Upgrading the Mini Kossel to Duet Electronics Part 2: Software and Commissioning

In Part 1 of this two-part series, I covered the hardware changes needed to use Duet electronics with the Mini Kossel in place of Arduino/RAMPS electronics. In this second part, I will cover installing the software and the first stages of commissioning the printer. Part 3 will cover the remainder of the commissioning process, including calibration. Continue reading

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Upgrading the Mini Kossel to Duet Electronics Part 1: Hardware

The Mini Kossel delta 3D printer is available in kit form from various suppliers, including Think3DPrint3d (T3P3) in the UK. The kits currently supplied by TPT3 include an Arduino Mega and a RAMPS board to control the printer with Marlin firmware. Although this combination can drive the Mini Kossel, a number of delta 3D printer owners have commented that this combination of electronics and firmware is barely able to handle the demands of a delta printer and attached LCD display. Users who have attempted to add a 128×64 graphics display have reported very poor performance of the display while printing.

Today, 32-bit embedded processors are cheap. So there is no longer any reason to use 8-bit controllers to drive 3D printers. A few  32-bit controllers boards are available, including the Smoothieboard and the Duet. The Smoothieboard has been described elsewhere. In these articles, I will describe how to upgrade a Mini Kossel built from a T3P3 kit to use Duet electronics and associated firmware. This article describes the hardware, and the following article will describe software configuration and commissioning. Continue reading

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Ormerod and Mini Kossel 3D printer kits compared

I’ve now built two 3D printers from kits: first an Ormerod both designed and supplied in kit form by RepRapPro, and more recently a Mini Kossel designed by Johann Rocholl and supplied in kit form by Think3dPrint3d. So here is a comparison of the kits and my experience of assembling them. I won’t try to compare print speed or quality, because I don’t have enough experience of printing with the Mini Kossel yet. The Ormerod 1 kit that I assembled has now been superseded by the Ormerod 2, so I will try to make allowances for the improvements that I am aware of in the Ormerod 2. Continue reading

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Converting the RepRapPro Ormerod to Two Colour

The RepRapPro Ormerod is sold as a single-extruder 3D printer kit. Although RepRapPro is promising to produce a multi-extruder conversion kit for it, they have not yet provided a date when this will be available. So here is my recipe for converting the Ormerod to a 2-nozzle dual extruder printer. Continue reading

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Five Tips for using dc42 Firmware on the RepRapPro Ormerod

Many of you know me better as dc42 on the RepRapPro and Arduino forums. As the owner of an Ormerod 3D printer and an embedded software engineer (amongst other things!), I forked the RepRapFirmware github repository early in 2014 in order to address some limitations in the stock firmware. My firmware fork has proved surprisingly popular with other Ormerod users. So for all of you out there, and for anyone thinking of using it, here are my top tips for getting the best out of the firmware. Continue reading

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Five things I never use in Arduino projects

I’ve been using Arduino for a few months now, and designing electronics and embedded systems for a lot longer. In reading the Arduino forum, I’ve seen a few areas that Arduino users often find difficulty with. It seems to me that some of the perceived Arduino wisdom is a little misplaced. So here are my top five things to avoid using in Arduino projects. Continue reading

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Prototyping small embedded projects with Arduino

Recently I needed to design and build a small battery-operated device with 4 outputs sequenced at a variable rate. After playing with a 555 timer IC and some CMOS flip-flops, I realised that the modern way would be to use a microcontroller. So it was time for me to learn about Arduino. Although there is a lot of information about Arduino on the web, it’s not very well organised, and the tutorials on arduino.cc don’t go as deep as I needed. I had to hunt around for the information I required. So here is a guide to developing an embedded project based around an ATmega series processor, using nothing but an Arduino Uno to both develop the system and program a virgin ATmega chip in the prototype. Continue reading

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Alternator failure warning in Piper PA28 aircraft

Some time ago I came across this Air Accident Investigation Branch report concerning a PA32R that landed gear-up following an alternator failure. The report noted:

It was apparent that the ALT caption, which illuminates whenever there is no output from the alternator, mounted between two other warning lights on the instrument panel, was very dim in comparison to these lights…

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What you probably didn’t know about the Bendix-King KI-525A HSI

The Bendix-King KI-525A HSI and associated KCS-55A compass system was a popular avionics upgrade for light aircraft until the advent of the Sandell electronic HSI and, more recently, glass-cockpit systems from Garmin, Aspen and others. Although it is a mechanical device driven by some electronics, these units can give years of trouble-free service. I know of one component they use that has been reported to fail quite often (a bipolar tantalum capacitor, C110) – when it does, the symptom is that the glideslope pointer fails to appear, or takes a long time to appear, or appears erratically. However, I want to share with you my experience of another glideslope pointer issue with one particular unit, and suggest a test to perform if you have a KI-525A in your light aircraft. Continue reading

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Moving mail, calendar and contacts from iPhone to Android

I’ve just switched mobile phones from an iPhone 3G to a Motorola Defy. Of course, I wanted to move my contacts and future calendar entries. Apple doesn’t provide any sort of general export facility for iPhone data, so this required some research. In the end, it was quite straightforward. Continue reading

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