CNC3-3018 Pro
This page is still work in progress.
As I've mentioned in the blog post about this machine, I ordered this hobby (or as serious hobbyists will say: toy) grade CNC machine from Amazon (DE) seller craftsman168 on 2019-09-05 for 182,77 EUR. I had seen similar machines for a while and had noticed this upgraded version on one of the big Chinese retail sites a day or two before for about 20 EUR less.
Being able to have it shipped directly from Amazon instead of waiting for a month, not having to deal with customs and not pay extra tax and fees (which would add up to even more), made it an easy choice to order there and then.
Since there are different clones with minor difference out there, I am listing the details on my machine here:
- Work area: 300 x 180 x 45 mm
- Dimensions: 400 x 330 x 240 mm
- Supported systems: It's all based on open source, so there will be tools for all types of systems. I will be running it mostly with MacOS and Linux. Listed systems were Windows XP, Win 7, Win 8 and Win 10.
- Use cases: Engrave and cut plastics, wood, acrylics, PVC, PCB, soft aluminium and similar materials, but not hard metals, jade or other hard materials.
The kit includes:
- all parts for the engraving machine frame consisting of
- 20x20 and 20x40 aluminium extrusions,
- "Bakelite" plates (it might be some kind of phenolic resin, but I am not sure if it was translated correctly)
- screws, nuts and tools to tighten them
- Z and Y axis and spindle mounts
- linear rods and bearings
- lead screws for the linear motion
- three NEMA 34 stepper motors, 1.33 A, 0.25 Nm torque at 12 V.
- Woodpecker CNC 3.3 control board running GRBL Grbl 1.1f. This board seems to be very similar - if not identical - to Camtool CNC v3.3 boards that come with similar machines. ((FIXME stepper drivers?))
- 775 DC motor (12-36 V) as spindle running at 24 V with ~10.000 RPM, rated power: 60 W, maximum power: 120 W
- ER11-A collet chuck with a 3.175 mm collet pre-mounted on the motor shaft
- offline-Controller allows to control the machine directly and send files from an SD card
- plate clamps to hold material from 0 to 30 mm thickness; 50 x 20 x 3 mm with a 6 mm slot
- ten engraving bits 0.1 mm diameter, 20 °, shaft diameter: 3.175 mm
- 24 V, 5.6 A power supply
Remarks
- Always get a model with a pre-mounted ER11 collet chuck / extension rod! There are clones with a really bad tool holder or where you have to mount the ER11 yourself by heating up the extension rod and hammering it on the motor shaft while making sure it is mounted true and centered.
- People always say that the Z-axis mounts are 3D printed, but it doesn't look or feel like a typical printed part. It might be extruded or is a material I am not experienced with - nylon perhaps?
- For the spindle motor I've seen these specifications: 3000 RPM at 12 V, 7000 RPM at 24 V, 9000 RPM at 36 V.
- You will probably only use the offline controller once, because it can not be used together with USB and it is really fiddly to operate.
The Pro version is easier to built than the older one. Because all the holes are pre-drilled there is a lot less positioning / calibrating / squaring to do and results in a higher accuracy. The base frame is 2 cm higher which makes it more stable too. Overall the whole frame seems to be more rigid than the older version.
Build
There is not much to say about the build. It was pretty easy to put together the basic frame and the electronics. The manual is basic, but ok and guides through all steps with pictures. There is also a lot of videos available online showing the process.
It doesn't go beyond the basic build though. After that you still have to figure out what software to use, spindle speeds and feeds for different materials, even how to mount materials properly. But I expected this as a part of the pretty steep CNC learning curve anyway.
((FIXME: add manual)
Upgrades
- sacrificial bed holders
TODO
- limit switches / end stops
- fan for the stepper motor drivers
- dust collection
- case
- Upgrade GRBL
- back plate?