This is a new & improved, 10-hook mechanical punch card reader. It uses a couple 1/4" diameter springs, 693-bearings, and thin brass rods, as well as tons of M3 nuts/bolts, but is otherwise entirely 3D-printed on my Thing-o-Matic. Turning the crank 'reads' the punch card (the direction does not matter), raising hooks where holes have been punched in the instruction cards.

The instructions are pretty much the same as here: http://www.thingiverse.com/thing:33696, with a few modifications where parts changed. Assemble the main frame, and wait to add the hooks / needles until the end. The 'back needle holder' should be inserted with the 'slots' facing upward.

To insert the hooks/needles:

1. Rotate the back needle holder backwards slightly
2. Insert a hook so that it is resting on the hook_pivot_support, with the 'hook' part pointing towards the card cylinder.
3. Place a 1/4" diameter spring on the back of the 'needle', and place the hook in the needle around the hook.
4. Bend the needle down slightly so that you can insert it into the front needle holder.
5. Using the 'slot' in the back needle holder, push the back of the needle into place until it snaps into the appropriate hole.
6. Go to step 2 and repeat for all 2 hooks/needles.

The hooks are designed to capture an M2 nut, and have an M2 bolt threaded threw them. String can be looped around the bolt and then secured using the set-screw.

The "uncond_cylinder_catch" can be used to unconditionally advance to the next punch card after every read operation (such as in the operation of a simple loom), by mounting it directly on the frame. The "cond_cylinder_catch" and "cylinder catch frame" can be used to only advance to the next punch card when a condition is met (i.e. when the end of the cond_cylinder_catch lever is pulled downwards, swinging the end of the catch up underneath the cylinder end and forcing it to rotate).

It is designed to pair with three of these: http://www.thingiverse.com/thing:101068 (one hook for both sides of the counter, and one for the 'zero-detect arm').