I had read in a Make Magazine post on an efficient and reliable way to zero your CNC. They used a USB microscope camera. I thought it was a great idea and here is how I implemented it.
Here is the camera:
Here is the bracket I designed to fit it as close to the spindle as possible.
And here is the finished product:
The camera has LED lights on the tip and they work great.
I milled with two materials. Teak on the top one and a plastic called Starboard on the bottom. I wanted to use a hard wood because I loved the look but don’t think it is the right material for this design because it will crack after too much pressure. The plastic is hard enough but will take the pressure of the bolt to tighten everything into place. I think two are needed as to keep the cameras vertical alignment as solid as possible. Ideally I would have milled this out of aluminum but don’t think I know how to handle that yet. If someone is interested in doing this also but want to do it in aluminum, please let me know. I’d gladly share the files and would be interested in the aluminum version. I also have no drill press so I couldn’t countersink the screw and tap a thread. Right now the design has a 1/4-20 thread and cap screw as the final idea.
As a proof of concept I think it works great. I need to see if the current setup will drift over time with the vibrations of normal operation. It would be ideal for the camera to be attached to the spindle head somehow into one of it square sides as opposed to the cylinder to solve the possibility of drifting.
To view the image of the camera I’m using a demo version of a software called Scopebox:
It allows me to display a center mark overlay. I think it’s only for the Mac. The camera comes with software for the PC that I think already does the job but I can’t test it as I don’t have a PC. The hole you see on the center of the screen is from the smallest tool I have, a .032 square mill #122. I marked the material and then moved the camera over to find it. This gives me the offset numbers.
Let me know what you think.