|Construction:||20 and 30 mm plywood, glued, screwed and bolted|
|Linear guides:||X axis runs between 4 drawer guides|
|Y axis runs on 4 drawer guides|
|Z axis runs between 2 drawer guides|
|Lead screws:||M12 ISO threaded rod with nuts cut from Polyamid|
|Motors:||400 step, NEMA 23, 1.7A stepping motors|
|Motor drivers:||Driver kits from Pollin Electronic, 2 amps.|
|Spindle:||Proxxon IB/E, max. speed: 20,000 RPM|
|Tools:||Proxxon 1 mm and 2 mm mills with 3 mm shafts|
|CAD:||QCad V.188.8.131.52 (RibbonSoft)|
|DXF to G-Code:||Ace V4.0 beta (DAK Engineering)|
|G-Code to plot:||Code editor and backplotter V.1.2 (NC Plot)|
|CNC:||TurboCNC for DOS V.4.01 (DAK Engineering)|
Touch probe details
Based on a Renishaw probe. Briefly: each of the 3 brass prongs of the probe (two are visible) is pressed against a gap in a brass wire, by a spring - just visible in the centre. This completes a series circuit:
-__o____o____o__+Operation: The probe is moved toward the object. When the probe touches, one of the contacts is opened, the circuit is broken and the current position of the probe is recorded. The probe is then backed away from the object and the circuit closes again.
NB. The preferred material for the electrical contacts is hardened steel - not brass.
a 2D scan with the touch probe
I used TurboCNC to scan a crudely-made, but finely-adjusted prototype part. It found the centres of the two holes and the positions of the two arms (marked red) and these dimensions formed the basis for a CAD drawing. The milling machine then cut out the finished part.
a 3D scan with the touch probe
The Vitruvian Man on an Italian €1 coin rendered in 9 colours, like a relief map, using a short BASIC program. The measurements were made on a 0.1 mm grid.
another way of looking at it
Here, the same 150 x 150 "point cloud" was rendered in a different way: comparing each height measurement with its north-westerly neighbour, noting the difference in their height and then shading its pixel, lighter or darker accordingly.
A noisy image, but perhaps the best that can be expected from a touch probe with brass contacts. Some tweaking needed there.
Brush plotNew Year's Greetings in Japanese. On the left is my original CAD drawing. I then spent some of the time between Christmas and New Year adjusting the program until it was able to produce something resembling my model (the small picture above.)
Drilling printed circuit boards (PCB's)
After I had etched some printed circuit boards, the machine drilled the holes.