Anet A8 CNC Flex Shaft Mount by 3D_Pressure

Last crawled date: 3 years, 1 month ago

A mount to convert you Anet A8 to a light duty CNC Router.
What parts do you need for this conversion?
An Anet A8
Rotary Tool including Flex Shaft
Mill Bits (Update: I changed to these Mill Bits which work better).
This Mount (three parts, each printed once)
four M3 Screws and Nuts
How do you mount this holder?
You'll need to remove the complete hotend from your printer. Just unscrew the the mount screw below the carriage, loosen the nut on the heat break, and slide it out. You also want to remove the cooling fan, just unscrew the two screws holding it on the carriage. You don't need to unplug the hotend, as your printer might complain if you do.
Clamp the end of the flex shaft into the holder, using the M3 screws and nuts and the printed parts.
Now install the holder onto the x-carriage. Remove the six screws on the left half of the carriage, put the holder in its position and use the screws to fix it there. Be sure to already have the end of the flex shaft clamped to the holder before installing the holder on the carriage.
How do I slice parts for CNC machining?
Obviously we are not going to slice parts, but calculating a toolpath instead. In the end both will give us .gcode files that our printer can process. I am using Fusion 360 to create my gcode files, there is a CAM tab dedicated to do so. This requires a postprocessor, thanks to Tech2C for sharing this one that works just fine for my Anet A8. You'll find a lot of tutorials on how to create a toolpath within Fusion 360, so I won't cover it here in detail. If you got any questions, feel free to ask them.
Be sure to set the horizontal movement speed and the ramp step size to resonable low numbers, as your printers frame is not as stiff as a dedicated CNC Router. I've been using 5mm/s (which is obviously way slower than what you are used to while printing!) and a "layer depth" of 0.5mm. You can easily enforce using small depth steps by telling fusion that the length of the cutting blade of your tool is e.g. only 1mm.
Notes about the acual milling process
Put something in between the material you are procesing and your print bed. You don't want to mill your print bed away, do you? I've been clamping the wood I wanted to process above a 1cm plank to protect my print bed.
I've only been testing wood so far, milling plastic should be fine, too. I can't tell whether milling of aluminium is possible, but I'd not count on it. I'll be trying to create a PCB, and let you know how it worked out.
Do a dry run before starting your first milling task.
Milling is quite noisy. And it also produces loads of wood dust, be prepared to handle it ;-)
Is it possible to use another rotary tool?
Sure, you may use any dremel you got your hands on. I like having the flex shaft, as it will reduce the weight on the carriage. If you need the clamps having a different size (for this shaft I needed Ø20mm on the bottom, and Ø15mm on the top clamp) just leave me a note, I can fairly easy change their sizes.
This tutorial shows a conversion using another mount and printer, but it may help you in converting your Anet A8, too.
Any kind of feedback is, as always, very welcome.