Here, we have another board from Flymaker and Mellow, this time designed as a drop in replacement for the stock Ender 3 board. It has been designed with input from GloomyAndy and myself.

So why would this be a good candidate for replacing your Ender 3 board? Well there are a number of Pro’s

  • Its based on the very powerful STM32F407VGT6. To put this into perspective, it is the same processor that is used in the SKR Pro and GTR boards. It is faster and more powerful that the processor found in the Duet 2 WiFi boards.
  • It is the same size as the current Ender 3 board, with the same layout to make swapping over a breeze.
  • It is equipped with an ESP07s on-board which also has an external antenna, meaning minimal to adjustment is required to install this in the stock metal housing.
  • It has 2 controlable fan ports allowing both the hotend and part cooling fans to be controlled. No more whirring fans when you are not printing.
  • It has an on-board MAX31865 and MAX6675. What does this mean in real terms? It has native support for both a PT100 and ‘K’ type thermocouple. Even the Duet boards can’t do that without purchasing a separate add-on board.
  • It has a port to use the stock screen. At the moment, the software doesn’t support this but it is being worked on. There is also a separate serial connection to plug in a TFT, Paneldue or one of Flymakers own screens.
  • And of course, there us a dedicated BLTouch connector.

This board is hands down the most capable board on the market for the Ender 3. Did I also mention that it is Fully supported by the STM32 port of RepRapFirmware?

It can be purchased now from the Mellow Store on aliexpress. There are also full instructions for getting this board up and running with RepRapFirmware available here. As always, if you have any issues please join us on Discord and we will be happy to support you further.

This is the first board available that has been explicitly designed to use the LPC port of RepRapFirmware.

As can be seen in the image above, this board has an on-board ESP8266 wifi module, removing the need to install an adapter board. Below is a quick overview of some of the features available.

  • 6 x driver slots
  • 3 x controllable fan outputs
  • 3 x extruder connections (outputs and thermistors)
  • 6 x endstop inputs
  • 1 x bltouch header
  • USB-C rather than micro USB.

This is definitely a good mid-range board that would cover most single or dual extruder printers.

It can be purchased from the Mellow Store on aliexpress. Information about setting this board up with RepRapFirmware can be found here. As always, if any support is needed, just us on Discord and we’ll be happy to help.

I recently managed to get my hands on some Fly TMC2209 drivers. I can hear you asking though, why am I writing about them, there must be something special right?

I’m not going to go into specifications etc because everyone who comes here will know what a TMC2209 is and what its capable of.

What I really want to point out about these drivers is that, unlike other manufacturers 2209 drivers, when not using sensorless homing, there is no need to remove the diag pin when the motherboard being used has no means to do so. On the underside of the driver, there is a small switch used to enable the diag pin. Other than that bombshell, they are well designed and well made. Definitely recommended.

They can be purchased from the Mellow Store on aliexpress

I know I’ve been slightly quiet on here recently. You would’ve thought with all this lockdown going on that I’d have more time to get all my projects sorted but unfortunately that isn’t the case.

I just wanted to bring to people’s attention that it’s now possible to run an SKR v1.4 (or SKR v1.3 for that matter) with RepRapFirmware and an SBC attached. This setup emulates the newer duet 3 setup (minus the expandability of expansion and toolboards).

What do you get from running this setup? Well, firstly you get a faster connection to the DWC (RepRapFirmware web interface). Although the SKR with an ESP8266 attached is more than functional, if you’re uploading a large gcode file it can take a while. You also get the ability to connect to the setup using ethernet rather than wifi. Finally, as the platform matures, there will be the ability to use plugins.

As with adding an ESP8266 to the SKR v1.4, some resistors etc are required. All the information can be found on the LPC-RRF wiki.

I was asked to produce updated config files for the Anycubic Predator which has been upgraded to a duet 2 board running the latest RC of RRF3.

I have uploaded my files to github and they can be found here. This is for a setup where a smart effector has been fitted. There won’t be too much to change for a stock predator if you wanted to get it to work.

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

As part of my CoreXY Toolchanging build, I need a number of extruders. I wanted to explore the different options available. As great as the E3D Hemera looks, I can’t justify the £108 cost per extruder (and for my CoreXY I need 6) when I wouldn’t need all the added benefits for every extruder.

I had a look around on my favourite source of parts (Aliexpress) and found the Mellow BMG Extruder. I’ve had my eye on Mellow branded items for a while now as they seem to be up and coming in the cheap knockoff world. They have even cloned the Mosquito Hot End, which so far seems to be reviewing well and at some point I may well order one.

I ordered the Set 2, which comes with the extruder and the motor. Everything came nicely wrapped in a polystyrene box. The main body is injection moulded, as is the larger driving gear. The machining of the teeth on the gears look good and I am generally happy. The purple piece in the photo below held the gear which fits to the extruder in place which I thought was a nice little touch, and is not needed for every day use. The plastic gear has also been mounted centrally on the shaft so rotates correctly when installed. It looks as though Mellow have decent quality control.

In the kit you get all of the tools required to fit the extruder as well as the fitting to allow it to be used in bowden mode. I will be using this extruder in direct mode. There are also two lengths of screws to be used to fit it either directly to the motor or with a mount in between.

I only had one issue with the extruder in that the way I mount it on my machine. The BMG clone when assembled is slightly thicker due to the name badge and the “waves” that have been moulded into the plastic in the front. So I had to spend a little time sanding the front down to get it to fit in my custom mount.

I have yet to print with it (still assembling the printer) but at the moment, the Mellow BMG clone definitely looks like a very good purchase.

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.