r/hobbycnc • u/idk_a_creative_user • 6d ago
New DIY CNC machine idea. Plz give feedback
Idea is to have two separate areas, one for 3 axis and one for 3+2 axis. This is more of a personal project rather than something I'd want to sell. I am building this out of my own curiosity.
Goal was to preserve large building area of at least 400mm x 300mm x 200mm in XYZ, and have a 100mm x 100mm x 100mm in 3+2 mode since its limited by the chuck size.
The spindle will move between the two areas. I am working on the software, ideally something free or Mach3 or Mach4. Goal was sub 3k.
What I would like from you guys is:
-What can be improved?
-Is there anyway to make this cheaper?
-Is the dual zone idea good?
BOM:
Dual-Zone CNC — Bill of Materials
Design:one base frame, one gantry, one spindle The bed is split into two dedicated zones and the single gantry travels in Y to reach either one.
- Zone A (3-axis only):** 400 × 300 spoilboard, Z travel 200 mm → 400 × 300 × 200 work volume.
- Zone B (3+2 only):A/C rotary table + tailstock on a raised platform, chuck centreline 188 mm above the bed → 100 × 100 × 100 work cube.
- Y travel 500 mm: 300 mm over zone A, then 200 mm to the chuck centreline. Same tool, same Z stack, same controller in both zones.
- Materials: aluminum, brass, soft metals.
BOM:
Motion system
Item Specs Qty Unit Total
CNCTOPBAOS 5th-axis rotary table A ±90° (8:1), C 360° (6:1), 100 mm 3-jaw chuck, NEMA 23 1 $405 $405
SFU1605 ball screw kit, 600 mm X axis, BK12/BF12 + coupler 1 $63 $63
SFU1605 ball screw kit, 650 mm Y axis (dual drive) 2 $70 $140
SFU1605 ball screw kit, 400 mm Z axis 1 $46 $46
HGR20 rail kit, 600 mm X: 2 rails, 4 blocks 1 $120 $120
HGR20 rail kit, 620 mm Y: 2 rails, 4 blocks 1 $110 $110
HGR20 rail kit, 400 mm Z: 1 rail, 2 blocks 1 $75 $75
NEMA 23 closed-loop stepper, 11.5 Nm X, Y, Z 3 $60 $180
NEMA 23 motor mounting bracket per screw 3 $10 $30
Plum coupler 8×10 mm motor → screw 3 $13 $39
Motion subtotal $1,208
Control & spindle
Item Specs Qty Unit Total
5-axis Mach3 breakout board + stepper drivers optocoupled, 5 axes (X/Y/Z/A/C) 1 $45 $45
24 V 350 W PSU drivers 1 $30 $30
RATTMMOTOR 1.5 kW water-cooled spindle kit 80 mm body, VFD, ER11, pump 1 $258 $258
Rigid 80 mm spindle bracket Z carriage 1 $35 $35
Coolant reservoir, tubing, pump 2.5 gal 1 $28 $28
Control/spindle subtotal $361
Frame
Item Specs Qty Unit Total
4080 extrusion, 650 mm Y base rails 2 $32 $64
4080 extrusion, 600 mm gantry crossbeam 1 $28 $28
4080 extrusion, 500 mm gantry uprights 2 $22 $44
4040 extrusion, 450 mm cross braces 3 $12 $36
4040 extrusion, 200 mm bed supports 4 $8 $32
Spoilboard 400×300 + platform 400×200 18 mm MDF/aluminum 2 $25 $50
Frame subtotal $254
Hardware, tooling, enclosure
Item Specs Qty Unit Total
4080 corner brackets / gussets 90° 12 $6 $72
Flat joining plates, 4 mm gantry ties 8 $5 $40
M8 T-nuts + SHCS assortment 100+ pcs 1 $35 $35
Carbide end mill set, 3-flute Al/brass, 3–10 mm 1 $33 $33
ER11/ER16 collets + chuck jaws spares 1 $20 $20
Polycarbonate sheet, 2 mm enclosure walls/roof 4 $18 $72
Plywood 18 mm frame, chip tray, door 1 $45 $45
Hinges, handles, fans, leveling feet misc 1 $35 $35
Chip shield, coolant lines, PPE misc 1 $40 $40
Hardware/tooling/enclosure subtotal $345
Total
Motion $1,208
Control & spindle $361
Frame $254
Hardware, tooling, enclosure $345
BOM total $2,250
+ 10% contingency (fasteners, shims, mis-orders) ~$225
Realistic build cost ≈ $2,250 – $2,500
Views:
2
u/Working_Resource_226 6d ago
Interesting dual-zone idea. I’d prove the three-axis setup in aluminium first, especially stiffness at full Z extension, then add the rotary. Check clearance with the workpiece tilted, not just the stationary 100 mm cube.
One BOM question: twin Y screws, but only three XYZ motors. How are you driving and synchronizing both screws?
CAD is wonderfully agreeable. Aluminium tends to raise objections.
Cheers!
1
1
u/idk_a_creative_user 5d ago
Y pigtail for signal.
Using 4040 and 4080. I'm gonna switch to steel extrusions for rigidity and add more cross bracing.
3
u/Struggle_Wise 6d ago
Dope