¶ Using ATCs with FluidNC
¶ Example
Here is a video of an example. This was originally done in Grbl_ESP32, but the machine was updated to FluidNC.
Warning This is a new feature. The developers can only do limited testing on this because we don't have access to much ATC equipment. You should evaluate any ATC features you want to use with safe, "air jobs" to determine if the features are functional and safe on your machine.
ATCs are a very advanced feature and not recommended by newbies. Most of the developers cannot afford ATC machines to help test and develop this feature. Please become a sponsor of the project if you need help and support. Please be respectful of our time.
¶ Safety
There are a lot of safety issues with ATCs. If your machine opens the ATC while spinning, it is likely to throw that tool across the room with a razor sharp bit. That could kill you. It will also likely do serious damage to your spindle. Be careful and never trust your machine or the firmware. You are the sole person responsible for your safety.
To get the current tool number you can send $G or D#5400
¶ Overview of ATC types supported.
There are 4 types of ATCs that can be supported by FluidNC
¶ No ATC
If you do not use macros or an ATC class, you can still use tool numbers to change spindles. The tool numbers are only used to determine the spindle number. This is the original system since the beginning of FluidNC. See the spindle page.
¶ m6_macro
Each spindle in the config file can have an m6_macro:. This can be gcode or you can specify a file to run with $SD/Run=myfile.gcode. You can use parameters and expressions in the gcode. This gives you access to the tool number, probe values and other information.
pwm:
pwm_hz: 5000
...
atc:
m6_macro: G55 G0X0Y0
¶ ATC Class (C++)
You can create advanced ATC classes. Spindles can use these classes via the atc: config item. This allows any spindle to use any of the existing classes.
atc_manual:
safe_z_mpos_mm: -1.000000
probe_seek_rate_mm_per_min: 800.000000
probe_feed_rate_mm_per_min: 80.000000
change_mpos_mm: 80.000 0.000 -1.000
ets_mpos_mm: 5.000 -9.000 -40.000
ets_rapid_z_mpos_mm: -25.000000
pwm:
pwm_hz: 5000
...
atc: atc_manual
M6_macro:
¶ Special Spindle Classes
If you have an ATC that requires special interaction between the spindle and ATC, you can write a custom spindle class. All information about the tool change goes through the spindle, so you can act upon it at that level if you like.
my_spindle:
pwm: 5000
...
atc:
M6_macro:
my_config_item1:
my_config_item2:
¶ Details
¶ M6 Macro
An m6_macro: can be used with any spindle type. It will run if it is defined and the spindle does not have an ATC config item. Read more about macros here.
You must set the current tool number with M61Q<number> in your macro. This allows you to decide if the tool change was successful. In most cases you will want to set an alarm and exit the macro if there is a problem. Use $Send/Alarm=3 (Abort during cycle)
¶ Gcode behavior
- M61 Q<num> Used to set the tool number already installed. Typically done at startup if the tool number is not right.
- Sets the current tool.
- Macro is not run
- This will change the spindle if Q<tool_num> is in the range of another spindle
- T<anything>
- Preselects the tool. Nothing happens until an M6 comes.
- Macro is not run
- M6
- Runs the macro
- M6 T<current tool> to T<current tool>
- Does nothing
- M6 T<outside current spindle tool range>
- Changes spindle and uses new spindles ATC config.
¶ Typical Job Workflow
coming soon...
¶ spindle/atc: atc_manual
This uses a human to change the tool, but it uses an electronic tool setter to automate the setting of the tool length offset (TLO) so the Z axis only needs to be zeroed on the work once. Ideally the tool setter has some over travel, so you can safely probe faster.
When a tool change is requested for the first time, the length of the currently zeroed tool will be measured. It will then move to a specified tool change location and hold. You manually change the tool and send the resume command. It will measure the new tool and set the TLO to zero the new tool. It will then return the location before the tool change was requested.
¶ Gcode behavior
- M61Q<num>
- Sets the current tool
- If there was a previous tool number it resets the TLO to 0.0
- T0 or M6T0
- Moves to the
change_mpos_mm:position and waits. - Resets TLO and other saved tool info.
- Moves to the
- M6T<not 0> From T0
- Moves to the change location and does nothing else. This is used when you want to insert the first tool.
- M6T<not 0> to T<not 0> first time
- Determines the TS offset
- Goes to tool change location
- Set TLO
- Returns to position before command
- M6T<not 0> to T<not 0> after first time
- Goes to tool change location
- Set TLO
- Returns to position before command
- M6T<current tool> to T<current tool>
- Does nothing
¶ Typical Job Workflow
The atc_manual class is designed to speed up your workflow a little by doing these things when running a CAM file.
- Moving to a convenient to place change tools
- Using a tool setter to eliminate the need to set the Z zero on each tool.
This is what you must do manually before running any CAM files.
- Home the machine
- Install the first tool.
- If the tool was already installed you can send M61Q<tool_num> where <tool_num> is the number of the tool. Like M61Q2
- If you need to install a tool send M6T<tool_num>. The machine will move to the change location. You now install the tool.
- Zero the installed tool on the workpiece.
- Move to a safe Z location.
You can now run your CAM file.
After the gcode file is complete.
- If you have more to do with the current workpiece
- You should be able to run a new gcode file
- If the new file uses a new tool, it will move to the change location for you to install it.
- If you are going to use a new workpiece (even with the same gcode file)
- The previous work zeros are probably no longer valid.
- You must send M6T0 to reset all of the saved values.
- Start the "typical workflow" shown above from the beginning.
¶ Post Processor Notes
Your post processor and resulting gcode is responsible for this.
- Retract from the material before the M6 command
- Turn on the spindle and set the speed after returning from the tool change
¶ Using an automatic touch probe and a toolsetter.
You can use the touch probe as one of your tool numbers. You zero with the touch probe. All cutting tools must use other tool numbers.
- Install the touch probe.
- Send M61Q1 (or whatever tool you have assigned to the probe)
- Use the probe to zero the workpiece.
- Send M6T2 (or whatever is the first tool of your job)
- Install the first tool
- Run your gcode job.
This only works if the touch probe and toolsetter are compatible. If one or both are spring loaded. When the probe touches the toolsetter, the toolsetter must send the signal before the touch probe moves at all.
¶ TODO
Save the TLO and Tool number in NVRAM.
¶ Config File Section
atc_manual:
safe_z_mpos_mm: -1.000000
probe_seek_rate_mm_per_min: 400.000000
probe_feed_rate_mm_per_min: 80.000000
change_mpos_mm: 80.000 0.000 -1.000
ets_mpos_mm: 5.000 -17.000 -40.000
ets_rapid_z_mpos_mm: -25.000000
PWM:
pwm_hz: 5000
...
atc: atc_manual
m6_macro:
- safe_z_mpos_mm:
- This is the z position that the motion will occur. It is generally as high as possible to clear all work with a long bit installed.
- probe_seek_rate_mm_per_min::
- If this is set to a higher value than the
probe_feed_rate_mm_per_min:value it will do this faster probe, retract and then do a second probe at theprobe_feed_rate_mm_per_minrate.
- If this is set to a higher value than the
- probe_feed_rate_mm_per_min:
- This is a probe speed used for determining TLO
- change_mpos_mm:
- This is the location in mpos where you want to change the tools. It should be in an easily accessible location.
- ets_mpos_mm:
- This is the location of the electronic tool setter. The Z location is used to check for empty collets. Lower the spindle down until an empty collet is just above the tool setter. If the spindle ever goes this low on a tool setter probe, it will terminate the tool change with an alarm.
- ets_rapid_z_mpos_mm:
- This can be used to speed up probing. The probe will rapidly move to this Z location before the probe starts.