Just a quick short update about the corexy. The little motor I was planning to use for the toolchanging mechanism just didn’t have enough torque.

I have now moved to a mechanism inspired by the Jubilee printer. I’ve remixed it slightly and used bike brake cables instead and my own design of parts.

Above is just a short video showing it able to lock and unlock a tool.

I’m pretty much stuck now until my expansion board comes.

It lives …. kinda.

I have it moving in X and Y. The belts haven’t been tightened correctly yet and I had to add some additional strength to a couple of parts but all in all I am happy so far.

Still waiting on the following:

  • Bed
  • Lead Screws
  • Couplers
  • Duet 3 Expansion Board
  • Locking Pin – I am making this myself

My early christmas present has come in the form of a shiney new Duet 3 board. Those of you who have read my earlier posts know that I have used Duet 2 ethernet boards (although they were clones) on both the Anycubic Linear Plus and the Anycubic Predator. They are a fantastic board for the money so it made sense to look towards the duet family for my new corexy.

But why did I choose the duet 3 over the duet 2? Well there are a number of reasons why I have done so.

  • The duet 2 tops out at 10 drivers (duet 2 + duex5). If I populate my corexy with all tools, I would need 12 drivers. The duet 3 should be able to handle at least 24 drivers, so expansion isn’t an issue.
  • The duet 3 can be configured to use a raspberry pi (or other similar SBC) to serve the web control, store the gcode files etc and allow the use of plugins with the reprapfirmware. I have been using raspberry pi’s for a number of years with the smart home system so I have a number of them around.
  • As my bed is 500x500x500, I felt that using 3 nema 17’s to move it would be getting towards the top of its limits. I know that its possible to find nema 23’s that would be suitable for use with the duet 2, I didn’t want to restrict myself. The duet 2 can handle up to 2.4 amps per driver and the duet 3 can handle 4 amps.
  • There are individual tool boards planned that would be mounted to the extruder. This reduces the number of wires to each tool from ~12 to 6 (4 for the canbus and 2 for power).
  • The processor has been increased from 120MHz to 300MHz.
  • Any HDMI screen can be connected to the SBC to run the web interface. You are therefore no longer restricted to the paneldue interface.

Now I’m not saying to go out and upgrade a duet 2 to a duet 3 as for standard 3D printers, the cost can’t be justified. But if you are building a tool changer or a larger CNC machine, the duet 3 is a no brainer.

If you do order a duet 3, the following things are supplied:

  • All connectors and crimps to use every connector on the board.
  • A 26 pin cable to connect the duet 3 to an SBC.
  • The crimps required to connect the power cables.
  • An SD card for use in a raspberry pi. (I haven’t used this as my raspberry pi 4 was already setup with an SSD).
  • A sticker for your machine to show that its using a duet 3.

So far, I have the duet 3 setup with a raspberry pi 4Gb. I have updated it and that’s about as far as I’ve got. I have a couple of motors that I’m going to use for the X and Y. I also have the motor that I’m going to use for the tool changer. I have ordered the Z motors (3 off) as well. I’m still on with building my machine so it will be a while before I actually start doing any electronics wiring. Eagle eyed readers will spot that all those motors above equal 6 and there are only 6 drivers on the duet 3 mainboard. I have preordered an expansion board to give me 3 extruders.

More updates on how the build is going to follow.

Yes, I know I’ve been a little bit quiet on here to the point where I haven’t posted in over a month. I’ve been fairly busy with home life (visiting friends on weekends etc) and working away from home in different parts of the country.

I’ve also been working on the design for a new 3D printer. As some of the more regular readers will know, I have/had an Anycubic Linear Plus (ALP) and an Anycubic Predator. Both with a number of upgrades, with the main one being duet 2 control boards. Well the ALP has been sold and I bought a Da Vinci Jr 1.0 for £35 + postage off ebay to tinker with.

The main reason I sold the ALP was to generate funds for a new printer. A coreXY in fact, with built in toolchanger. I was blown away with the possibilities of the E3D toolchanger when I was TCT but the ~£3000 asking price almost made me fall over (I was also impressed by the E3D Hermes and needed an excuse to buy a duet 3). Since then I’ve been researching different toolchanging printers (shout out to the Jubilee printer) to see which design I liked. I knew my next printer was going to be a coreXY and I knew I wanted something a little larger and I couldn’t really find anything I liked.

So Jays Toolchanger CoreXY was born. If anyone comes up with a better name, please let me know in the comments below.

I had a few design goals in mind. Namely I wanted to print roughly 500x500x500, use the duet 3 with toolboards, be fully direct drive and to use as many 3d printed or off the shelf parts as possible (as it stands at the moment, only the locking pin and bed need to be custom machined, although once the locking plate is easily available, I will swap to machined ones).

All files are currently available on Github and Thingiverse and comments on the design are welcome. I have tried to make it as accessible as possible. All of the design work is done in Solidworks.

As it’s all the rage these days, there is also a discord server. Come join me for a chat.

I will add another post with build progress.