Rube-Goldberg provides liquid refreshment


The image to the left doesn’t make this look like much, but inside of the cardboard vending machine lives a clever Rube-Goldberg device. The video after the break gives a look at the inner workings to show how a quarter manages to dispense a full can of Coke. But that’s about all the detail we get on the project.

There are two sets of counterweights used in the design. Some marbles, and what look like giant pinballs. The coin chute, located on the left side of the venting machine, funnels the money into the waiting marble. When the marble rolls off it lands on a spoon. The weight rotates the spoon-filled disk and causes one of the waiting pinballs to drop from their rack. As that metal ball falls it operates a ratcheting system to dispense just one can. It looks like the capacity of the machine is limited to two refreshing cans of sugary liquid, but that could be scaled up if more room were made for cans and counterweights alike.

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Via press crushes copper to make a mechanical connection


[Jay] was looking for a way to make his own vias on homemade double-sided PCBs when he stumbled across this post from about five years ago. The technique shown here makes mechanical vias and was developed by [Retromaster]. There’s no soldering involved, instead he uses some solid core copper wire and a press to crush it tightly against the board.

The press is made from aluminum stock, with a couple of plates of stainless steel which come in contact with the board. The aluminum stock is easy to work with, but it’s relatively soft which is the reason for the addition of steel. He uses copper wire which already fits tightly in the hole through the substrate. After clipping off the excess as near to the board as possible a trip through the press leaves each side flat as shown in the inset image.

We looked through some of the other projects we’ve seen from [Retromaster] like the Atari 2600 in an FPGA and this emulated Amiga floppy drive. But we didn’t see any diy boards where he used this crushing technique.