In the thread: http://familywoodworking.org/forums/...ead.php?t=7083 I reported that the jig that I purchased to hold small parts:
had proven to be a disappointment. The two clamping surfaces a strictly parallel, and they are not good at hold really odd shaped pieces such as those shown in the photo below:
I found one of two things. The ratcheting mechanism would slip when attempting to tighten the jaws around the part or the jaws would tighten on the part but they would be gripping such a small portion of the edges that the router would tear it loose in action.
The combined use of pliers and a hold down stick as shown above did the trick. In talking to others about this pliers technique and in thinking about it some more I realized that I should not have used it. If the pliers had ever touched to bit, things could have flown.
Arthur on the Canadian Woodworking forum suggested “How about a woodscrew clamp--no need for parallel surfaces to clamp on”:
Both Ken in Regina and I suggested augmenting the clamping of the woodscrews surface with sandpaper. I glued strips of 100 grit Norton sandpaper to the clamping surfaces of a 10 inch Jorgensen woodscrew with 3M Super 77 spray adhesive.
I tested this with about 20 pieces of various shapes and sizes and with 4 different router bits. The routing job was good and nothing slipped .