Building 1350mm x 2000mm CNC Table. Duet or?



  • So as the title states I am planning on building a larger CNC table. Would like to use NEMA23 for X and Y, and a Nema 17 for Z, although the current design is made with all NEMA 17's, but if it runs off of NEMA 17s I will keep it that way.

    I love my duets for my printers, but I am getting mixed results for the duet with CNC. I did see new UI's for the web interface that are more adapted to CNC which is great, but Also how the Duet steppers cannot keep with certain harmonics?

    What other options are out there that are similar to Duet? I love Duet's simplicity (macros, config.g, etc) and workflow (upload file over wifi, hit start, or walk over and start via touchscreen) but not sure what others can do this. I need to this to be a standalone system, not needed to be connected to a PC to run.

    The Duet 3 is just too expensive for what I am trying to go after now. I can justify a Duet 2 Wifi as I would like to replace the hacked up 2+ year old unit in my main 3D printer. But driving NEMA23's may be a challenge.

    Recommendations from experienced users?

    Lastly, is there any documentation on Duet with a CNC? I haven't been able to find anything of the sort so far with a Duet wifi or ethernet.



  • I have a 600 by 1500 mm by about 125mm Z CNC Router. It has had several different controllers in its history. I use it a LOT.

    At this moment, I'm running a "Planet CNC" controller, with Gecko Drivers and Nema 23s.

    The PlanetCNC board is imbedded in the Machine, and has step/dir outputs for external drivers, has endstop inputs, etc, etc, etc. You connect to this board a User Interface. That UI can run on a Windows, Linux PC, and can also run on a Raspberry Pi. That's how I choose to implement it: Screen, keyboard, mouse and R Pi. I do recommend a Pi4, the Pi 3B+ has very subtle USB issues (that affect much more than just Planet CNC).

    I'm very happy with it at this point in time.



  • @Danal So this board is a control board without steppers; in a sense connects all the I/O and need a Pi to connect via control? Interesting. I think I found there site.

    Are there any US based retailers? Would like to build up a BOM for this. I saw someone else comment a few days ago about Planet CNC with good feedback.



  • Im just receiving my power cord today to run a spindle for my 4’x8’ CNC I just made. I’m using a Duet 3. In hind sight I maybe would have also gone with the duet 2 wifi and then just added the required drivers to run all of my nema23 motors including the high torque one on my z. It probably would have been more cost effective because I also wanted the wifi and to get that with the duet 3 you need a raspberry pi or SBC. Either way the duet is absolutely the way to go. Love the interface and the help and support in these forums. Guys have been super patient and helpful getting things working.



  • @Fickert +1 on the planetCNC, it is one of the best options for what you are doing.



  • @Fickert said in Building 1350mm x 2000mm CNC Table. Duet or?:

    @Danal So this board is a control board without steppers; in a sense connects all the I/O and need a Pi to connect via control? Interesting. I think I found there site.

    Yes.

    Although I would change the phrasing a tiny bit. There are several boards (TinyG, PlanetCNC, GRBL) where the controller board is "in the machine" and the User Interface is separate. Some of these have small drivers. All of them are quite often used with external drivers (for anything larger than a desktop machine).

    These boards perform the G-Code interpretation. Specifically, the motion planner is on the board (not the UI PC).

    Duet also fits on this list: It has drivers, and Duet 2 is easy to use with external drivers.

    For at least a couple of these (TinyG, GRBL), there are even multiple User Interfaces. My CNC router ran TinyG for a while, with two different UIs, running on cheap "corporate lease return" PCs that I'd buy from refurb places for around $100 US. Eventually, dust kills these... Therefore, running any board with a totally fanless computer for the UI, one that only costs $40 or so, that is very attractive.

    TinyG is open source software on a board you can (still) buy... but development essentially stopped a few years back and you have to live with the bugs that it has.

    GRBL is open source... and has some many, many, variants... and a bunch of different boards on which it can run... and is too chaotic for me.

    PlanetCNC is closed... and I prefer open... at the same time, they "just work".

    Duet is open and runs on a board you can buy... and has a GREAT developer and community support; nonetheless, its real focus is 3D printing and the web interface reflects that.

    Of course you can absolutely run a Duet in CNC mode. The pros/cons of that have been widely discussed on this forum, search (particularly use advanced search with the time set to the last six months or so).



  • I think It would be a good idea if a Duet3 CNC oriented board came out. RRF is great, and very easy to use, but as mentioned before all the boards are very 3D printer oriented.
    I would like to have a Duet3 without drivers, thermistor inputs and heater outputs and instead have dir/step outputs and ethercat for the use of industrial servos. Another missing feature is an encoder input for a spindle, needed to do hard threading, and an addon board with isolated inputs and outputs needed for a CNC. Also an MPG input.
    Software side, there are no fixed cycles (for now at least), which is not very necessary for a mill (or a router), except for drilling cycles, but it is really used on lathes, also tool radius compensation is needed for a lathe. Otherwise, everything needs to be done on CAM.


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