Anycubic Kossel Linear Plus to Duet3D – Part 7: Initial Configuration

I found the Anycubic repository on github, and looked at configuration.h to find a few starting values for the configuration.  I put these values, and a bunch of “reasonable guesses” into the RepRap Firmware online configuration tool, and downloaded this zip file

Since I did all that, you don’t have to…  the above is so that you know how it happened if you ever want to re-do an initial configuration for a slightly different printer.  Instead, just download the zip file (last link above).

You can look inside it if you wish… but the real goal is to upload it to the Duet board.

In the “Getting Connected” guide in the prior step, you learned how to open the “Duet Web Control” (DWC) to your printer.  Open that now.

Navigate to SETTINGS, the GENERAL tab, and click the a large blue button “Upload File(s)”.   Upload the entire zip file.  (Do not unzip it).

The Duet will offer to reboot.  Click OK.


Anycubic Kossel Linear Plus to Duet3D – Part 4: First Power Up

1) Power on

After checking all wires AGAIN, and with the bed set aside where you can see the Duet board, attach the power cord and press the power on switch.  KEEP your finger on the switch and if you see, hear, or smell ANYTHING you don’t like, turn it off immediately.

2) Verify Lights

You should see the red and blue power/status lights on the edge of the board (top edge in the picture below) come on and change for a few seconds as the board boots.

You should see at least three of the four endstop lights come on (the fourth depends on your z-probe, more about that below). These are red lights between the motor connectors (lower right edge in the photo below)

3) Test Switches

Use your fingers to press each endstop switch at the top of the tower.  One of the lights on the board, near the motor connectors, should go off and on as you click the switch.  It should stay on when you release the switch.

Use your finger to press the Z-Probe switch.  The fourth light should change.  It may be on or off when you’ve released the switch (more about that later).

4) Celebrate!

Seriously.  Power off, take a pause, say “WooooHooo” loudly enough that your family looks at you funny, have a beer, whatever works for you.

Click Here for Part 5

Anycubic Kossel Linear Plus to Duet3D – Part 3: Wiring

Wiring and switching the boards:

1) Remove the old TriGorilla board

Hint: Label the motors X, Y, and Z, per the way they were plugged in originally by the factory.

Power off, remove the power cord, lift the bed, and unplug everything from the existing tri-gorilla controller board. Remove the TriGorilla (main controller) board.

Remove the LCD from the front of the printer. It will not be re-used.

2) Mount the Duet board.

There are numerous mounts on Thingiverse that could be adapted. I chose this one and then modified it by cutting a square out of the base, both to eliminate the “logo” and to speed up printing. Note this does NOT “present” the SD mount and USB “through the rail”. The need to reach these on a Duet is so rare that I am fine with having to lift the bed to access them.

3) Wiring motors, re-using connectors. 

First, plug in the motors using existing cables. If you look, the holes for the pins are much nearer one side of the plug than the other. Orient the narrow side toward the “tab” on the Duet board. X, Y, Z and E0 are all labeled on the Duet board. Leave factory jumpers in place on the Duet dual Z connector.

4) Wiring endstops, connectors MUST change 

The supplied AKL endstop cables have two-pin connectors. The Duet board REQUIRES the two pins from a microswitch be the “outer” two pins of a three pin connector. Therefore the connectors must be changed.

The “Duet” way to do this is to cut the two pin connectors off, crimp on new “fingers”, and insert these into the outer two pins of a three pin shell. The pins and shells are all provided. These are NOT polarized.

I happened to have a bunch of “Radio control style” 3 pin shells, which are compatible with the “pins” that are in the AKL provided shells. Therefore, I pulled the pins out of the two-pin shells (by lifting the plastic tab with the tip of a scalpel or x-acto) and re-inserted those pins in the outer two slots of a 3 pin shell.

This photo shows one of the AKL provided two-pin shells still on the end of a cable, the Duet provided 3-pin shells and pins, and the “Radio Control” style 3-pin shells that I happened to have.

You will change FOUR cables. The three that come from the X, Y, and Z towers, as well as the one that is in the bundle coming from the effector. That is the “Z-Probe” wire.

These are NOT polarized. Although, if you are OCD, you may wish to be consistent.

After you’ve changed the connector, plug the enstops in as shown in the photo. Remember the hint to label your motors? You can follow the endstop wire from a tower and motor label to know where to plug it.

Plug the cable that is in the bundle from the effector, the “Z-Probe” wire, plug that into the E0 endstop. The photo only shows three of the four. These are NOT polarized.

4) Wiring fans, connectors may or may not change 

The AKL fan connectors will physically fit, sort of. Best practice is to cut them off, and wire two-pin connectors as provided by Duet. These ARE polarized, look at the photos or a wiring diagram of the Duet.

If you do re-use the AKL connectors, the way they must go for correct polarization requires a bit of force-fit and risks breaking the “tab” on the Duet board. I chose to be lazy, re-use the AKL connectors, and I did indeed break one of the tabs. You can see it in the second photo.

Fan 0 on AKL goes to Fan 0 on Duet.

Fan 2 on AKL goes to Fan 1 on Duet.

4) Other wiring from the Effector

The thermistor wire (skinny white pair) is not polarized and plugs into thermistor 0 on the Duet. See photo.

The heater wires for the effector hot-end come from Anycubic as bare wire that has been soldered into one bundle. CUT THIS OFF. Ideally, attach crimp-on connectors… if not, just twist the bare wires. Put these in the screw terminals for Heater 0.

Neatly bundle the excess effector wiring and secure it with a small wire-tie. It is also good practice to secure the spiral wrapped bundle to the frame, in order to prevent long-term problems from repeated flexing.

Check all wiring carefully against these photos… we are getting close!

5) Wires from power supply, connectors should change 

The AKL power supply wiring has three things that will need to change: It is very likely not long enough to reach the power connector on the Duet, it comes from the factory with soldered ends, and it has two positives (red) and two negatives (black) where Duet needs only one of each. (And you can’t leave the other set just floating around).


Remove the power supply completely from its mount, remove the end-casing, remove the four existing low voltage wires (two black, two red).

Make new, longer wires, one black, one red. Ideally, use crimp on connectors, “spade” on the power supply end, and “bootlace” on the Duet end. If this is not possible, use bare twisted wire. DO NOT solder.

Since I’d already changed the existing wires to bootlace crimps, I re-used the existing wires by cutting them up and solder/heat shrink the pieces to make them longer.

Connect these to the big green screw connectors labeled “VIN”. These ARE polarized and are one of the MOST IMPORTANT polarization connections to get right. Check it carefully.

Photos below.

6) Wiring from bed, connectors should change 

Cut the soldered ends off the bed heater wires. Crimp on bootlace, or just twist the bare ends. These go in the other big green connector, marked for the bed heater, and are not polarized.

The bed thermistor (two thin white wires) go to the connector right next to the big green screw terminals where the bed heater connected.

4) That’s it!!

Check everything one more time, then power up and get ready to configure.


Click here for Part 4

Anycubic Kossel Linear Plus to Duet3D – Part 2: Stock “Gotchas”

The documentation for physical assembly and wiring is EXCELLENT.  Large illustrations of steps; hardware in bags. Assembly is straightforward and only took a few hours, maybe three or four, to first power up. There were a few things to note:

The first two “Gotchas” are with regard to the power supply wiring.  Anycubic sends it pre-soldered.  There are two problems with this.

1) Soldered power wires.
Soldered wires in a screw terminal results in the solder deforming over time and the connection loosening.  This leads to heat.  A vicious circle forms and there is at least some fire danger.   Bad, bad, thing in what is otherwise a very nice kit. Also, the soldered ends on the wires from the power supply are much too large to insert in the screw terminals.

2) Blocked access to power connector screw.
The pre-mounted main board is in a position that causes it to completly block one of the screw terminals for incoming power. Not that big a deal… loosen the board, connect the wire, re-mount the board, right? At the same time, this ENSURES that this particular screw will never be tightened after original build; couple that with solder/screw that works loose, and gotcha (1) and (2) synergize to be even more dangerous.

I ended up cutting the soldered ends off the power supply wires, and all the heater wires, and crimping on “Bootlace” terminals.  Some builders, maybe even most, will not have the crimp tool and terminals…

The third “Gotcha” is much more frustrating (and less dangerous).

3) Z-Probe doesn’t work.
The Z-Probe is “backwards” to the firmware with regard to “Normally Open” (NO) vs. “Normally Closed” (NC). The first runs of “Automatic Leveling / Set Z height” resulted in a Home, a bunch of wiggles, and a reboot. Sigh…

It is possible to correct this by inverting Z+ pin in firmware, or by changing the microswitch in the probe. I chose to change the physical probe. Mainly because it was shipped as NO and that is the same as a probe not plugged in at all… I specifically desired NC so that a broken wire or loose connection would behave as though the probe was already triggered. Keeping in mind the long range goal is to install a Duet controller, I wanted the probe to be NC for the Duet as well. The Duet will work with a probe either way; again, I want broken/missing to be detected, BEFORE a nozzle crash.

If you choose to modify the probe, open it up, then cut the trace going to the “furthest” pin on the switch, and solder a wire to the center pin instead. Use a SMALL wire; it has to fit in a channel in the aluminum chassis of the probe.

This is frustrating because the instructions are very clear about how to auto-Z-calibrate and auto-level. This is one of the most important features to make a Delta acceptable to people who’ve never had a Delta before. The failure mode, just wiggle at the top, is NOT illuminating to the actual problem… Sigh…


Click here for Part 3

Anycubic Kossel Linear Plus to Duet3D – Part 1

There have been a lot of posts on the Duet3D forums about converting “Anycubic Kossel Linear Plus” printers by installing a Duet controller.  The price of an AKL+, shipped, falling near $200 US probably has a lot to do with this.

I have an AKL not Plus, and it has been an excellent little printer.  I also happen to have a Duet WiFi available at the moment. Therefore, I decided to get an AKL+, and convert it to Duet control.

Step 1 of that conversion: Be sure it works stock out of the box.  Ordered on June 24 2018 via the Anycubic store on AliExpress, delivered on Jun 28th.  $221, shipped.  Four days to Texas.  Not bad!

The degree of pre-assembly has gone WAY up since I bought my non-plus in Sept of 2017.

Open box and find everything nicely packaged.  Even a full Kilo of Filament under the cables.

Main board is installed, heater is on alu plate, horizontal extrusions are assembled into corners forming triangles, motors and idler pulleys are installed, effector is completely assembled with hot end installed and wired, diagonal arms are installed to effector and carriages, and more.

This will be a snap to assemble.  Hardly need the manual… but I’ll check it carefully to see if there are any “gotchas” for beginners.

And… hardware is now packaged in separate bags by step.  Very nice.


Also, the linear slides “feel” nicer than the ones on my prior Anycubic Kossel.   Maybe luck of the draw; maybe an improved part.


Click here for Part 2

Some upgrades to the BFD

The BFD (Big Fast Delta) got moved across the room, for reasons unrelated to the printer itself.  On the way, I broke the one diagonal brace it had installed.  It was always planned to have three… but I installed one, started printing things, and never went back.

Many large Deltas have diagonal braces made of aluminum.  I didn’t like the look of that, so I elected to brace with non-stretch fishing line.  There are many choices, I used “Berkely SpiredWire Stealth-Braid” 60 lb test. Primarily because it was on a peg at a local WalMart.

I designed “Winders” to provide even tension.

This seems to work.  Wiggling the frame with no braces results in a lot of movement up top.  Wiggling the frame with the lines installed results in lifting the lower corners.