Adding filament monitors to the Hemera tools

The imminent 3.2beta release of RepRapFirmware includes support for filament monitors connected to Duet 3 expansion and tool boards. This post describes how I added filament monitors to the two Hemera tools on my E3D Tool Changer.

Improvements to the Hemera Tools

Since building my first Hemera tool controlled by a Duet3D Tool Board, I have built a second one and made some improvements.

Large Kossel update

My large Kossel variant has been running for several years now. It is reliable and produces good prints. I have however replaced the extruder drive and the power supply by different models, and added a filament monitor. I will now describe these changes and the reasons for them.

Converting the E3D Tool Changer to Duet 3 with Hemera Tools (Part 2)

Configuring the Duet 3

The Duet 3 configuration and other system files I use are based on the ones that I published for Duet WiFi/Ethernet running RepRapFirmware 3. They are configured so that X0 Y0 is the centre of the bed. The changes I made for Duet 3 are:

Converting the E3D Tool Changer to Duet 3 with Hemera Tools (Part 1)

The E3D Tool Changer is a versatile platform for multi-material 3d printing, laser cutting/engraving, and associated techniques requiring a stable XYZ motion system. Although it is also available with fewer tools or no tools, the common configuration is four 3D printing heads using Titan extruders and 780mm Bowden tubes. It is generally recognised that direct-drive print heads can deliver better print quality than heads using long Bowden tubes, and the Titans are not as good as some competing extruders. So the arrival of the E3D Hemera direct drive extruder provides an interesting upgrade path for the Tool Changer.

Using exceptions in C++ embedded software

For several years I have been the lead developer of RepRapFirmware, which is firmware for 3D printers running ARM Cortex processors. Until recently I saw no compelling reason to use exceptions, so I compiled the firmware with gcc options -fno-exceptions -fno-rtti in order to keep the code small.

Dangerous failures

Sometimes, equipment that is supposed to be designed with safety in mind turns out to be unsafe. Here’s an example I came across a few years ago: a mains-powered smoke alarm installed in a top-floor flat:

Switching from Sage 50 to Xero Accounting Software

For once, here is a non-technical post from me. I’ll describe my experiences of changing from Sage 50 to Xero accounting software. In particular I’ll highlight a number of pitfalls that you might wish to be aware of prior to switching to Xero.

Improving the Robotdigg SCARA printer

In the first post in this series I described how I strengthened the bad T-frame of the printer and added adjustable levelling feet. These improvements made it possible to produce prints. The conversion to Duet electronics described in my second post improved print quality and provided faster print speed. However, the large amount of backlash in the distal arm joint drive remained, along with the lesser but still serious backlash in the proximal joint drive. If I was ever to get good prints from this printer, the backlash in both joints would need to be addressed.

Converting the Robotdigg SCARA printer to Duet electronics

In my previous post I described the Robotdigg SCARA Arm 3D printer in its original form. This post covers the conversion to Duet Ethernet electronics. It may seem odd to use top-of-the range electronics with budget mechanics, and I am not suggesting that it would make sense for other owners of this printer. In my case it made sense because I needed a test bed for testing and maintaining SCARA support in RepRapFirmware, the firmware that runs on the Duets.