OctoPrint (OctoPi) in Greater Detail

I always knew that I was going to set up OctoPrint with a Raspberry Pi at the printer. I didn't know how great it was going to be though.

I had a Model 2 sitting idle and I had already bought a WiFi adapter for it so there was zero investment to get it up and running.

The only thing I needed was power for it. I did not want to use the AC power adapter that came with it because I wanted to minimize the things plugged in. I perused the eBay possibilities and found a buck converter that took 6-24 volts in to provide power out a standard USB socket. I figured I could just tie it on the Ender 3's power supply and I'd be good to go. Well, that didn't work out. I suspect there were some sort of feedback conflicts so I resorted to my other plan of providing a separate DC power source (which I had around anyway) and that worked fine. In fact, it worked better because it allows me to keep the Pi on all the time which has turned out to be a good thing.

Once I downloaded OctoPi I installed it to the 8 GB SD card I already had in the Pi and ... it wouldn't boot. I tried that SD card in another Pi and it didn't boot there either. I tried a known good and configured SD card in the Pi 2 and that worked fine. That means a bad SD card or just a bad install. So I tried the easy thing and redid the install. It worked! I don't know what happened the first time but it's working now.

A bit of configuration and fiddling to get the WiFi to work and configure a static IP address and all was ready. This is cool! I can upload the sliced gcode files from Cura to OctoPrint and start the printer from anywhere - my phone, my tablet, or my desktop. I DO NOT want to use Cura on the Pi simply because there just isn't that much horsepower there to slice complex things in a reasonable time. Slicing and uploading from my desktop will work just fine.

I realized that I was missing something important - I can't see what is going on. I needed a camera. I looked at doing the camera that plugs directly into the Pi but I didn't like the ribbon cable idea. Routing would be a mess. I opted to look for a web cam instead. I researched a few and even looked in the local stores and decided to wait for something at a better price. I don't really need high resolution so I might even manage something used. I was going to the Toledo Hamfest shortly so I decided to wait until then to look for something. It was a good idea - I found a new Logitech C310 for $15.

I plugged it in and to my amazement it just worked - sort of. It was in 640x480 mode which is not that great for a 720p camera. A little digging and I found where the parameters for the camera were and got them updated. Now it's in full 1280x720 mode. Some fiddling with timelapse settings and I'm making little movies of the prints.

I have found that I like the 'Z-change' style for timelapse best. It's the most consistent although it does produce the shortest movie. A print with only 16 layers goes by VERY quickly.

I finally found the right camera mount - it mounts on the 'handle' making it move along with the bed. This means the print doesn't 'move' around on the bed while the video is recorded. This makes for a much more watchable video. See the photos below to see how it works.