As the workshop is not built yet I am doing the work in the house. As I don't want to fire it up in the house and spend the text week vacuuming the house I'm doing less messy things. One of the things i am keen to do is work with very organic shapes and being able to scan in objects. The $5 digitizing probe was a quick and dirty hack to just see what could be done with the things I had at hand. This was plan B, plan A was to buy a digitizing probe on EBay. Then I saw how much a real probe cost!After I did a back of the envelope calculation as to how long it would take to scan 10000 points I set the probe speed to 320mm/min as that would lake about an hour. The result above was pretty impressive considering what was used to make it. I did some repeatability tests, getting the probe to hit the same spot 100 times at different speeds, 320mm/s as in the scan above and then slowed right down to 30mm/min. This is the same coin but scanned at 30mm/min. It took a long time, about 10 hours. For a quick and dirty hack the results are amazing. The probe does have some limitations. It is really slow and it only comes down from above and slide off objects when the angle between the object and the needle is shallow. I wont be doing any more with the $5 probe. With bit more complexity we can make a very cheap probe that registers touch both from below and from the side. With this type of probe a much more sophisticated scanning process can be used and slipping off the object is not an issue. This is the subject of better touch probe. |