting projects, thoughts, and discoveries… Here’s this week’s items:

  • GPIO Pins Mapping table
  • 3D Printing failures with small parts.
  • Fiberglass to fix a water feature

GPIO Pins Mapping table
I’ve been struggling recently with staying organizes when a project involves a Raspberry Pi and multiple sensors or controls. When I plan it out or build the prototype I end up usually doing one sensor at a time, then when I throw it all together I find out a GPIO pin or power pin is already in use. So, when documenting and keeping track of my notes in Confluence it occurred to me that I could use a color coded table to assign the parts. It was extremely easy and useful, I filled in some extra details and used the typically GPIO Pinout images as reference, I’m surprised it took me this long to think of doing it.

3D Printing failures with small parts.

This weekend I refined some parts I was building for an enclosure for my 3d printer. The first pass had too small of holes or didn’t fit things properly, hence the need for version 2. However, in the course of printing a few components I noticed that my printer has trouble with small parts in that they don’t stick to the bed compared to larger parts. In fact, after a couple of failures for a really small part I adjusted the model to have a 1mm tall by 1 inch radius “raft” and then the part stayed fixed to the bed and printed successfully. I think the issue might be that with small parts the filament doesn’t cool before the next layer is added so it ends up a hot gooey mess. The “raft” seems like a common thing for resin printers but for my standard PLA printer it seems like overkill. Maybe just need to find the right temperature setting for the bed (hotter or cooler?) for small parts.

Fiberglass to fix a water feature

I have two small fish ponds connected by a cascading waterfall, for a long time I’ve struggled with a leak near the top where the first tank spills over into the river. When I built it, the two pieces of plastic didn’t go together and were cut rather awkwardly and fixed together with tape and sealant. Well, the sealant wasn’t great and there were gaps. I applied some waterproof foam to fix the issue and even some concrete to try and make a permanent seal. However, heating and cooling over the year caused those gaps to flex and now the roots of the plants seemed to have penetrated the area and caused a decent sized leak. So, I bit the bullet, drained a lot of the water, pulled out the old sealant, and reconnected the two pieces using fiberglass resin and cloth, I also took the opportunity to re-level the pools and give a more solid foundation with leveling sand and making less of a slope to the rest of the garden. But as for fixing the “waterfall”…first off, Fiberglass is useful but nasty, the fumes are terrible and I usually wear a respirator when working with it. Second, it seems to get everywhere. I wear simple latex gloves when using it but I always seem to get a splotch or two…or ten on my arms, wrist, elbows, and clothes. However, it works and works well. The end result this time seems to be working way better than the original sealant. It dried/cured quicker, and I did a little prep by sanding the plastic with some 80 grit sandpaper to give the resin something to hopefully grip to. I’m worried that as time goes by the fiberglass will pull away from the plastic in the same way the sealant did but hopefully the sanding helped enough. And hopefully the chemicals don’t kill the goldfish living in it.

Next step is to “hide” the black plastic edges under some flat flagstone pieces for a more natural looking river…

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