Yes, the pencil clamp is defective. Maybe it is only defective on this one compass, however if you look at the amazon reviews for the compass (not as part of the set), there are a ton of negative reviews.
It doesn’t look that bad… Oh, look at how the graduations are already rubbing off. I guess it would be harder to stab someone with it than the old needle pointed ones.The clamp mechanism.The protrusions on the lever push against the ears on the pencil clamp, locking the pencil in place. At least it does in an alternate universe.Without the pencil in place. You can see that the clamping action is slight. The pencil is .287” in diameter (major diameter of the hexagon) and when empty the bore of the pencil clamp, with lever engaged, is .286”. This is clearly not enough adjustment.It’s flimsy too.I added successive strips of paper between the lever and the clamp.Ultimately .020” thickness of paper, on both sides of the clamp (so .040” total) resulted in a firm clamping action around the pencil.
What irritates me is that it shouldn’t be hard to make a compass that works for the same or slightly higher price. I wonder how many children are foiled in their geometric endeavours by such a shoddily made instrument.