Home Made CMM

[SPerman]

I am reverse engineering some parts with complex shapes and odd angles. I thought I was doing pretty good, but once they all started stacking up together it was a mess.

I decided to take a retired 3d printer, remove the head and replace it with a magnifying camera.

I printed a reticle to place on the monitor. I drive the printer and get the coordinates through pronterface.

I've only measured a couple of parts so far, but the results are better than expected. It is a bit cumbersome, but way more accurate than I can get with hand tools.

[DennisD]

Nice! I look forward to watching this develop. Perhaps you will share your code and insights? (Pretty please.)

[Frederick_Law]

I just take a photo of the part, with ruler. Insert into sketch and sketch on top.
Also used mill with digital readout. Get coordinate with edge finder. Plot it in AutoCAD.

[SPerman]

Nice! I look forward to watching this develop. Perhaps you will share your code and insights? (Pretty please.)

I think you are over estimating the elegance of this project.

I am simply using the gantry of the 3d printer to (somewhat) accurately position the camera, and report the coordinates.

I already have all of the parts in cad, but they needed to be more accurate than what I had been able to accomplish.

Step 1: Layout the points to be measured

The frame is the part with the most features, and is where all of the other parts come together. I had over 100 points before it was all said and done.

I'm using software for boards with Marlin firmware to both position the gantry, and report the X Y position.

I jog the gantry until the crosshair is aligned with the feature I want to measure, send the command to the printer to get the coordinates, and enter those numbers in a spreadsheet.

I printed the reticle on clear transparency film and taped it to the monitor. Not a very sophisticated solution, but it works. The output of the USB camera is being displayed through the default microsoft app.

The only code involved is this macro from Artem. I use that to import the point cloud into a sketch in Solidworks.

Once I had the points imported, I added enough geometry to make sense of it all.

The next step is to overlay this with the model and started correcting things that are off.