Base: Marlin 1.1.0-RC6 - 4 July 2016 (c450851)
Not for production use – use with caution!
This is a Development Branch of Marlin. It is built on a High Resolution Mesh Bed Leveling System that was originally pioneered by Epatel. It also incorporates the earlier concepts of 3-Point Bed Leveling and Grid Based Bed Leveling. The System provides backward compatabily with the 3-Point and Grid Based Leveling by giving the user the ability to create a zero'ed mesh and then tilting it in the prescribed manner. These two backward compatable modes of operation can be done with a G29 P0 T or a G29 P0 G 3 (for a 3 x 3 grid) respectively.
Currently, the Unified Bed Leveling System requires the user to have an LCD Panel and a Z-Probe. Later, when things stabilize, these constraints can be relaxed. But a small amount of code clean up is necessary before this can happen.
In order to realize the full benefits of the system, the user will need to choose a Mesh size and then populate it with accurate values. The bulk of the values can be obtained automatically with a G29 P1 M command. The unreachable (by the probe) areas can be populated by either performing Manual Probing with G29 P2 command or a G29 P3 command which fills an area of the Mesh with a specified value. It is then anticipated that the user should utilize the new G26 Mesh Validation Command to see how well they have the Mesh defined for thier print bed. With this information the user would likely move on to the Fine Tuning the Mesh with a set of G29 P4 commands. The bulk of the UBL System was developed using a 10 x 10 Mesh. The system can go up to 15 x 15 if needed.
When bringing up the system, it is advisable to start with the Configuration.h file associated with the release and make as few changes as possible. (Look in the Examples folder for a folder named Roxy-3D. Those are well tested .h files I used throughout development.) The System was developed on a Prusa i3 machine with a 20x4 LCD display. The closer you are to the development system, the less likely you are to have issues. Once you have the System up and running correctly it should be OK to start making a few changes at a time to get the Configuration.h file more closely aligned with your preferred configuration. There is a lot of new code in this package and by moving to your preferred configuration in steps it will help us give you good support.
The full set of parameters for G29 and G26 are provided at the end of this page.
- Inital Release
The UBL System is currently fully functional on Prusa i3 type machines with a 20x4 LCD Panel. It is expected to be fully functional on all machine types with or without an LCD Panel prior to it being released as a 'Stable Release'.
- Relax requirement for LCD Panel.
- Relax requirement for a Z-Probe.
- Clean up the formatting of the Parameter Options at the bottom of this page.
- Deltas have not been checked out and verified for correct operation yet. It should be noted that this code was originally designed and written to address the horrible quality issues I have with my Geeetech Delta printer. That was my original intent but I got side tracked and ended up with the Cartesian versions running first. I will get the Delta version going as soon as I get some spare time. (I have to fix my Delta and put it back together again. So it may take some time.) The code was written to be compatible with Delta's and should not be very difficult to get running correctly. If somebody with a Delta wants to give it a try, PLEASE DO! And then report back any areas where things are not working correctly.
- Speed up the mesh_buffer_line() function. A large inital move will stutter because this function calls itself recursively and starts at the end of the line. There are a couple of solutions, and really we are only doing this to make the motion a little less surprising. No harm comes from what it does right now. (Once moves get queued up, you never see the stutter.) On solution would be to break the inital movement into two (or three) smaller movements. Or we could recurse and get the first pieces of the line first.
- LCD Panel Menu items should be added to facilitate the generation, loading, storing, tilting and editing of a Mesh. Right now, these are all done using PronterFace. The control should be expanded to allow operation purely from the LCD Panel.
- The UBL System was designed and coded with the expectation that some machines without LCD Panels will be using the system. Right now, the LCD’s Encoder Wheel is used in a number of places to do fine adjustments. That requirement can be relaxed and those adjustments should also be possible to be made through PronterFace or Repitier Host. That (small amount of) extra code is not yet in place.
- Work with PronterFace and Repetier Host to allow Marlin to use non-proportional fonts. The problem is when printing out Mesh Maps the use of spaces and minus signs really messes with the appearance of the Mesh. So, Marlin has to compensate and print extra spaces and dashes in an attempt to even out and align the columns. Everything is tuned for PronterFace, so Mesh Generation (and editing) is best done with it. But feel free to use what ever you are comforatable using.
Please test this firmware and inform us if it misbehaves in any way. Volunteers are standing by!
The current Marlin UBL team consists of:
| Name | Github | Language(s) |
|---|---|---|
| Scott Lahteine | @thinkyhead | English |
| João Brázio | @jbrazio | English, Portuguese |
| Roxanne Neufeld | @Roxy-3D | English |
Marlin is published under the GPL license because we believe in open development. The GPL comes with both rights and obligations. Whether you use Marlin firmware as the driver for your open or closed-source product, you must keep Marlin open, and you must provide your compatible Marlin source code to end users upon request. The most straightforward way to comply with the Marlin license is to make a fork of Marlin on Github, perform your modifications, and direct users to your modified fork.
G29: Mesh Based Compensation System
Parameters understood by this leveling system:
A Activate Activate the Unified Bed Leveling system.
B # Business Use the 'Business Card' mode of the Manual Probe subsystem. This is invoked as
G29 P2 B The mode of G29 P2 allows you to use a bussiness card or recipe card
as a shim that the nozzle will pinch as it is lowered. The idea is that you
can easily feel the nozzle getting to the same height by the amount of resistance
the business card exhibits to movement. You should try to achieve the same amount
of resistance on each probed point to facilitate accurate and repeatable measurements.
You should be very careful not to drive the nozzle into the bussiness card with a
lot of force as it is very possible to cause damage to your printer if your are
careless. If you use the B option with G29 P2 B you can leave the number parameter off
on its first use to enable measurement of the business card thickness. Subsequent usage
of the B parameter can have the number previously measured supplied to the command.
Incidently, you are much better off using something like a Spark Gap feeler gauge than
something that compresses like a Business Card.
C Continue Continue, Card or Current Location. This is not a primary command. C is used to
further refine the behaviour of several other commands. Issuing a G29 P1 C will
continue the generation of a partially constructed Mesh without invalidating what has
been done. Issuing a G29 P2 C will tell the Manual Probe subsystem to use the current
location in its search for the closest unmeasured Mesh Point. When used with a G29 Z C
it indicates to use the current location instead of defaulting to the center of the print bed.
D Disable Disable the Unified Bed Leveling system.
F # Fade Fade the amount of Mesh Based Compensation over a specified height. At the specified height,
no correction is applied and natural printer kenimatics take over. If no number is specified
for the command, 10mm is assummed to be reasonable.
G # Grid Perform a Grid Based Leveling of the current Mesh using a grid with n points on
a side.
H # Height Specify the Height to raise the nozzle after each manual probe of the bed. The
default is 5mm.
I # Invalidate Invalidate specified number of Mesh Points. The nozzle location is used unless
the X and Y parameter are used. If no number is specified, only the closest Mesh
point to the location is invalidated. The M parameter is available as well to produce
a map after the operation. This command is useful to invalidate a portion of the
Mesh so it can be adjusted using other tools in the Unified Bed Leveling System. When
attempting to invalidate an isolated bad point in the mesh, the M option will indicate
where the nozzle is positioned in the Mesh with (#). You can move the nozzle around on
the bed and use this feature to select the center of the area (or cell) you want to
invalidate.
K # Kompare Kompare current Mesh with stored Mesh # replacing current Mesh with the result. This
command litterly performs a difference between two Mesh.
L Load Load Mesh from the previously activated location in the EEPROM.
L # Load Load Mesh from the specified location in the EEPROM. Set this location as activated
for subsequent Load and Store operations.
M Map Display the Mesh Map Topology. The parameter can be specified alone (ie. G29 M) or
in combination with many of the other commands. The Mesh Map option works with
all of the Phase commands (ie. G29 P4 R 5 X 50 Y100 C -.1 M)
The P or Phase commands are used for the bulk of the work to setup a Mesh. In general, your Mesh will start off being initialized with a G29 P0 or a G29 P1. Further refinement of the Mesh happens with each additional Phase that processes it.
P0 Phase 0 Zero Mesh Data and turn off the Mesh Compensation System. This reverts the
Delta Printer to the same state it was in before the Delta Mesh Based Compensation
System was turned on. Setting the entire Mesh to Zero is a special case that allows
a subsequent G or T leveling operation for backward compatability.
P1 Phase 1 Invalidate entire Mesh and continue with automatic generation of the Mesh data using
the Z-Probe. Depending upon the values of DELTA_PROBEABLE_RADIUS and
DELTA_PRINTABLE_RADIUS some area of the bed will not have Mesh Data automatically
generated. This will be handled in Phase 2. If the Phase 1 command is given the
C (Continue) parameter it does not invalidate the Mesh prior to automatically
probing needed locations. This allows you to invalidate portions of the Mesh but still
use the automatic probing capabilities of the Unified Bed Leveling System. An X and Y
parameter can be given to prioritize where the command should be trying to measure points.
If the X and Y parameters are not specified the current probe position is used. Phase 1
allows you to specify the M (Map) parameter so you can watch the generation of the Mesh.
Phase 1 also watches for the LCD Panel's Encoder Switch being held in a depressed state.
It will suspend generation of the Mesh if it sees the user request that. (This check is
only done between probe points. You will need to press and hold the switch until the
Phase 1 command can detect it.)
P2 Phase 2 Probe areas of the Mesh that can not be automatically handled. Phase 2 respects an H
parameter to control the height between Mesh points. The default height for movement
between Mesh points is 5mm. A smaller number can be used to make this part of the
calibration less time consuming. You will be running the nozzle down until it just barely
touches the glass. You should have the nozzle clean with no plastic obstructing your view.
Use caution and move slowly. It is possible to damage your printer if you are careless.
Note that this command will use the configuration #define SIZE_OF_LITTLE_RAISE if the
nozzle is moving a distance of less than BIG_RAISE_NOT_NEEDED.
The H parameter can be set negative if your Mesh dips in a large area. You can press
and hold the LCD Panel's encoder wheel to terminate the current Phase 2 command. You
can then re-issue the G29 P 2 command with an H parameter that is more suitable for the
area you are manually probing. Note that the command tries to start you in a corner
of the bed where movement will be predictable. You can force the location to be used in
the distance calculations by using the X and Y parameters. You may find it is helpful to
print out a Mesh Map (G29 M ) to understand where the mesh is invalidated and where
the nozzle will need to move in order to complete the command. The C parameter is
available on the Phase 2 command also and indicates the search for points to measure should
be done based on the current location of the nozzle.
A B parameter is also available for this command and described up above. It places the
manual probe subsystem into Business Card mode where the thickness of a business care is
measured and then used to accurately set the nozzle height in all manual probing for the
duration of the command. (S for Shim mode would be a better parameter name, but S is needed
for Save or Store of the Mesh to EEPROM) A Business card can be used, but you will have
better results if you use a flexible Shim that does not compress very much. That makes it
easier for you to get the nozzle to press with similar amounts of force against the shim so you
can get accurate measurements. As you are starting to touch the nozzle against the shim try
to get it to grasp the shim with the same force as when you measured the thickness of the
shim at the start of the command.
Phase 2 allows the M (Map) parameter to be specified. This allows the user to watch the progression
of the Mesh being built.
P3 Phase 3 Fill the unpopulated regions of the Mesh with a fixed value. The C parameter is used to
specify the Constant value to fill all invalid areas of the Mesh. If no C parameter is
specified, a value of 0.0 is assumed. The R parameter can be given to specify the number
of points to set. If the R parameter is specified the current nozzle position is used to
find the closest points to alter unless the X and Y parameter are used to specify the fill
location.
P4 Phase 4 Fine tune the Mesh. The Unified Bed Leveling System assume the existance of
an LCD Panel. It well be possible to fine tune the mesh without the use of an LCD Panel
soon. (More work and details on doing this later!)
The System will search for the closest Mesh Point to the nozzle. It will move the
nozzle to this location. The user can use the LCD Panel to carefully adjust the nozzle
so it is just barely touching the bed. When the user clicks the control, the System
will lock in that height for that point in the Mesh Compensation System.
Phase 4 has several additional parameters that the user may find helpful. Phase 4
can be started at a specific location by specifying an X and Y parameter. Phase 4
can be requested to continue the adjustment of Mesh Points by using the R(epeat)
parameter. If the Repetition count is not specified, it is assumed the user wishes
to adjust the entire matrix. The nozzle is moved to the Mesh Point being edited.
The command can be terminated early (or after the area of interest has been edited) by
pressing and holding the encoder wheel until the system recognizes the exit request.
Phase 4's general form is G29 P4 [R # of points] [X position] [Y position]
Phase 4 is intended to be used with the G26 Mesh Validation Command. Using the
information left on the printer's bed from the G26 command it is very straight forward
and easy to fine tune the Mesh. One concept that is important to remember and that
will make using the Phase 4 command easier to use is this: You are editing the height of
the nozzle at these locations. If you have too little clearance and not much plastic
was extruded in an area, you want to RAISE the nozzle at this location. If you did not
get good adheasion, you want to LOWER the nozzle at that location.
Once you get comfortable with the command, you don't even need to look at the LCD Panel.
As the System runs the nozzle around the bed, you can just click the Encoder Wheel if you
like the situation at that location. If you just want a minor change, a few clicks of the
Encoder Wheel in the right direction are fast and easy to do.
P5 Phase 5 Adjust Mesh to mean height. The Mesh is analyzed and the mean height of it is
calculated. The Standard deviation of the points within the mesh are also
calculated. With this information, the mesh is adjusted to have a mean of 0.0.
Probably, this operation should not be performed on a Mesh if more additions are
going to be made to it. One of the primary reasons for doing this is to make the
Mesh Map easier to analyze and understand. But it is also useful for the case where
your G28 homes the Z Axis at a place where the value is significantly different from
the bed's mean value. (ie. Most of your bed is more or less than your G28 value.)
Q # Test Load specified Test Pattern to assist in checking correct operation of system. This
command is not anticipated to be of much value to the typical user. It is intended
for developers to help them verify correct operation of the Unified Bed Leveling System.
S Store Store the current Mesh in the Activated area of the EEPROM.
S # Store Store the current Mesh at the specified location in EEPROM. Activate this location
for subsequent Load and Store operations.
T 3-Point Perform a 3 Point Bed Leveling on the current Mesh
W What? Display valuable data the Unified Bed Leveling System knows.
X # Specify X Location for this line of commands
Y # Specify Y Location for this line of commands
Z Zero Probes to set the Z Height of the nozzle. The entire Mesh can be raised or lowered
by just doing a G29 Z
Z # Zero The entire Mesh can be raised or lowered to conform with the specified difference.
Z_PROBE_OFFSET_FROM_EXTRUDER is added to the calculation.
G26: Mesh Validation Tool
G26 Is a Mesh Validation Tool intended to provide support for the Marlin Unified Bed Leveling System.
In order to fully utilize and benefit from the Marlin Unified Bed Leveling System an accurate Mesh must
be defined. G29 is designed to allow the user to quickly validate the correctness of her Mesh. It will
first heat the bed and nozzle. It will then print lines and circles along the Mesh Cell boundaries and
the intersections of those lines (respectively).
This action allows the user to immediately see where the Mesh is properly defined and where it needs to
be edited. The command will generate the Mesh lines closest to the nozzle's starting position. Alternatively
the user can specify the X and Y position of interest with command parameters. This allows the user to
focus on a particular area of the Mesh where attention is needed.
B # Bed Set the Bed Temperature. If not specified, a default of 60 C. will be assumed.
C Current When searching for Mesh Intersection points to draw, use the current nozzle location
as the base for any distance comparison.
D Disable Disable the Unified Bed Leveling System. In the normal case the user is invoking this
command to see how well a Mesh as been adjusted to match a print surface. In order to do
this the Unified Bed Leveling System is turned on by the G26 command. The D parameter
alters the command's normal behaviour and disables the Unified Bed Leveling System even if
it is on.
H # Hotend Set the Nozzle Temperature. If not specified, a default of 205 C. will be assumed.
F # Filament Used to specify the diameter of the filament being used. If not specified
1.75mm filament is assumed. If you are not getting acceptable results by using the
'correct' numbers, you can scale this number up or down a little bit to change the amount
of filament that is being extruded during the printing of the various lines on the bed.
K Keep-On Keep the heaters turned on at the end of the command.
L # Layer Layer height. (Height of nozzle above bed) If not specified .20mm will be used.
M # Multiplier Retraction Multiplier. Normally not needed. Retraction defaults to 1.0mm and
un-retraction is at 1.2mm These numbers will be scaled by the specified amount
N # Nozzle Used to control the size of nozzle diameter. If not specified, a .4mm nozzle is assumed.
O # Ooooze How much your nozzle will Ooooze filament while getting in position to print. This
is over kill, but using this parameter will let you get the very first 'cicle' perfect
so you have a trophy to peel off of the bed and hang up to show how perfectly you have your
Mesh calibrated.
P # Prime Prime the nozzle with specified length of filament. If this parameter is not
given, no prime action will take place. If the parameter specifies an amount, that much
will be purged before continuing. If no amount is specified the command will start
purging filament until the user provides an LCD Click and then it will continue with
printing the Mesh. You can carefully remove the spent filament with a needle nose
pliers while holding the LCD Click wheel in a depressed state.
R # Random Randomize the order that the circles are drawn on the bed. The search for the closest
undrawn cicle is still done. But the distance to the location for each circle has a
random number of the size specified added to it. Specifying R50 will give an interesting
deviation from the normal behaviour on a 10 x 10 Mesh.
X # X coordinate Specify the starting location of the drawing activity.
Y # Y coordinate Specify the starting location of the drawing activity.