Updating the Axis Configuration File
Many values and activities used in this system are based on the respective axis’ configuration. Those configurations are in the respective axis file found in the directory:
| /cnc/linuxcnc/configs/REB/REB_Axes |
The settings you should consider changing are:
- SCALE, and
- STEP_SCALE
The calculations and notes for each setting used is in the comments fields in the file for the respective axis.
Notes:
- It is recommended that you make a copy the current line, and comment it out (add a “#” as the first character in the line). For example:
| # SCALE = 17.778 | ← The old value, commented out |
| SCALE = 25 | ← The new value |
Virtual desktop pager
- Debian Linux has a virtual desktop pager which allows for task switching easily. This is the set of 4 blocks shown at the top of the screen towards the right. Each of these blocks is a workspace (or virtual desktop). The selected desktop has a dark grey background; the unselected three are lighter grey.
- When making changes, the recommended editor is Geany.
Setting the Scale
Stepper Motor Settings
The stepper motors typically used have these settings:
| 1 step | = | 1.8° | |||
| ① | 1 motor rev | = | 360° | = | 200 steps |
| 1.8° |
Driver Settings
The DM542T Digital Stepper Driver is usually set to
| ② | 1 step | = | 32 microsteps |
Which means, based on ① and ②, that the item driven by this stepper motor moves at the rate of:
| ③ | 200 | steps | X | 32 | microsteps | = | 6,400 | microsteps |
| motor rev | step | motor rev |
Leadscrew Settings
The leadscrew used in this example has these parameters:
| Pitch | = | 2 mm |
| Starts | = | 4 |
Therefore,
| ④ | Linear Movement | = | 2 | mm linear movement | X | 4 starts | = | 8 | mm linear movement |
| motor rev | motor rev |
Now we can use the values from ③ and ④ in this formula to identify the needed values for the INC file.
| ⑤ | STEP_SCALE | = | 6,400 | microsteps | X | 1 | motor rev | = | 800 | microsteps |
| motor rev | 8 | mm linear movement | mm linear movement |
Or, expressed in imperial measurements:
| ⑥ | STEP_SCALE | = | 6,400 | microsteps | X | 1 | motor rev | X | 25.4 | mm | = | 20,320 | microsteps |
| motor rev | 8 | mm linear movement | inch | inch linear movement |
| ⑦ | ENCODER_SCALE | = | STEP_SCALE |
Therefore, the entries in the relevant include file are (no commas are used in the include file):
| STEP_SCALE | = | 20320 |
| ENCODER_SCALE | = | 20320 |
Reversing the Direction
If the axis is running in the wrong direction, you can reverse it by making the values negative.
| STEP_SCALE | = | -20320 |
| ENCODER_SCALE | = | -20320 |
Additional Information
Additional information about the files related to the axes is in the Rose Engine Butler Support Manual in the document about Files & Directories.
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