Choose 3S when compact carves ship now and you want a live in-stock cell. Choose 4S when 400 mm jobs are already paid and you can wait on the preorder window.
Important differences
Both packages use a 500W spindle; the fork is work area: 300 × 180 × 78 mm on 3S versus 400 × 400 mm on 4S.
4S adds a 3.5-inch touchscreen and dust-shielded motion, but the selected 500W pack is a preorder configuration.
Do not buy 4S travel for hypothetical sheet work while current jobs fit 3S.
Key specifications
Key specification comparison
Spec
ACMER ASCARVA 3S
ACMER ASCARVA 4S 500W
Price range
Current price
$299.00
$499.00
Current price
$588.00
$898.00
EquipmentSelect Score
7.0 / 10
7.2 / 10
Best for
Compact 500W CNC for small parts
Budget 400 mm CNC with touchscreen control
Work area
300 × 180 × 78 mm
400 × 400 mm
Spindle power
500 W
500 W
Spindle speed
12000 RPM
—
Positioning accuracy
±0.025 mm
—
Maximum engraving speed
—
10000 mm/min
Controller
ESP32
3.5 in touchscreen
ACMER ASCARVA 3S
Pros
500W spindle and all-aluminum frame
Tool setter, E-stop, and six limit switches
Candle, UGS, and Easel compatibility across major desktop systems
Limitations
Small 300 × 180 mm X/Y envelope
Open frame requires separate dust, noise, and safety controls
Light soft-metal capability should not be confused with production milling
ACMER ASCARVA 4S 500W
Pros
400 × 400 mm work area with selected 500W upgrade
3.5-inch touchscreen and manual Z control
Dust-shielded motion and pre-assembled delivery
Limitations
Preorder product with estimated shipping rather than immediate fulfillment
Open frame still requires external dust collection and guarding
Published Z travel is not clear enough to use as a comparison claim
Final recommendation
Choose 3S when compact carves ship now and you want a live in-stock cell. Choose 4S when 400 mm jobs are already paid and you can wait on the preorder window.
It is the same spindle-power class with a larger XY, touchscreen control, and a preorder 500W pack. Confirm the exact variant before treating brochure options as interchangeable.
Should I wait for 4S if I need 400 mm now?+
Only if the preorder window fits the first paid jobs. VEVOR S4040 is the live 400 mm peer at 300W if waiting is not acceptable.
Wood CNC work starts with the blanks you ship: plaque size, relief depth, and fixture margin. Shortlist envelope and spindle class before chasing a larger frame you will not fill.
A sub-$500 budget can open compact or 400 mm 300W desktop CNC—but it will not fund a production mill or a waiting 500W 400 mm preorder pack. Use this band to prove paid parts.
Under $1,000 covers the live desktop CNC shortlist: compact 500W, 400 mm 300W, and the 400 mm 500W ACMER pack. Large-format sheet routers sit well above this band.