Somewhere, somehow, the little plastic battery lid had gotten misplaced on my travel mouse. Rather than to throw away a perfectly functional mouse, or to use duct tape which would make a mess and interfere with the mouse movement, I printed out a replacement battery lid.
By scanning the mouse with a 2D scanner, I was able to quickly create a replacement lid.
Scan the bottom of the mouse on the MFP scanner at a known DPI.
Import the scanned image into my CAD software as a background image.
Scale the image to the true size. (The image size and DPI gives you the actual dimension of the scanned image area. Use that to figure out the scale correction.)
Create lines and arcs to establish key features. (Use the circle-by-3-points method for the arcs.) Bonus step: measure the tilt angle and use that to deskew the image.
Create a polyline to trace the contour of the battery pocket
This technique of putting an item on the scanner can be a much faster way to design an object than to break out the calipers.
Thanks for walking through your technique, this is a really great trick! I've seen the scanner trick used in reverse-engineering PCBs before (remove all the components and then can the bare board) but hadn't considered it for modeling replacemnt parts. Neat!
Cool I use exactly the same trick. Usually scan a ruler with the object and use that to get my dimensions right.