[Peter] has been having some positional repeatability problems with his CNC3020 Router recently. The problem was mostly in the Z axis and was measured to be up to 0.3mm off position after 10cm of travel. This may not seem like a lot but it was enough to break a few 1mm diameter end mills. The X and Y axes generally seemed OK. Surfing the ‘net reveled that the control board’s power rails did not have any filtering capacitors and that may have been the cause of the problems. Unfortunately, the positioning problem still persisted even after the cap’s were added. Frustrated, [Peter] then started a full-blown investigation to figure out why his Z axis wasn’t cutting the mustard.
In a CNC system there are 2 major components, the electronics and the physical machine. Since it was unknown which portion of the system contained the problem, [Peter] decided to quickly swap the X and Z channels, running the Z axis with the X axis electronics. The problem was still evident on the Z axis which means that there is something wrong in the mechanics of the machine. The Z electronics were put back on the Z axis and the testing continued by lowering the acceleration and the maximum speed. The positioning error was still there. Since it is possible that the Z motor could be the problem, it was decided to swap the X and Z motors but midway through the process the problem became evident. When trying to rotate the Z axis lead screw by hand there was a noticeable lack of smoothness and the axis seemed to jump around a bunch!
Continue reading “A Little Lubricant Goes A Long Way…. With Your CNC Machine”
[Vegard] and his wife were expecting a baby girl, and decided to build a castle for their new daughter. As a prototyping geek with his own CNC machine in his apartment, he decided to take to Google Sketchup to design this well-crafted castle decoration for his daughter’s room.
The first challenge was figuring out what the castle would look like. [Vegard] had never been to Disney Land or World, and so had never actually seen any of the fairy-tale castles in real life. After experimenting with some paper versions, he settled on a design which incorporates multiple layers and can house lights within them.
The next step was to cut the final version on the CNC machine, then sand and paint the parts. After figuring out a way to mount the castle to the wall, some LEDs were added for effect, driven by an Arduino. The final version looks pretty good!
Hacking your kids’ room is great fun, and you get to keep making new stuff to remain age appropriate. We bet [Vegard] can’t wait until she’s old enough to enjoy a marble-run that wraps the entire room. In the mean time he can work on a classic robot stroller.
[Enzo] wrote in to tell us about his recently completed CNC Router (translated). This is an excellent high-quality, all-aluminum build with no cut corners. The work envelope is a respectable 340 by 420 mm with 80 mm in the Z direction. Linear ball bearings make for smooth travel and lead screws with both axial and radial bearings give a solid foundation of accurate and repeatable movements.
We’ve had a bunch of CNC Router projects on Hackaday in the past, including other nicely made aluminum ones, but [Enzo] is the only one who spent just as much effort on his computer and machine control system as he did on the CNC machine itself. The computer, which is running Windows and Mach3, is an all-in-one style build that starts out with an old LCD screen from a broken laptop. Along with the reused screen, a very small ETX form factor motherboard was stuffed inside a custom made plexiglass enclosure. A Compact Flash card handles the storage requirements.
Underneath the monitor is another great looking custom made enclosure which houses the stepper motor drivers. There are 3 switches on the front panel to send main’s power out to the PC, spindle and an AUX for future use. On the back panel there are D-sub connectors for each stepper motor, the limit switches and the PC connection. Oh yeah, by the way [Enzo] designed his own bipolar motor drivers (translated) and sent the design out for fabrication. These boards use an A4989 IC and mosfets to control the motors. The schematics are on his site in case you’d like to make some yourself.
Continue reading “Super Nice CNC Router Build Leaves Little To Be Desired”
Brushless DC motors are common place in RC Vehicles. They are small, light, fast and can be inexpensive. [Raynerd] wanted a new spindle for his CNC machine and thought that a brushless DC motor would be a great platform to build from.
[Raynerd] started with an off the shelf motor that had an 8mm shaft. This shaft size was important because the motor shaft was to be replaced with an ER16 collet arbor of the same size. A collet is a device used to hold cutting tools by collapsing a segmented ring around the tool. Collets allows for quick tool changes while providing a strong clamping force. ER16 is a designation of one of many collet standards.
The main housing was machined out of aluminum specifically for this project. This housing holds two radial load ball bearings that support the new rotating collet arbor. There’s another bearing in this assembly, a thrust washer this time, that keeps the arbor from moving axially in the housing.
The 12 volt output of a standard ATX power supply was used to power the system for testing purposes. A general RC Vehicle electronic speed control and a servo tester work in conjunction to manually regulate the spindle speed. Check out the bench test video and an exploded photo after the break.
Continue reading “Brushless DC Motor Used For High Speed CNC Spindle”
Hallo iedereen! All the way from the Netherlands comes this fairly unique CNC milling machine built by a handful of Mechanical Engineering students over at the Delft University of Technology. These guys only had one week to build the mill in order to fulfill a requirement of their Mechtronics class. Unfortunately, directly after showing the machine worked, it had to be disassembled.
If the frame looks a little toy-ish, it’s because it is. This particular system is called Fischertechnik and the main support beams are similar to that of aluminum extrusion (ex 80/20, Misumi) except that it is made from nylon. Notice the extremely long cutting bit and comparatively abnormal large Z axis travel capability. What this system lacks in rigidity is made up by being able to carve a very 3D shape with steep sides without the machine hitting the work piece. The loss of rigidity was totally acceptable since the team was only planning on cutting foam and the project’s purpose was to learn mechanics and automation.
Continue reading “Fischertechnik CNC Machine Looks Innocent Whilst Cutting Your Face”
Milling and routing flat surfaces is pretty much the point of a CNC router, but how about curved surfaces? Auto leveling of hobby CNC machines and 3D printers is becoming commonplace, but Scorch Works is doing just the opposite: using a probe touch probe on a CNC machine to transform a G-Code file into something that can be milled on a curved surface.
The technique is pretty much the complete opposite of Autoleveller, the tool of choice for milling and routing objects that aren’t completely flat or perpendicular to the bed with a MACH3 or LinuxCNC machine. In this case, a touch probe attached to the router scans a curved part, applies bilinear interpolation to a G-Code file, and then starts machining.
The probe can be used on just about anything – in the videos below, you can see a perfect engraving in a block of plastic that’s about 30 degrees off perpendicular to the bed, letters carved in a baseball bat, and a guaranteed way to get your project featured on Hackaday.
Continue reading “Milling Curved Objects With A G-Code Ripper”
Stepper motors are great for a bunch of projects; CNC machines, clocks or robots for example. Sometimes when working on a project that does include a stepper motor and driver, it would be nice to test that part of the build without hooking everything up. A pulse generator could be used to complete such a task and [CuteMinds] has put together a DIY friendly version tailored specifically for stepper motors. This device makes quick and easy work for testing out those stepper motors.
At the heart of the pulse generator is a 12F675 microchip which looks to the resistance value of a potentiometer to adjust the square wave step signal output from 20hz to 3khz. Just having the step signal would pretty cool but this project goes a little farther. There are 3 sets of headers on the board that allow you to connect either a jumper or switch in order to: 1) turn the power on, 2) enable the stepper driver and 3) select the direction the motor turns. The on-board batteries make this unit portable for remote usage.
If you are itching to make one for yourself, the Eagle schematic and board files are available for download at the above link.