SainSmart PROVerXL 4x4 vs Sienci Labs AltMill MK2 4x4
Two desktop CNC routers side by side, using each maker's own specs, checked 4 November 2026 and 1 November 2026. We haven't tested either one, so this compares what the makers publish, not how well they cut.
Photo: SainSmartSainSmart PROVerXL 4x4
$3,599.00
Where they differ
- Sienci Labs AltMill MK2 4x4 is listed $439 lower ($3,160.00* against $3,599.00).
- SainSmart PROVerXL 4x4 has the larger published X × Y work area: 1300 × 1300 mm against 1245 × 1245 mm (1.1× the area).
- Sienci Labs AltMill MK2 4x4 lists more Z: 140 mm against 118 mm.
- SainSmart PROVerXL 4x4 doesn't say whether one is included; Sienci Labs AltMill MK2 4x4 doesn't include one.
- Published footprints: 1,893 × 1,842 mm against 1,499 × 1,575 mm.
Published specs
| SainSmart PROVerXL 4x4 | Sienci Labs AltMill MK2 4x4 | |
|---|---|---|
| Price | $3,599.00 | $3,160.00* |
| Work area | 1300 × 1300 mm | 1245 × 1245 mm |
| Z | 118 mm (4.6") | 140 mm (5.5") |
| Spindle or router | Unclear: the spec table lists a 710W AC spindle, but a photo caption says "710W Spindle (Not included)" and the FAQ says to provide a 65 mm trim router or spindle. | Not included; standard 80 mm spindle mount only. Optional 1.5 kW and 2.2 kW ER20 spindle kits and a 2.2 kW ATC kit. |
| Drive | Ball screws: X and Y 20 mm, Z 12 mm | Ballscrews on all axes |
| Linear guides | HG20 linear guides on Y, HG15 on X and Z | HGR15 linear guides on all axes |
| Controller and motors | 32-bit board, GRBL 1.1h. Closed-loop NEMA 23 steppers. | SLB-EXT controller with e-stop. Closed-loop steppers; "over 600IPM". |
| Software | GRBL senders such as Candle and UGS; Genmitsu app for wireless control | Not published |
| Footprint | 1893 x 1842 x 617 mm | 59″ wide × 62″ deep |
| Weight | 150 kg (330.7 lb) | 76 lb |
| Warranty | One year | 120 days from receipt |
| Spec conflicts | 1 | None found |
| Source | Maker’s page ↗ | Maker’s page ↗ |
Work areas to scale
Open in the compare tool See them on your bench
Why this pair
Pairs are picked by a rule: machines in the same size class and within about 60% of each other's price, plus each machine's nearest sibling from the same maker. No search or keyword data was used. All 61 pairs.
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