Need Help!- How to digitize a part with out making a probe

[prcdslnc13]

Back when I used to program CNC routers for my job we had a router that we could lay a cardboard template down, drive the machine manually and place the axis where we wanted and hit a button and create a point. The software that drive the machine (windows based if I remember right,this was 7ish years ago and it was old then though) would output a dxf which we could open in autocad and create curves off the point cloud.

Im looking to something similar with my router and Emc. Im currently using ubuntu vs 8.xx and I think EMC 2.3. I dont currently have anything special set up in my config file, I dont even have my limit switches wired in yet Im using the probotix stepper drivers and breakout board for my electronics.

Im not at a point where I want to create a probe sequnce or even really make a probe, I would be happy with manually jogging the machine with a fine point bit and pushing a button when I get where I want to be.

[FatFreddie]

I use Inkscape - photograph or scan the object, load it into inkscape, draw round it and then output it as a DXF. If you put a ruler in the image you can use it to make sure the scaling is correct.

[prcdslnc13]

That could work, but the problem you run into is paralax error if your not perfectly 90deg to the part and you'll also get lens distortion towards the sides of your lens's field of veiw. Even with top end lens's its hard to avoid some rounding at the edges, And Im looking do to things like door frames and window casements. So my parts will be bigger then a scanner . For this part I ended up just putting a piece of .25" round aluminum stock in my routers chuck, clamped my part and gave the machine a reference point. Then I went around the part and touched it every half in or so and wrote down the coordinates and then took that list of point's and plugged them into Autocad and snapped a spline across them and offset it .125" in to account for the radius of my "probe".

It was time consuming, but made a damn near perfect piece. What I was hoping for was a way to output those coord's I wrote by hand into a Gcode file so I could backplot them.

[chester88]

you could use the probing routines but just use a hand operated switch instead of a probe.

[prcdslnc13]

Originally Posted by chester88 you could use the probing routines but just use a hand operated switch instead of a probe.

You have a point there chester. I thought about doing that but I had trouble getting my routines to come out the way I wanted them too. You wouldnt have a sample probe routine would you?

[chester88]

Sorry no I don't

[voltsandbolts]

I know you were trying to not make a probe, but how about mounting a roller tipped micro switch to your router and set it just above table height. Then move the X and Y accordingly to collect data points as the switch activates passing over the pattern. It won’t be super accurate but should give you something to work with.

RobWms.

[prcdslnc13]

I actually needed that for a quick project I was going to do. I am eventually going to make a probe. Maybe this weekend even if life allows me some time haha. EMC is so flexible I was just curious if anyone had made a utility to do this yes.

Maybe that will be my first custom python project....