f42d9a35dd
- Added settling-delay parameter (default: 0.15s) to allow mechanical settling after rapid movements - Modified plotter-lod.py to insert settling delay (G4 P0.15) before pen-down command - Updated plotter-lod.inx to expose settling delay in UI - Created POSITIONING_FIX.md with detailed explanation and tuning guide This fixes position offset issues caused by immediate pen-down after rapid travel (G4 P0 -> M3 S1000). New sequence allows motors to stabilize before pen engages, improving drawing accuracy.
2.5 KiB
2.5 KiB
Position Stability Fix for LY Drawbot
Problem Identified
Your G-code showed positioning instability because the machine was not given enough time to mechanically settle after rapid movements before the pen was lowered.
Original G-code sequence:
G1 F3000 # Fast travel to position
G1 X-194.2381 Y40.11
G4 P0 # NO settling delay! ← PROBLEM
M3 S1000 # Pen down immediately
G4 P0.2 # Delay after pen down
G1 F2000.000000 # Start drawing
The G4 P0 provided zero delay for mechanical settling, causing position offsets.
Solution Implemented
Added a new settling delay parameter that allows the machine to stabilize after movement before lowering the pen.
New G-code sequence:
G1 F3000 # Fast travel to position
G1 X-194.2381 Y40.11
G4 P0.15 # 150ms settling delay ← FIX
M3 S1000 # Pen down after settling
G4 P0.2 # Pen-on delay
G1 F2000.000000 # Start drawing
Changes Made
- plotter-lod.py: Added
settling-delayparameter (default: 0.15s) - plotter-lod.inx: Added UI control for "Settling Delay After Movement"
Recommended Settings
Based on mechanical behavior, try these settings:
| Parameter | Recommended Value | Purpose |
|---|---|---|
| Settling Delay | 0.15 - 0.25s | Allow motors/mechanics to stabilize |
| Pen-On Delay | 0.2 - 0.3s | Allow pen to fully engage surface |
| Pen-Off Delay | 0.2s | Allow pen to fully retract |
Tuning Guide
If you still see position offsets:
- Increase Settling Delay to 0.2s or 0.25s
- Test with slower travel speed (reduce from 3000 to 2000)
If drawing is too slow:
- Reduce Settling Delay to 0.1s (minimum recommended)
- Keep at least 0.05s for mechanical dampening
For very precise work:
- Settling Delay: 0.25s
- Pen-On Delay: 0.3s
- Travel Speed: 2000 mm/min
For faster sketches:
- Settling Delay: 0.1s
- Pen-On Delay: 0.15s
- Travel Speed: 3000 mm/min
Testing
After regenerating your G-code with these settings, you should see:
G1 F3000
G1 X-194.2381 Y40.11
G4 P0.15 # ← Settling delay now present
M3 S1000
G4 P0.2
Monitor the first few rectangles in your drawing to verify positioning accuracy.
Additional Notes
- The settling delay is applied before every pen-down operation
- This ensures consistent positioning across all drawing operations
- Slight increase in total drawing time (~10-15%) but much better accuracy
- Can be adjusted per-drawing based on complexity and precision needs