Hacking a SX2 Mini mill

SX2/CN2 tachometer kit in action
SX2/CN2 tachometer kit in action

I picked up a SX2 Mini mill recently via Little Machine Shop (They call it the HiTorque Mini Mill 3900). When I received it, I noticed there was a port for a digital tachometer readout on the side of it. I though this might be useful, but felt 125$+ for it was a little excessive for what it was. Atop of this, they were out of stock.

I ended up reverse engineering the protocol, building some less expensive kits, and documented how exactly I figured out the protocol. Along the way, I also discovered how to make the mill run in reverse!

If you wondered how a reverse-engineering problem like this is approached or what tools are used, this could be an interesting read:


CNC User Group Wrap-Up

We hosted our first CNC/Makerbot User Group meeting. A special thanks goes out to Brian Dolge for organizing the event and making it a success. We had a great turnout with about 20+ people in attendance. Marty McGuire demonstrated his Makerbot by drawing on Post-Its with a Sharpie. Harford Hackerspace demonstrated their CNC Milling machine by cutting out a wooden Ninja star. Check out the images below.

CNC v1.5 revision update

We are currently in the process of revising our CNC design since the Y/Z axis was eating its rails over time due to slight alignment issues.  We decided to upgrade the bearings in general to avoid the problem in the future.  The x-axis seems to be working fine, so we are going to leave it alone for now.   The revision includes CNC cut pieces instead of hand cut pieces (using table saws and drill presses).   We also did a major upgrade to the bearings and went with ACME-type lead screws to minimize backlash and improve accuracy.  We updated the stepper couplings to the lead screws to make future maintenance easier.  The redesign is expected to be complete within the month.

Our CNC Can Kick Your CNC’s Butt!

This video is in response to the one posted here, where a Mr. Riley Porter moves a 35 pound dumbbell with his CNC.  We decided to try to trump his CNC’s weight-moving ability by pushing our machine to lift and move first 45, then 55 and finally 65 pounds!  We wanted to continue with the weight increases, but did not have a safe way to attach more weight to the Z-axis assembly.  Our CNC build is turning out to be quite the beast.  Now all it needs is a catchy name…