Just before the virus responses kicked into full gear I added a tool to the wood shop. A gantry style CNC router. After a fair amount of research I purchased a Shapeoko XL from Carbide 3D. All of these systems involve the hardware, software to create the patterns and another piece of software to send the appropriate instructions to the machine.
Contributed by Bill Tumbleson
Hardware comes down to a frame to support the carriage /router, a drive mechanism to move the carriage /router in three axis (left/right – forward/backward – up/down) and a motor to spin the bits.
Drives are belts or lead screws moved by stepper or servo motors. A dedicated motor (spindle) or a trim router are the options for spinning the bits. Cost kept me in the belt / stepper motor and trim router package although I did spring for a lead screw for the vertical motion. The rigidity of the frame is also critical and the Carbide 3D machines are very substantial and well made.
The size of the unit was dictated by available space. The Shapeoko XL has a working surface of 31” x 15”. In addition to the CNC router space is also needed for a computer, various accessories and dust collection. All fit nicely into my old basement office.The software for these machines are another piece of the puzzle. Typically when you look for advice on what is needed the answer is vague, very vague. As in“There are lots of choices just pick the one you need”. This advice is not very useful because you don't know what you need. This ambitiousness is what lead me to choose the Shapeoko as it comes with the needed software. It is admittedly basic without all the bells and whistles of more complex (and sometimes expensive) packages. Also the software was not Internet based which was a very important criteria for me.
An active on-line forum for this machine has proved useful as I stumbled my way into the machine's setup and use.I ordered the system on a Friday and it arrived the following Tuesday. It came about 70% pre-assembled. Directions were accurate and detailed except that I had upgraded to a lead screw for the vertical axis and this involved jumping between two sets of documentation which caused some additional head scratching. I was successful in getting it together and running a test using a magic marker instead of a bit to create a drawing. There were no missing or broken parts and no smoke. Learning to actually draw something, create the tool paths to cut it out and getting the settings correct for the material being used proved a bit more challenging. Truth is figuring out this will probably never end. I downloaded a couple patterns from a website and cut them out successfully. However when I tried modifying one of these files and used my own settings things got more 'interesting' as you can see in the photo. The result on the right is what Jerry Carpenter very diplomatically referred to as 'Creative Programming Skills”. In other words a screw up. Litterally as the bit came out of the collet and started to bury itself in the wasteboard before I could hit the 'off' button.
More practice, reading and watching the simulations before actually running the job have produced a usable result – albeit a very simple project. See ornament photos. And learn to check and double check your settings. And make sure your work piece is clamped securely – from ALL sides and top !! The dang machine will actually do what you instruct it to even if it is obviously not correct. So that has been keeping me occupied. I will eventually get this stuff figured out
unless as one gentleman on the Carbide 3D forum said “I throw it out the back patio door, light it on fire and drive over it with an excavator”. Fortunately I am certain it will not come to that – I don't own an excavator.