That, dear readers, is the smell of a new Hackspace opening up in Davenport Iowa. It is also the lovely scent of burning plastic. Because how do you celebrate a new Hackerspace? By casting bronze coins of course!

Begin by having a MakerBot extrude plastic coins, then compact the plastic coin in sand to produce a mold. Heat up your bronze in a trashcan furnace and pour it into the mold. The plastic melts away and you’re left with a bronze coin.

There are probably some safety measures and precautions that should be followed as well…

The days of plugging coins into a stand up arcade game are sadly dwindling. [Dirk] figured out a way to prolong the nostalgia by incorporating currency back into the experience in a useful way. He rebuilt the video game Raiden to pay out a prize when you win the game. Now it takes a coin for each play but if you make it to the end you can recoup the expense.

[Dirk] took an original cabinet game, did some dangerous work to replace the old CRT monitor, and retrofit a MAME machine to handle the gaming. He’s using Windows and had some problems because of it but, as you can see after the break, things worked out in the end. The hopper hardware that spits out coins went through several steps from the initial design to the finished product, but it has always been based around a PIC controller connected to the MAME box via parallel port. This is a fun addition to any MAME cabinet.

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[tvst] has an interesting take on a sequencer. His design uses coins on a turn table to trigger midi events in a loop. There are four tracks available, each having its own sensor above the spinning platform. The sensors consist of an IR transmitter and receiver setup as a voltage divider. When something passes below the IR transmitter and reflects the infrared waves back up to the receiver, the output of the sensor moves to digital high. The four sensors are connected to an Arduino which is used in conjunction with ttymidi, which converts the Arduino data into midi events.

We like projects that provide a more tangible interface for the user. Coins work well for this setup. They reflect infrared enough to trigger the sensors, and they’re easy to pick up and move without upsetting the rest of the tracks. It would be great if this could be expanded to differentiate between coins (pennies versus dimes, etc.) in order to increase the resolution from four different events to eight or more. Check out the video after the break. Read the rest of this entry »

[Mike] sent in this project. It’s a robot, designed to print on wooden coins while people watch. It was built to be in the iHobby Expo 08 in Chicago. The main movement is controlled by a BASIC Stamp2, while the ink jet system is run off of a Propeller. The entire system has 4 servos, 3 stepper motors, a DC motor, a hacked breast pump, an ink jet head, and 5 IR sensors. in case you missed that, it has a breast pump. We’re assuming that’s the part that picks up the wooden nickels with suction. He states that the project was meant to be entertaining, so there are lots of superfluous and inefficient actions as you can see in the video after the break. Great job [Mike].

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This is a 5 cent tilt sensor. We know it cost more than 5 cents, but it is in fact a tilt sensor that utilizes a 5 cent coin. We’ve all done quick hacks to make quick sensors for various projects. We’ve seen tons of them, from stealing springs out of pens and shoving a resistor through them for flexible contact switches, to tin foil touch sensors. This one is new to us though. The design is fairly simple, you insert 4 bits of wire to serve as contacts and the coin will make contact with only two at a time. It isn’t analog, it isn’t extremely precise, but it is super quick and easy. Thanks for sharing [ix].