Salvage Surface Mount Switches For Homing Test

After I managed to destroy a stepper motor during experimentation, Emily graciously donated another one to the cause. Hooking it up to my A4988 test board, I can tell this optical drive carriage had more power than the one I salvaged from a laptop drive. At least this one could win a fight against gravity. However, I was dismayed to find it is still quite weak in absolute terms, and this time I’m wary of cranking up the power in fear of destroying another motor.

So in order to set up something to learn how to wire up a homing switch for Grbl, I need to find switches that take less force to activate than the switches I already have on hand. Where might I find tiny switches that take tiny force to activate? The recently disassembled laptop optical drive!

SMD switches

Its control board had a few tiny surface mount switches. They were connected to small mechanical linkages throughout the drive so this control board can determine various states of the eject mechanism and such. There were a total of four switches and I put them under a heat gun in an effort to remove them.

This was a tricky procedure, as I had to melt the solder without melting the plastic. I put too much heat into two of the switches and destroyed them in the process. Fortunately, two of them were removed relatively undamaged. I put one of them under a meter to check for continuity, and it appeared to still work as a switch.

And soon, if all goes well, it will be a homing switch.

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