What is the best way to copy complicated shapes into CAD? Is it posable to use the CNC machine to trace round an object using the jog function? Could the data be recorded to be used for a toolpath? I have taken photographs of objects to be imported into CAD programs with limited success. What do others do please.
I take photos, import into sketchup, and manually trace it. I prefer manual, as it allows me a little more control
how you take the photo makes a difference.. camera square on to the object if the camera can zoom in, then zoom in and move further away so it can focus and fill the frame with the object. more light, more 'even' light, you don't really want harsh shadows, and you don't want the camera struggle in the dark When zoomed in you get less lens distortion, which means the straight edges of your object are still straight in the picture. I have had good success using bCNC to 'digitize' drawings which I can put flat on the CNC bed. Works fine for flat things but it is a bit of a process since the output from bCNC is Gcode and you need a tool to convert it to DXF. Forgotten the name but I can look it up if you are keen to do technical stuff.
I've done it several ways, including taking pictures. When taking pictures, follow Davids advice, but also add a ruler if possible. On my tormach I've used a probe in two ways. One was to get a point cloud, the other was to probe and jot down critical dimension that I use when drawing the object from scratch. The other ways were scanning with a 3d scanner or if the object fit, sometimes I use my scanner bed on my printer.
If you want to get the best result, and on the cheap side, google "kinect 3d scanning". There is open source software that allows you to use a Microsoft Kinect as a complete 3d scanner. I recommend using the Xbox one Kinect, not the 360, the 360 one has some issues.
Thanks everyone for the advice. What has work best for me is to place the component to copy on paper and trace round it then scan it. The other way is to is to place the component on the CNC machine and jog round it taking notes of the x and y. What would be good would be to automate the recording say by pressing a key. I don’t have the skill or knowledge on how to code this or if it’s possible.
you do not need to code it (but you do need to install some software) bCNC has buttons for recording points on the probe screen you can point at the points using a Vbit or a USB camera that is attached to the carriage like a tool. once you have recorded the points you need to convert from gcode to dxf, the program gcode-ripper does it. once you have DXF you can import into your favourite drawing/CAD/CAM system and carry on. here are my crib notes to myself Code: place drawing set 0,0,0 probe:record:drill at that point trace rest of drawing using F7(rapid) and F8(feed) to place Gcode save the file. transfer file to desktoppc (cnc machines runs off an old laptop) use gcode ripper to import it and export to DXF (~/bin/g-code-ripper...py) sketchup: import dxf complete the drawing and generate Gcode G-Code Ripper the F7 and F8 keys are ones I have mapped to the probe:moveto and probe:lineto actions in the keyboard shortcuts area of bCNC. Using the keys with the camera means I don't have to look away from the computer, jog to a point, record point, jog to next point, record, etc When I am tracing curves I do a regular step of say 10mm in X or Y, whichever suites the curve, and then fine jog to find the curve to record. you could also do 3 or 4 points on a curve (start, mid1, mid2, end) at about equal spacing and find the center from those line segments then draw the curve natively in the CAD package (if it is not an ellipse).
Thanks this sounds like just what a need. Have installed bCNC (win 10 pc). It connects to the black box ok be goes into alarm. How do I clear it please. It just say alarm if I work each of the limit switches it changes to Alarm x etc.
