Tuesday, September 16, 2014

A Terrible Compass

DSC05174It’s back to school time and Henry needed a protractor and compass for 6th grade. Felice went to K-Mart and bought a Westcott Two Piece Math Tool Set. It was extremely inexpensive. For some reason the K-Mart page has a weird typo, calling it a “Westcott Clauss Math Set Protractor and Compass”.Even weirder, the combo is not listed on the Westcott website, as far as I can see. Unfortunately the compass is an utter piece of garbage. The video below shows the problem…  

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.

DSC05189It doesn’t look that bad…DSC05188 Oh, look at how the graduations are already rubbing off.DSC05187 I guess it would be harder to stab someone with it than the old needle pointed ones.DSC05176The clamp mechanism.DSC05178The 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.DSC05182Without 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.DSC05177It’s flimsy too.DSC05184I added successive strips of paper between the lever and the clamp.DSC05186Ultimately .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.

Thursday, September 11, 2014

Channel Master 6520 AM Radio

DSCF3052Picked this up at a yard sale last weekend, for $5.00 (half off…)DSCF3055DSCF3057 DSCF3058 DSCF3059 DSCF3060 DSCF3061 This is the only really exciting thing, the battery compartment.DSCF3065 Batteries are held in a tube for easy handling.DSCF3085 Compartment has captured screws that use a coin for a screwdriver.DSCF3070 DSCF3074 DSCF3077 DSCF3079 DSCF3080 Grommets are a bit worn…DSCF3081 Causing the tuning capacitor to cant to the side.DSCF3082 Neat heat sinks on the red headed transistors.