I recently bought a SIP Migmate 150 DP gas/gasless welder, and as my first project using it I started building a cart for my welder. But when I started welding I was puzzled by the bad results I got. I have not been welding for may years, but then using a PRO ESAB welder. But now all my welds where really bad, and with a lot of splatter. I noticed that the wire feed was very uneven, and googling around I found a lot of information about this brand of welders and their inherent wire feed problems. In addition to the wire feed problems I had several occasions of porous welds, indicating that there was problems with the gas-feed.

For my CNC project i originally intended using my converted PC power supply for powering the stepper motor drivers. However when testing the CNC mill I soon found that applying higher voltage significantly raised maximal speed and torque in my system. Therefore I needed to make a power supply with higher voltage output. As my stepper drivers have a maximal voltage rating of 35V I aimed at 32V output. And as the current rating pr driver is 2,5A I wanted to be able to supply at least 7,5A.

After short time my Roomba would no longer dock correctly. It tried docking but did not seem to detect the docking station/home base. However when plugging the charger directly into the Roomba it charged correctly. Here I will show the process of finding the fault and fixing it.

For my next CNC build I am going to make a PCB router, based upon a Proxxon KT70 compound table, and a dremel rotary tool.

I need to ensure that the steppers I select do have enough torque to turn the leadscrew, and therefore needed to find the minimum torque needed to turn the hand wheels. But the torque wrenches I could find in nearby tool stores where not suitable to measure such low torque values, so I needed to find the torque in a more practical way. Here is the description for my "Torque Approximator" setup.

With the introduction of the A3977, and now recently the upgraded version, A3979, Allegro microsystems have made stepper motor driver design a simple task.

Here I will show you some techniques for soldering very small, fine pitch SMT packages using standard soldering equipment.

These techniques will help you to master the SMT soldering skills needed for assembling for instance my stepper motor driver board.

The methods described here are based upon my personal experience working with electronics for several years, but there might of course be other methods as efficient (or even more efficient).

Finally I have had some time to finish the CNC conversion (actually CNC mill conversion) of my Sherline lathe. It is based upon a Sherline 4000 lathe, a Sherline CNC conversion kit and an old milling column from a SpectraLIGHT mill.

Sherline have good descriptions delivered with their kits, but usually a bit sparse on the illustrations. This description is much like the Sherline description, but I have added several pictures to aid you if you are thinking of doing the same conversion of your Sherline lathe. Also during my work I fell into a (in retrospect, obvious) pitfall, and hopefully by describing it here you will not do the same error.

The newer models of Roomba vacuum cleaners from iRobot feature a serial interface, enabling remote control and debugging of your Roomba. Here I will describe how you very easily can make a cable connecting the Roomba serial interface to a PC trough USB or RS232, or directly to an AVR microcontroller.

When I started using the AVR micro controllers back in 1999, I coded most of my applications in assembly. After a while GCC for AVR became available, and now, with the integration of GCC support in Atmels AVR studio, starting with GCC for the AVRs is now as easy as coding in assembly.

For my sherline CNC project I needed a high current power supply capable of powering the logic on the stepper motor drive boards, and deliver high currents to the stepper motors. Suitable power supplies was priced at several hundred dollars. But I had an old ATX computer power supply in my basement and decided to convert this to a suitable power supply for my CNC project.