Dimensional Calibration
Field-tested calibration methods from Ukrainian volunteer production networks.
Scale Factor Calculator
Ukrainian gauge method: Print a test object, measure actual vs target, get correction factor for X/Y scaling.
Flow Rate Calculator
Single-wall method: Print hollow cube, measure wall thickness, calculate new flow rate.
Per CNC Kitchen research: Calibration cubes can make accuracy WORSE if misused.
The correction factor only works at the calibrated size. A 50mm calibration will be off at 70mm.
Root cause is often material shrinkage, not machine calibration. Use slicer shrinkage compensation first.
Shrinkage Compensation
Material Shrinkage Calculator
Compensate for material shrinkage by scaling your model.
OrcaSlicer: Filament Settings → Shrinkage compensation
Cura: Material settings → Horizontal expansion (negative value)
PrusaSlicer: Scale model manually or use modifier
PETG Settings
Recommended material for all operational components.
PETG is the standard for operational components. PLA becomes brittle below 0°C and softens at 60°C. PETG handles temperature extremes, impacts, and outdoor conditions.
PETG Print Parameters
| Parameter | Value | Notes |
|---|---|---|
| Nozzle Temp | 230-245°C |
Sweet spot 235-245°C |
| Bed Temp | 70-90°C |
85-90°C for best adhesion |
| First Layer | 230°C / 85°C |
Nozzle / Bed |
| Subsequent Layers | 240°C / 90°C |
Better layer adhesion |
| Print Speed | 35-50 mm/s |
Balance quality/strength |
| Layer Height | 0.2mm |
Max 2/3 nozzle diameter |
| Layer Width | 0.4-0.8mm |
1-2x nozzle diameter |
| Infill | 30-40% |
For structural parts |
| Fan Speed | 50-70% |
Not 100% like PLA |
| Retraction (Bowden) | 5-7mm @ 35-40mm/s |
Prevents stringing |
| Retraction (Direct) | 2-4mm @ 35-40mm/s |
Shorter path |
Material Comparison
| Property | PLA | PETG | ABS |
|---|---|---|---|
| Heat Resistance | 55-60°C | 80-90°C | 95-105°C |
| Impact Strength | Low (brittle) | High (flexes) | Medium |
| Outdoor Use | Poor | Good | Good |
| Print Difficulty | Easy | Medium | Hard (warps) |
| Enclosure Needed | No | No | Yes |
| Shrinkage | ~0.35% |
~0.4% |
~0.7% |
| Field Use | Not recommended | Recommended | Acceptable |
From Ukrainian field manual: "When heated to 60°C it loses hardness; when cooled it becomes brittle."
Do not use PLA for operational components. Use PETG.
Vase Mode
Spiral printing reduces production time by 50-67%.
Vase mode (spiral printing) reduces print time by 50-67%. Ukrainian volunteers use this for mass production of stabilizer fins and similar components.
Time Comparison
| Mode | Time | Method |
|---|---|---|
| Standard | 40 min |
Layer-by-layer with infill |
| Vase Mode | 13-19 min |
Continuous spiral, single wall |
Slicer Configuration
Cura Settings
PrusaSlicer Settings
OrcaSlicer Settings
Speed/Cooling Balance
For thin areas (like fin tips), standard settings cause undercooked plastic. Enable dynamic cooling:
| Parameter | Setting | Purpose |
|---|---|---|
| Normal Fan Speed | 50-70% |
Standard cooling |
| Max Fan Speed | 100% |
When layer time < threshold |
| Min Layer Time | 2-3 sec |
Triggers max cooling |
| Print Speed | 25-30 mm/s |
Slower for vase mode |
| Temperature | +5-10°C |
Better adhesion, no stringing risk |
Vase Mode Time Estimator
Estimate time savings when switching to vase mode.
Essential Equipment
Required tools for calibration and production.
-
Digital calipersCritical for calibration
-
Hex key set (quality)Not cheap kit tools
-
Nozzle wrenchFor hot removal
-
Spare 0.4mm nozzlesConsumable item
-
0.6mm, 0.8mm nozzlesFor vase mode / faster prints
-
Needle for nozzle cleaning
-
Fine tweezers
-
Quality SD cardReliability critical for long prints
-
Small flashlight
-
Brass cleaning brush
-
1kg PETG minimumStarting material
Pre-Print Checklist
-
Bed leveled / tramwayed
-
Nozzle clean (no debris)
-
Filament dry (no moisture)Critical for PETG
-
Bed surface clean
-
Correct material profile loaded
-
Enough filament for print
-
First layer monitored
Quality Control
Acceptable Tolerances
| Check | Tolerance | Action if Failed |
|---|---|---|
| XYZ Cube Dimensions | ±0.1mm |
Re-calibrate |
| Wall Thickness | ±0.05mm |
Adjust flow rate |
| Test Fit (gauge) | Seats firmly | Adjust scale factor |
| Layer Adhesion | No delamination | Increase temp, slow down |
Troubleshooting
| Problem | Likely Cause | Solution |
|---|---|---|
| Stringing | Temp too high / retraction | Lower temp 5°C, increase retraction |
| Poor adhesion | Bed temp / gap | Increase bed temp, level bed |
| Layer separation | Temp too low / speed | Increase temp, slow down |
| Warping | Cooling / bed temp | Reduce fan, increase bed temp |
| Dimensional error (X/Y) | Belt tension | Check/adjust belts |
| Dimensional error (Z) | Lead screw / steps | Check lead screw, calibrate Z |
| Over-extrusion | Flow too high | Reduce flow 2-5% |
| Under-extrusion | Flow too low / clog | Increase flow, clean nozzle |