Next, we will move on to one of the most important assemblies on the Promega, the extruder! This complicated assembly can reach temperatures above 300°C in order to melt plastic and print it.
The extruder assembly contains a fan directly on the front, this is called the Cold-Section Fan. It is meant to keep the extruder block, directly behind it, cold.
Next, there are two smaller fans called Nozzle Fans. These are meant to cool any filament that is pushed out of the nozzle so that it becomes rigid.
On the right of the nozzle fans is a small electronics board called the IR Probe. This probe uses Infra-Red rays in order to detect the bed.
On the left of the extruder is a small deploy-able limit switch, this is also a Z-probe. Z-probes are used in order to measure the exact distance from the nozzle to the bed. They are also used in order to level the bed of the printer as printing requires a very flat and level surface.
You can view the image below to see a diagram of the different extruder components.
Tools are a relatively new concept in 3D printing. They allow you to create different extruder configuration ahead of time that you can quickly switch between while printing.
The Duet Maestro board uses tools in order to allow printing with multiple extruders, or mixing extruders. The Promega actively makes use of this in order to print with:
Compound Mixing: Different tool mixing ratios
Single K'Tana: Dual nozzle prints
You can find your currently configured tools in the Duet Web Console in a table labeled: Tools/Heaters/Extra on the top-left.
In the image above there are two different tools.
In RepRap firmware, tools are defined as
nnn represents a tool number. In the image above there are tools T0 and T1. Each tool has it's own extruder motor attached to it, or multiple if you are mixing.
A tool also has one heater attached to it. All these tools are defined and configured when the printer powers up with G-code commands, we will go over how exactly that works later.
Below are the default tools for the Compound and K'Tana setups. In order to select a tool you can either click on the tool name in the Duet Web Console or you can send the command
nnn represents the tool number.
If you wanted to switch to tool 0, you would send the command:
The Duet Web Console always shows you which tool is selected: it will underline the tool name. In the image above T0 is selected.
T0: Mixing tool
Extruder 0 (Left) & Extruder 1 (Right)
Allows for extruding two filaments and combining them at a 1:1 ratio
T1: Single Left
Extruder 0 (Left)
Extrudes with only the right extruder
T2: Single Right
Extruder 1 (Right)
Extrudes with only the left extruder
T0: K'tana Single Left
Extruder 0 (Left)
T1: K'tana Single Right
Extruder 1 (Right)
In the future, if you find that none of your extruders are working, or an extruder you didn't expect to be running is running, chances are you have the wrong tool selected. Use the
Tnnn command in order to select a tool with number
There are many different filament types used in the 3D printing industry, a Google search will prove that. They vary in material, diameter and many other properties.
The Promega can also print many different materials, but if you are a beginner we recommend ABS-R or PLA. These two materials tend to be easiest to print with.
Printing temperature varies greatly depending on what material you are printing with.
PLA prints well at around 200°C
ABS-R prints well at around 230°C
Follow the section below in order to get started with extruding.
To load filament into the extruder, you will need to find two small holes on the top of the extruder assembly. 1.75mm diameter filament can be loaded into this opening.
It will then be grabbed by the extruder motor and pushed down into the hot-end.
In the Promega's case, that is the nozzle and the aluminum block surrounding it. Once the filament is melted in the hot-end it will come out of the nozzle.
The compound nozzle will have two holes to allow entry to two different filaments. It then melts both filaments and combines them to produce one stream of filament coming out.
The K'Tana has two different nozzles and therefore each filament will get extruded out of separate nozzles.
To load filament, follow the steps below.
Move the extruder to the center of the printer by entering the command:
G1 X200 Y200
Next, heat up the nozzle.
There are multiple ways to heat up the nozzle to your desired temperature. Use the:
G-code Commands (move to here)
Duet Web Console (continue on)
In the table Tools/Heaters/Extra on the Duet Web Console, enter the desired temperature in the circled box below (your Current reading should not have a value of 2000°C, 2000°C is an error value).
Once you have entered the temperature press Enter. You should now see a steady rise in temperature in the Current box and on the graph to the right.
Once the extruder has reached it's set temperature you are ready to load your filament.
Take the filament and insert it into the opening circled in red in the image.
For a Compound Mixing nozzle, you will have to load filament into both openings in the extruder.
For a Single K'Tana nozzle, you will only have to load filament on one opening in the extuder.
Now, on the Duet Web Console go to the Machine Control tab in order to move the extruder motors. In this tab there is a box called Extruder Control.
Here you can select the extruder you want to control and how much filament you want to extrude and at what speed.
If you have the Compound Mixing nozzle, set the Extruder Drive settings to Mix, in order to get both extruder motors to push filament.
If you have the Single K'Tana nozzle , set the Extruder Drive settings to Drive 0 or 1, depending on which side you loaded filament into.
The Feedrate amount should be set to 10mm and the Feedrate to 5mm/sec. You can then press Extrude this should move the filament into the extruder. It could be possible that you have to push the filament properly into the opening until the extruder grabs it.
Once the filament is inside the extruder keep pressing Extrude until filament comes out of the nozzle. You can increase the Feed amount to 50mm or more to decrease the times you have to press Extrude.
You have just created your first print! It probably looks like a long stream of filament, but that counts, right?
You can keep pressing the Extrude button for as long as you like, or you can move on to the next section.
The steps that you accomplished above in order to extrude filament can also be done with G-code commands. Follow the steps below in order to learn more G-code commands.
Select your appropriate tool with
Tnnn. For example, tool 0 with
Turn off the heat to your tool by sending the command
G10 Pnnn S0.
G10 allows you to set a tool temperature. The
P parameter and
nnn represents your tool number that you want to change the temperature of.
Snnn is the temperature of the tool. So by setting the temperature to 0 the tool is turned off.
If you wanted to turn the temperature of a tool back on you would have to enter the command
G10 P0 Snnn where
nnn is your new tool temperature. The
S parameter only sets the active temperature of a tool. This means the tool will only go to that temperature when it is selected or active.
If you wanted to extrude 100mm of filament at a feedrate of 20 mm/sec you could enter the commands below. Remember that you should zero your extruder first before telling your extruder to move. This is because your extruder could have a very high position in mm, for example 10291mm. If you then tell the extruder to move to the absolute position of 100mm. The extruder will have to travel 10191mm backwards, and that will take a long time! You can also turn on relative extruder moves with
M83, and then you would not have to zero the extruder as it just adds 100mm to the position the extruder is already at.
G92 E0G1 E100 F120 ; Remember that Feedrate is in terms of mm/min!G92 E0
M83G1 E100 F120M82
To retract, pull filament back into the extruder, send a negative extruder position. Like
G1 E-100 F3000.
Throughout your printing career with the Promega you will notice other commands to heat up your nozzle.
M105 can also be used to heat up your tools.
M104 Snnn: Heat up your active tool to
M109 Snnn: Heat up your active tool to
nnn°C and wait until temperature is achieved.
M140 Snnn: Heat up your bed to
M190 Snnn: Heat up your bed to
nnn°C and wait until temperature is achieved.
There are even more commands to heat up your extruder. The
G10 command allows you to heat up any tool including when you don't have the tool selected. This command can be useful when you are attempting to change the temperature of tools while they are not selected. The command
G10 allows you to change the temperature or offset of a specific tool.
G10 Pnnn Xnnn Ynnn Znnn Rnnn Snnn :
Pnnn : Represents the tool number of the tool you are attempting to change the temperature or offset of.
Znnn : Represent the X, Y and Z offset of the tool
Rnnn : The tool's standby temperature. Or the temperature of the tool when it is not selected, but was previously active.
Snnn : The tool's active temperature. Or the temperature of the tool when it is selected.
G10 P1 X10 Y0 Z0 R120 S230 , This will set the offset of tool 1 to 10mm in the positive X direction. It will also set the active temperature of the tool to 230C and the standby temperature of the tool to 120C.
G10 command is especially useful for mixing and switching prints.