CNC Rotary Mill - Build Specifications
CNC Rotary Mill - FINAL BUILD SPECIFICATION
- Mid-Range Build: $5,000 Budget
-
Table-Mount GRBL Controller Basic Rotary 80/20 Frame
Build Volume: 1524mm × 2438mm × 50mm (60” × 96” × 2”)
Purpose: Foam core shaping for proa hull construction
Configuration: Your exact specifications locked in
YOUR CONFIGURATION SUMMARY
✅ Budget Tier: Mid-range ($5,000)
✅ Controller: GRBL (Arduino-based, free software)
✅ Rotary Axis: Basic ($150 manual table + stepper)
✅ Mounting: Table-mount (no floor stand needed)
✅ Frame: 80/20 aluminum extrusion (bolt-together)
Software Stack (All Free):
- Fusion 360 (free hobby license) - CAD/CAM
- Blender (free) - Mesh editing backup
- OrcaSlicer (free) - You already have it
- OpenBuilds CONTROL (free) - GRBL sender software
COMPLETE BILL OF MATERIALS
SECTION 1: FRAME STRUCTURE (80/20 Extrusion)
1.1 Main Frame Rails
| Item | Specification | Length | Qty | Unit Price | Total | Part # | Supplier |
|---|---|---|---|---|---|---|---|
| X-axis base | 40×80mm extrusion | 2500mm | 2 | $95 | $190 | 4080 | 80/20 Inc |
| Y-axis gantry | 40×80mm extrusion | 1650mm | 2 | $62 | $124 | 4080 | 80/20 Inc |
| Z-axis vertical | 40×40mm extrusion | 400mm | 2 | $15 | $30 | 4040 | 80/20 Inc |
| Gantry crossbeam | 40×120mm extrusion | 1650mm | 1 | $124 | $124 | 4120 | 80/20 Inc |
1.2 Support & Bracing
| Item | Specification | Length | Qty | Unit Price | Total | Supplier |
|---|---|---|---|---|---|---|
| Table supports | 40×40mm extrusion | 1200mm | 4 | $45 | $180 | 80/20 Inc |
| Cross braces | 40×40mm extrusion | 800mm | 6 | $30 | $180 | 80/20 Inc |
| Diagonal braces | 40×40mm extrusion | 1000mm | 4 | $38 | $152 | 80/20 Inc |
1.3 Joining Hardware
| Item | Specification | Qty | Unit Price | Total | Part # | Supplier |
|---|---|---|---|---|---|---|
| Corner brackets | 90° angle, 40-series | 32 | $8 | $256 | 4304 | 80/20 Inc |
| Inside corner | 90° 3-way, 40-series | 8 | $12 | $96 | 4307 | 80/20 Inc |
| T-nuts (drop-in) | M8, 40-series slot | 150 | $0.55 | $83 | 3382 | 80/20 Inc |
| Hex bolts | M8×20mm, button head | 150 | $0.38 | $57 | - | McMaster-Carr |
| End caps | 40-series plastic | 24 | $1.20 | $29 | 2028 | 80/20 Inc |
Frame Subtotal: $1,501
SECTION 2: TABLE/BED
2.1 Spoil Board & Support
| Item | Specification | Size | Qty | Unit Price | Total | Supplier |
|---|---|---|---|---|---|---|
| MDF spoil board | 25mm thick | 1220×2440mm | 1 | $75 | $75 | Lumber yard |
| Bed support ribs | 40×40mm extrusion | 2400mm | 6 | $90 | $540 | 80/20 Inc |
| Mounting feet | Rubber isolation | - | 8 | $6 | $48 | McMaster-Carr |
2.2 Clamping System
| Item | Specification | Qty | Unit Price | Total | Supplier | Notes |
|---|---|---|---|---|---|---|
| T-track aluminum | 2500mm length | 4 | $32 | $128 | Amazon | For clamp mounting |
| Hold-down clamps | Adjustable, T-bolt | 8 | $12 | $96 | Amazon | Foam workholding |
| T-bolt sets | M8×50mm with knobs | 16 | $4 | $64 | Amazon | Quick-adjust |
Table Subtotal: $951
SECTION 3: LINEAR MOTION SYSTEM
3.1 Linear Guide Rails (Semi-Pro Quality)
| Axis | Item | Specification | Qty | Unit Price | Total | Supplier |
|---|---|---|---|---|---|---|
| X-axis | Linear rail | HGR20, 2500mm | 2 | $168 | $336 | Amazon/eBay |
| X | Rail carriages | HGW20CA | 4 | $22 | $88 | Amazon |
| Y-axis | Linear rail | HGR20, 1650mm | 2 | $118 | $236 | Amazon |
| Y | Rail carriages | HGW20CA | 4 | $22 | $88 | Amazon |
| Z-axis | Linear rail | HGR15, 400mm | 2 | $32 | $64 | Amazon |
| Z | Rail carriages | HGW15CA | 4 | $16 | $64 | Amazon |
Linear Rails Subtotal: $876
SECTION 4: DRIVE SYSTEM
4.1 Ball Screws (Z-axis precision)
| Item | Specification | Qty | Unit Price | Total | Supplier | Notes |
|---|---|---|---|---|---|---|
| Z ball screw | 1204 (12mm, 4mm pitch), 400mm | 1 | $42 | $42 | Amazon | Fine control |
| Z ball nut | 1204 single nut | 1 | $22 | $22 | Amazon | Preloaded |
| Z bearing blocks | BK10 + BF10 set | 1 | $18 | $18 | Amazon | 10mm bore |
| Flexible coupling | 8mm to 8mm | 1 | $8 | $8 | Amazon | Motor to screw |
4.2 Rack & Pinion (X/Y speed)
| Item | Specification | Qty | Unit Price | Total | Supplier | Notes |
|---|---|---|---|---|---|---|
| X-axis rack | 10mm pitch helical, 2500mm | 2 | $142 | $284 | CNCRouterParts | Dual rack |
| X pinion gears | 10mm pitch, 20 teeth | 2 | $38 | $76 | CNCRouterParts | NEMA 23 mount |
| Y-axis rack | 10mm pitch, 1650mm | 2 | $95 | $190 | CNCRouterParts | Dual rack |
| Y pinion gears | 10mm pitch, 20 teeth | 2 | $38 | $76 | CNCRouterParts | NEMA 23 mount |
Drive System Subtotal: $716
SECTION 5: STEPPER MOTORS
| Axis | Item | Specification | Qty | Unit Price | Total | Supplier | Notes |
|---|---|---|---|---|---|---|---|
| X-axis | NEMA 23 | 425 oz-in, 2.8A, 1.8° | 1 | $32 | $32 | StepperOnline | High torque |
| Y-axis | NEMA 23 | 425 oz-in, 2.8A, dual | 2 | $32 | $64 | StepperOnline | Synchronized |
| Z-axis | NEMA 23 | 270 oz-in, 2.8A | 1 | $28 | $28 | StepperOnline | Lighter load |
| A-axis | NEMA 23 | 270 oz-in, 2.8A | 1 | $28 | $28 | StepperOnline | Rotary drive |
Motors Subtotal: $152
SECTION 6: BASIC ROTARY 4TH AXIS
6.1 Manual Rotary Table + Stepper Adapter
| Item | Specification | Qty | Unit Price | Total | Supplier | Notes |
|---|---|---|---|---|---|---|
| Rotary table | 6” (150mm) horizontal | 1 | $85 | $85 | Amazon/eBay | Manual indexing |
| Stepper mount | NEMA 23 adapter plate | 1 | $24 | $24 | Amazon | Custom bracket |
| Timing pulley | GT2, 60 tooth | 1 | $12 | $12 | Amazon | Gear reduction |
| Timing belt | GT2, 400mm loop | 1 | $8 | $8 | Amazon | 3:1 ratio |
| Mounting plate | Aluminum 300×400mm×10mm | 1 | $45 | $45 | McMaster | Bolts to table |
| Foam chuck | 3-jaw style, wood lathe | 1 | $35 | $35 | Amazon | Holds foam blank |
Rotary Axis Subtotal: $209
Upgrade path: Can swap to $615 CNC rotary later if needed
SECTION 7: GRBL ELECTRONICS (Free Software)
7.1 GRBL Controller Board
| Item | Specification | Qty | Unit Price | Total | Supplier | Features |
|---|---|---|---|---|---|---|
| Arduino CNC shield | GRBL v1.1, 4-axis | 1 | $45 | $45 | Amazon | Open-source firmware |
| Arduino Uno R3 | Microcontroller board | 1 | $18 | $18 | Amazon | Runs GRBL |
7.2 Stepper Drivers
| Item | Specification | Qty | Unit Price | Total | Supplier | Notes |
|---|---|---|---|---|---|---|
| DM542T drivers | 4.2A, 50V, digital | 5 | $32 | $160 | Amazon | All 4 axes + spare |
7.3 Power Supply
| Item | Specification | Qty | Unit Price | Total | Supplier | Notes |
|---|---|---|---|---|---|---|
| Main PSU | 48V 15A (720W) switching | 1 | $72 | $72 | Amazon/MeanWell | Motors |
| 24V PSU | 24V 3A for logic | 1 | $22 | $22 | Amazon | Controller/sensors |
7.4 Wiring & Connectors
| Item | Specification | Qty | Unit Price | Total | Supplier |
|---|---|---|---|---|---|
| Motor cables | 4-wire shielded, 3m | 5 | $8 | $40 | Amazon |
| Power cables | 14 AWG wire, 10m spool | 1 | $18 | $18 | Amazon |
| Terminal blocks | Screw terminals, 20-position | 2 | $8 | $16 | Amazon |
| E-stop button | Mushroom head emergency | 1 | $16 | $16 | Amazon |
| Enclosure box | ABS plastic, 300×200×150mm | 1 | $28 | $28 | Amazon |
Electronics Subtotal: $435
SECTION 8: SPINDLE & CUTTING
8.1 Budget Router Option (Recommended for Foam)
| Item | Specification | Qty | Unit Price | Total | Supplier | Notes |
|---|---|---|---|---|---|---|
| DeWalt DWP611 | 1.25 HP trim router | 1 | $128 | $128 | Home Depot | Variable speed |
| Router mount | 69mm diameter clamp | 1 | $38 | $38 | Amazon | Z-axis attachment |
| Dust shoe | 2.5” vacuum port | 1 | $24 | $24 | Amazon | Foam dust control |
Spindle Subtotal: $190
Note: Adequate for foam. Upgrade to 2.2kW spindle ($320) later if needed.
SECTION 9: CUTTING TOOLS (Foam-Specific)
| Item | Specification | Qty | Unit Price | Total | Supplier | Notes |
|---|---|---|---|---|---|---|
| Upcut spiral bits | 6mm, 2-flute carbide | 3 | $16 | $48 | Amazon | Fast chip evacuation |
| Ball nose bit | 12mm radius, 2-flute | 2 | $20 | $40 | Amazon | Smooth curves |
| Collet set | 1/4” and 6mm | 1 | $24 | $24 | Amazon | DeWalt compatible |
| Bit storage case | 24-slot organizer | 1 | $16 | $16 | Amazon | Keep bits organized |
Tools Subtotal: $128
SECTION 10: SAFETY & PERIPHERALS
10.1 Essential Safety
| Item | Specification | Qty | Unit Price | Total | Supplier |
|---|---|---|---|---|---|
| Safety glasses | ANSI Z87.1 rated | 2 | $8 | $16 | Harbor Freight |
| Hearing protection | Earmuffs, 31 NRR | 1 | $18 | $18 | Amazon |
| Dust mask | N95 respirator, box of 20 | 1 | $22 | $22 | Amazon |
| First aid kit | 100-piece | 1 | $16 | $16 | Amazon |
10.2 Dust Collection
| Item | Specification | Qty | Unit Price | Total | Supplier |
|---|---|---|---|---|---|
| Shop vacuum | 6 gal, 3 HP | 1 | $75 | $75 | Harbor Freight |
| Vacuum hose | 2.5” diameter, 3m | 1 | $18 | $18 | Amazon |
| Hose adapter | 2.5” to dust shoe | 1 | $8 | $8 | Amazon |
Safety Subtotal: $173
SECTION 11: LIMIT SWITCHES & HOMING
| Item | Specification | Qty | Unit Price | Total | Supplier | Notes |
|---|---|---|---|---|---|---|
| Limit switches | Mechanical, NO/NC | 7 | $4 | $28 | Amazon | 2 per axis + spare |
| Switch mounts | 3D printed or aluminum | 6 | $3 | $18 | Amazon/DIY | Mount to rails |
| Cable harness | Pre-wired with connectors | 1 | $38 | $38 | Amazon | Plug & play |
Limit Switches Subtotal: $84
SECTION 12: MISCELLANEOUS HARDWARE
| Item | Specification | Qty | Unit Price | Total | Supplier |
|---|---|---|---|---|---|
| Grease/lubrication | PTFE spray, rail oil | 1 | $16 | $16 | Amazon |
| Allen key set | Metric, 1.5-10mm | 1 | $12 | $12 | Harbor Freight |
| Cable ties | Assorted, 100-pack | 1 | $8 | $8 | Amazon |
| Labels/markers | Wire labeling kit | 1 | $12 | $12 | Amazon |
| Threadlocker | Loctite 243, medium | 1 | $8 | $8 | Amazon |
Miscellaneous Subtotal: $56
TOTAL BUILD COST SUMMARY
| Category | Subtotal |
|---|---|
| Frame & Structure (80/20) | $1,501 |
| Table/Bed | $951 |
| Linear Rails | $876 |
| Drive System | $716 |
| Stepper Motors | $152 |
| Basic Rotary Axis | $209 |
| GRBL Electronics | $435 |
| Router/Spindle | $190 |
| Cutting Tools | $128 |
| Safety Equipment | $173 |
| Limit Switches | $84 |
| Miscellaneous | $56 |
TOTAL: $5,471
Slightly over budget - see cost optimization below
COST OPTIMIZATION TO HIT $5,000
Option A: Reduce Rail Quality (-$300)
Swap premium linear rails for budget Chinese:
- Current: $876 (Hiwin/PMI quality)
- Budget: $576 (Generic Chinese HGR rails)
- Savings: $300
Trade-off: Slightly more play, but adequate for foam
Option B: Smaller Foam Sheets Support (-$240)
Reduce bed support ribs:
- Current: 6× 2400mm ribs ($540)
- Reduced: 4× 2400mm ribs ($360)
- Savings: $180
Plus reduce T-tracks:
- Current: 4× tracks ($128)
- Reduced: 2× tracks ($64)
- Savings: $64
Total savings: $244
Option C: DIY Some Components (-$200)
Make instead of buy:
- Router mount ($38) → 3D print or fab ($8) = Save $30
- Dust shoe ($24) → DIY from PVC ($5) = Save $19
- Switch mounts ($18) → 3D print ($3) = Save $15
- Rotary mounting plate ($45) → Cut from scrap ($10) = Save $35
- T-bolt sets ($64) → Make from threaded rod ($15) = Save $49
- Foam chuck ($35) → DIY wood chuck ($8) = Save $27
Total DIY savings: $175
RECOMMENDED OPTIMIZATION: A + C
Apply:
- Budget linear rails: -$300
- DIY components: -$175
NEW TOTAL: $4,996 ✅ Under budget!
FINAL OPTIMIZED BOM
| Category | Original | Optimized |
|---|---|---|
| Frame & Structure | $1,501 | $1,501 |
| Table/Bed | $951 | $951 |
| Linear Rails | $876 | $576 ↓ |
| Drive System | $716 | $716 |
| Stepper Motors | $152 | $152 |
| Rotary Axis | $209 | $147 ↓ |
| GRBL Electronics | $435 | $435 |
| Router/Spindle | $190 | $165 ↓ |
| Cutting Tools | $128 | $128 |
| Safety Equipment | $173 | $173 |
| Limit Switches | $84 | $84 |
| Miscellaneous | $56 | $21 ↓ |
OPTIMIZED TOTAL: $4,996 ✅
You have $4 left for beer! 🍺
SOFTWARE (ALL FREE)
Required Software - $0 Cost
| Software | Purpose | License | Download |
|---|---|---|---|
| Fusion 360 | CAD/CAM design | Free (personal) | autodesk.com/fusion360 |
| OpenBuilds CONTROL | GRBL sender/interface | Free/Open-source | openbuilds.com/control |
| Blender | Mesh editing (you have it) | Free/Open-source | blender.org |
| UGS (Universal G-Code Sender) | Alternative GRBL sender | Free/Open-source | github.com/winder/ugs |
| bCNC | Another GRBL sender option | Free/Open-source | github.com/vlachoudis/bCNC |
Recommended: OpenBuilds CONTROL (best UI for beginners)
TABLE-MOUNT SPECIFICATIONS
Your Workbench Requirements
CNC footprint: 2600mm × 1800mm × 600mm (L × W × H)
Workbench needs:
- Minimum size: 2800mm × 2000mm surface
- Thickness: 38mm (2×4 framing minimum)
- Load capacity: 150 kg (330 lbs) machine + materials
- Level surface: ±2mm across entire span
Mounting method:
- Bolt 80/20 frame directly to bench
- Use 12mm lag bolts into bench structure
- Isolate with rubber feet (included in BOM)
No floor stand needed - saves $200+ and floor space
BUILD PHASES & TIMELINE
Phase 1: Frame Assembly (2 days)
Difficulty: Medium
Tools needed: Hex keys, drill, square, level
- Cut 80/20 extrusions to length (or order pre-cut)
- Assemble base frame (X-axis rails + supports)
- Build gantry (Y-axis beam)
- Square and level entire frame
- Bolt to workbench
Phase 2: Linear Motion (3 days)
Difficulty: Hard
Tools needed: Hex keys, feeler gauges, dial indicator
- Mount linear rails to extrusion
- Align rails (parallel within 0.1mm)
- Install carriages and test smooth movement
- Mount rack & pinion (X/Y axes)
- Install Z-axis ball screw
- Align all axes square to each other
Phase 3: Electronics (2 days)
Difficulty: Medium
Tools needed: Screwdrivers, wire strippers, multimeter
- Mount stepper motors to axes
- Wire motors to drivers
- Connect drivers to GRBL board
- Install power supplies
- Wire limit switches
- Test each axis movement
- Mount in enclosure box
Phase 4: Spindle & Rotary (1 day)
Difficulty: Easy
Tools needed: Wrenches, hex keys
- Mount DeWalt router to Z-axis
- Attach dust shoe
- Install rotary table on bed
- Mount NEMA 23 to rotary with belt drive
- Wire rotary axis as A-axis
- Test rotation
Phase 5: Testing & Calibration (2 days)
Difficulty: Medium
Tools needed: Calipers, test material
- Install GRBL firmware on Arduino
- Configure steps/mm for each axis
- Set soft limits in GRBL
- Home machine to zero position
- Test jog commands
- Air-cut test programs
- First foam test cuts
- Tune speeds & feeds
Total Build Time: 10 days for experienced builder, 14 days for beginner
SUPPLIER QUICK REFERENCE
Primary Suppliers (USA)
| Supplier | Products | Website | Shipping |
|---|---|---|---|
| 80/20 Inc | Aluminum extrusion, brackets | 8020.net | 1-2 weeks |
| Amazon | Electronics, tools, hardware | amazon.com | 2 days (Prime) |
| McMaster-Carr | Precision hardware | mcmaster.com | Next day |
| StepperOnline | NEMA motors, drivers | omc-stepperonline.com | 1 week |
| CNCRouterParts | Rack/pinion, mounts | cncrouterparts.com | 3-5 days |
| Harbor Freight | Tools, safety gear | harborfreight.com | Local pickup |
Budget Alternative: AliExpress
50% cheaper but 4-6 week shipping
- Linear rails: $576 → $300
- Stepper motors: $152 → $85
- Electronics: $435 → $250
Total savings: ~$500 if you can wait
NEXT STEPS TO BUILD
Week 1: PLANNING
- ✅ Review this BOM (you’re here!)
- Measure workbench - confirm 2800×2000mm minimum
- Create supplier shopping list
- Budget check - $4,996 total
Week 2: ORDERING
Order long-lead items first:
- 80/20 extrusions (2 week lead time)
- Linear rails from Amazon/eBay (1 week)
- CNCRouterParts rack & pinion (1 week)
Order fast-ship items:
- Motors, electronics (Amazon 2-day)
- Router, tools (Home Depot pickup)
- Hardware (McMaster next-day)
Weeks 3-4: ASSEMBLY
Follow build phases above (10-14 days)
Week 5: TESTING
Calibrate, tune, first foam cuts
Week 6: PRODUCTION
Cut your proa hull!
INCLUDED DOCUMENTATION
I’ll provide separately:
- ✅ Detailed assembly manual with photos
- ✅ Wiring diagrams for GRBL setup
- ✅ GRBL configuration file for your machine
- ✅ First cuts tutorial (foam test pieces)
- ✅ CAM workflow from Fusion 360 to CNC
UPGRADE PATHS (Future)
After Initial Build
Phase 2 Upgrades ($500):
- Touch probe ($215) - Highly recommended
- Upgraded spindle 2.2kW ($320)
- Better rotary chuck ($465)
Phase 3 Upgrades ($1,200):
- Touchscreen pendant ($400)
- Camera system ($70)
- Enclosure panels ($450)
- Premium rotary 4th axis ($800)
Your machine is designed to grow with your needs!
QUESTIONS?
Before ordering, confirm:
- Workbench size adequate (2800×2000mm minimum)?
- Power available (120V 15A outlet)?
- OK with 10-14 day build timeline?
- Comfortable with medium difficulty assembly?
- Budget confirmed at $5,000?
Ready to proceed with:
- ✅ Final optimized BOM ($4,996)
- ✅ Fusion 360 .f3d hull file (coming next)
- ✅ Assembly instructions (coming next)
Let’s build this CNC and cut some foam! 🛶⚙️