Power Loss Recovery Could Create 3D Printed Drops

[Geek Detour] had a mystery to solve. A round part he printed had a distinct pattern of drops. If you've been 3D printing for a while, you know that pauses in printing can cause spots like this. He also showed a perfectly printed version of the same part and claimed that it came from the same printer with the same material and even the same slicer settings. So what was causing the blobs? You will find the answer in the video below.

As you can guess from the title, the problem was the power failure recovery feature built into the printer. Although there's a lot going on in the video, you can break it down into a few things, all of which you can fix in one way or another, including the simple fix: disable power outage recovery.

If you have never used a printer with power outage recovery, the intent is to ensure that you can pick up a print job where it left off in the event of a power outage . To do this, the printer periodically writes status information to the SD card. If your SD card is slow or you are trying to print from the same SD card, you can trigger this problem. But there is more than that.

The first problem is that smooth, round objects like this tend to generate a lot of gcode. You can control this in several ways, including at design time and by setting the slicing resolution. Additionally, you can make sure your firmware supports arcs and have your slicer emit arcs or use a plug-in for Octoprint called arc welder. This can greatly reduce the amount of gcode involved in these arcs.

Another possibility is to increase the buffers in your firmware. If you can rebuild Marlin, it's not very hard to do. The problem is that using the power loss feature also blocks the SD card, so the more you can read ahead, the more time it has to write to the card in the event of a power loss. By the way, there's an Octoprint plug-in called Buffer Buddy, which can give you some insight into your printing problems, although it can also freeze your printer, especially - we've found - if you Have enabled Meatpack to compress gcode to serial, too. Even if you don't want to install it, the discussion of why curved lines sometimes cause blobs even on USB is well explained in the README, not to mention the related blog post.

We were also impressed with [Geek Detour]'s time lapse videos which are quite cinematic and use a motion control camera. If you want to know more about arc welding (the 3D printer type, not the spark and metal type), we've already covered that. If you want to learn more about making time-lapses of your 3D prints, we've covered that too.