Adding A Tachometer To The SX2 Mini Mill

sx2_mill_tach

[Jeff] recently bought an SX2 mini milling machine with plans to eventually automate it for use as a CNC mill. After paying nearly $700 for the mill, he decided there was no way he was willing to pay for the $125 tachometer add on as well. Instead, he reverse-engineered the mill and constructed a tachometer of his own.

He opened the control box and started looking around. After identifying most of the components, he got sidetracked by a 3-pin header that didn’t seem to have any particular function. That is, until he realized that a lathe by the same manufacturer uses the same components, and figured that the header might be used for reversing the motor. Sure enough he was right, and after adding a reverse switch, he got back to business.

He probed the 7-pin socket with his logic analyzer and quickly picked out the mill’s data line. He hooked the line up to an Arduino and in no time had the RPM displayed on an LCD screen.

[Jeff] says that this little experiment is the first of many, since the mill is so hacker friendly. We definitely look forward to seeing a CNC conversion tutorial in the near future.

CPU Tachometer

[youtube=http://www.youtube.com/watch?v=3nAeftaUWYw]

Recently, analog displays have come back in vogue. This is partially due to the common steam punk theme that is popular right now. [Cristiano] has done an analog display, but instead of brass and polished wood, he’s gone automotive themed (Internet Archive Cache) with it. He purchased a cheap tachometer from ebay.  A circuit had to be designed to give the tach the signals needed for it to operate, and you can download the schematic from his site. As you can see in the video above, it works well. We think that “shift” light might get annoying pretty quickly.

Bluetooth Motorcycle Control Panel With Arduino

Motorcycle_in_neutral

[Bill2009] has made some nice progress on a control panel for his motorcycle over at the arduino.cc forums.  It can show speed, tachometer readings for the wheel and engine, as well as indicate the current gear. He reads the square wave coming off of his tachometer input and pulses from a reed switch mounted on the wheel to calculate all this. To top it all off he can monitor the data via a Bluetooth module attached to the board, which is much better than trying to balance a laptop on your knees while cruising down the highway.  He is working on getting the size down so that he can mount the whole assembly inside of his motorcycle. He also plans to add new software features like wind resistance calculations and0 to 60mph timing.