I want to be able to monitor my CNC mill with a cheap USB HD camera mounted on the spindle. I chose the Creative Live! Cam Chat HD (VF0700) - 1280x720p as it is very affordable and does not require drivers on any OS.
For this I could use a USB microscope, but the price is higher and they are usually too big. A normal camera can not focus closer than about 10 cm.
So I need a lense of some sort, preferably a cheap one. The cheapest one I found in my house was a loupe I use to look at SMD soldering. It is made to examine stamps, jewelry and other small things and costs just 20kr (ca. $2). Just mount it in front of the camera and suddenly the focus is down to 3-5 cm. Instant macro! :)
Step 1: Buy a Cheap Microscope or Loupe
It is just a plastic stand-alone case and a glass lens, and can be bought here:
Step 2: Tape the Camera to the Lens of the Loupe
I took apart my webcamera to make the new casing for it.
Place camera lens so it is about centered over the loupe lens. The position does not need to be precise.
Step 3: Fold Loupe Around So It Fits Your Camera
Then the loupe can be folded all around it for added protection.
With another type of camera there may not be space to fold the case around. Unnecessary plastic bits can always be cut away.
Step 4: Mount It Where You Want It
I used TACK-IT to temporarily mount it to my mill, but I´ll eventually drill holes and screw it in place, together with a LED light.