Hacking a Brother thermal printer to use non-OEM continuous rolls

You can get your hands on a Brother thermal label printer for $65-75. But if you don’t want to buy the Brother branded continuous feed paper for it you’re out of luck. Unless you pull off this hack which lets you use any thermal paper you want with a Brother QL-500 printer.

The printer is tied to the OEM paper because of a pattern printed on the back of the roll. It’s basically an encoder strip made up of black rectangles spaced at regular intervals. Surely there are other brands that come with this pattern on them, but if you want to use paper without it the secret is in moving the sensor that reads that strip.

The brilliant solution is to use one of the white feed-gears as an encoder wheel. [CheapSkateVideo] used a magic marker to paint two opposite quarters of the gear black. He then removed the optical sensor and placed it on the side of the case facing the wheel. It needs to be adjusted along the radius of that gear until the timing is just right, but once it is you’re ready to go. The sensor is a safety feature to ensure there is media in the printer. If there’s not you can burn up the print head so keep that in mind. See the explanation in the video after the break.

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Knitting machine hack by keypad emulation

[Travis Goodspeed] and Hackaday alum [Fabienne Serriere] joined forces to develop an alternative interface for a knitting machine. They’re working with the Brother KH-930E machine. We saw [Becky Stern] use the same model by manipulating data on an emulated floppy drive for the device. [Travis] and [Fabienne] went a different route, and are emulating the keypad using an Arduino and a set of transistors.

They started by reverse engineering the keypad matrix using a continuity tester. Once they worked out the column and row layout they connected each to an NPN transistor. The Arduino sketch simulates button presses to set knitting bits for each row, with just one reset button for user input. This can be used to send data from a PC, or as a standalone system. Either way, it’s not only a great way to add functionality to the kitting machine, but a good example of how to interface with the keypad on just about any device.