Thursday, October 23, 2014
Tuesday, September 16, 2014
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.
Thursday, September 11, 2014
Picked this up at a yard sale last weekend, for $5.00 (half off…) This is the only really exciting thing, the battery compartment. Batteries are held in a tube for easy handling. Compartment has captured screws that use a coin for a screwdriver. Grommets are a bit worn… Causing the tuning capacitor to cant to the side. Neat heat sinks on the red headed transistors.
Saturday, August 09, 2014
Remember the boombox? Well I picked one up at a yard sale today. I’d been looking for a cheap but relatively good quality one for a while so that I could play content from my MP3 player or tablet while in the shower.
The one hitch? It didn’t have an auxiliary or CD input. So I did a Google search for “convert boombox mp3” (not in quotes…) and found a few good sites. The one that had the best advice was this guide to “Installing an Auxiliary input on any Stereo”. The basic technique is to find the input to the amplifier and graft the auxiliary input to it while disconnecting the other inputs. I cracked it open. Quick tip: first remove every knob you can, then remove the screws and it should come apart easily. This is my candidate for getting the sound in. That’s the radio board. I’ll snip those wires (the boombox will not have radio or cassette function because it’ll be a pain to keep those as well.) The cassette assembly also needs some trimming. I removed the whole motor assembly on the left and the majority of the gears, belts, etc. The aerial clamp isn’t needed. The power (L) and speaker (R) connectors. Now I try and figure out what those 5 wires from the radio board are. Yay, ground. And a 5V DC line. It will be removed from the connector. Ground and stereo left and right hooked into a 1/8” audio cable for testing. I could just reassemble it without the other two boards but will need them for cosmetic reasons. Some splicing, soldering and insulating of a new 1/8” cable to amplifier board cable. After getting it all back together (with neither the cassette or radio board hooked up, but in place) I was able to play some tunes from my MP3 player. I can stow the cord in the cassette tray. And it pops open for use.
Wednesday, July 09, 2014
I don’t think this was meant to be a precision reference, although I may be wrong. I could play with the internal potentiometer I suppose. Anyway, a neat thing.