I’ve had a CNC mill for a few years now, and while many homemade CNC mills use EasyDriver or Pololu, mine came with a sturdy, generic TB6560 controller board. For those unfamiliar, boards like this are interfaced using an old fashioned LPT parallel port, which was initially an annoyance, but quickly became impractical and a hassle, having to use an old PC with VNC installed. The board has plenty of power to push the steppers around, far more than any of the smaller / cheaper solutions had to offer I think, so I wanted to try and teach this board a few new tricks, and let me interface with it using a more modern interface.
Tag Archives: CNC
I found it a little annoying whenever I wanted to swap the motor mount off my Zen Toolworks CNC mill, the washers and nuts would be difficult to work with and regularly fall into the machine. I already super glued most of the washers to the mill, but to improve swapping accessories, I cut these little jigs out of 4mm acrylic to hold the bolts from turning. The photo below shows the jigs with the nuts not inserted yet. Once the mill is reassembled, I only need to deal with the accessory I am attaching, and the four bolts used to hold it down. Much easier!
I bought a Roland blade holder on eBay, which is mean to be placed in a pen plotter. People have had good results in using it in their CNC mills. I found a number of photos of other setups, but they were either attached with no spring pressure, or far too over engineered. Since I want to play with laser cutting later, I made the assembly hold both laser and blade cutter. The assembly created in Google SketchUp, exported into CamBam, then was cut out of ~4mm thick cast acrylic using the CNC mill. The assembly replaces the motor mount on the CNC.
To properly cut, the blade has to have some spring loaded pressure into the rear of the blade holder. This allows the blade to float across the work surface with a constant amount of pressure. There were a lot of ideas on how to do this on the internet, but I came up with a cheap quick solution by reusing parts from two ball point pens. So far, the results have been great! I zero the Z axis with the blade just touching the vinyl, then cut at -0.3mm.
The Zen Toolworks 7×7 is my first CNC mill, and while jogging around the mill, I felt the stepper motors could run a bit quieter. If you were to operate one while it was unscrewed from the machine, you would notice it is significantly quieter. I read that you could purchase cork gadgets to sandwich between the motor and the frame. I found them on eBay, but I felt it wouldn’t differ much from cheap craft foam.
Like the BusPirate case I recently made, I have a lot of these PCBs that are fragile and I worry will be damaged by every day use, and even storage in my drawers. I went with a slightly thinner cast acrylic and included a few new concepts in the design. First, I used a v-carve bit and engraved writing into the case front. While it is ledgible, I think it would have been better if I had carved into backside of the top piece. Second, on the bottom section, I made recessed cutouts as so the board can sit flat on the bottom of the case. Lastly, I used holding tabs on the two middle sections, as so they stay put while the cutting is happening. On the BusPirate mill, the middle “C” parts were moving around due to their flimsy shape. I’ve updated the files to reflect my adjustments and observations in the case I already milled which is pictured. If I decide to re-mill it, it should fit much better and look better.
I love my BusPirate v3, it’s constantly in use. However, the device comes with no case, and is sold as a populated PCB, and offers no protection. I’ve seen other cases on the DangerousPrototypes website submitted by other users, and I thought this would make a great first project for my CNC machine.
I have been looking at zentoolworks 7×7 CNC mill for the last year, last week one showed up on eBay and I got it, so awesome. I just finished reassembling and hooking up all the electronics, and I can’t wait to learn more about using it. Since the TB5650 Stepper driver board uses a Parallel port, I am setting up an older laptop with windows and Ubuntu dual boot to play with all the applications available.
First impressions are that the quality of this device seems really nice and sturdy. The Stepper driver board and the spindle motor controller both are lacking proper labeling on the PCB in English, but after an hour of testing pins, I’ve figured out most of headers. The DC spindle motor is really quiet, which is amazing to anyone who’s ever used a dremel.
In the next few days I’m going to try and attach a felt pen in place of the cutting blade to get the hang of processing gcode.
Uses for the CNC machine I can see in the near future:
- Prototype PCB boards quickly, exported from EaglePCB
- Make some fancy engraved labels for things around my family’s ranch
- Attach a burning laser diode that I bought a while ago, and make some stencils
- Design some things in Google Sketchup and export them into the real world.
- Make some plexiglass enclosures for some electronic projects I’ve had in the past
- Purchase a drag-knife head and cut some vinyl stickers
Photos and more to come!