I fabricated a 5'x4' CNC Plasma Cutter and downdraft table. I am using the cutter to make planar sheet metal forms that I fold into 3D objects and sculptures. Since I don't have easy access to a full machine shop, I tried to use off the shelf components as much as possible for the keep components.
Linear motion parts (bearing blocks and gantry supports) came from CNC Router Parts. Z-axis assembly utilizes 80/20 compatible aluminum plates and a few custom welded steel brackets. Since lateral forces are minimal for plasma cutting, the X-Y motion is belt driven (GT2 9mm width belt).
The downdraft table is my own design built from steel channel, 2''x3'' tube, removable 1/16'' steel plate to contain dust and sparks, and a removable steel slat cutting surface.
Ventilation provided by a 16'' 4/5 HP utililty blower.
To accompany my CNC machine, I'm attempting to build my own high-power induction heater. This will be great for small forging projects, or even just putting quick bends into bars and rods. The pile of parts is, from left to right: two IGBT bricks w/ capacitors, two high quality ceramic capacitors, a transformer, and my home-made gate driver.
The gate driver (right) has two main parts: a transformer and a full bridge inverter. The transformer takes a weak input signal (say from a signal generator or PWM circuit) and creates four nearly identical but electrically isolated signals. Each of those signals drives power transistor in the proper sequence converting 15V DC into a 70-80 kHz square wave powerful enough to switch the the IGBTs. You can look at the whole induction heater as a two stage inverter. The gate driver inverts the 15V power which in turn drive the IGBTs to switch rectified mains power. This project, based off of this design has really pushed my practical knowledge of electronics - there is a real art to transformer winding guys!
I really enjoy playing around with basic geometric forms. This is an in-progress shot of a BBQ and firepit made out of sheet metal. When not in use, it casts an ominous shadow on my yard, which I enjoy. The weak link in this project was cutting out the forms and holding them in place. I was using an angle grinder with a cutting disk and even my best efforts left enough gaps to make TIG welding impractical. Despite the difficulty, I got the sculpture bug from this project. Realizing how important it is to start out with good cuts is what motivated me to make the CNC Plasma Cutter.