Image: Sienci Labs
Sienci Labs LongMill MK2.5 30x30
Sienci Labs
Best for: A well-supported mid-range woodworking machine with a genuinely good free software stack
Typical starting price
$1,650Editorial baseline for this machine
Overall score
Best current buying path
Where to buy
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- Check manufacturer site for availability
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Quick verdict
The LongMill MK2.5 is the current version of Sienci's long-running mid-range machine, and if you have been reading about the MK2 that is the previous revision. Lead screws and a steel gantry put it above the belt-driven machines at similar money without reaching AltMill territory. The real differentiators are the SuperLongBoard controller and gSender, which Sienci gives away free and which is better than most senders you can pay for.
Who this fits best
A well-supported mid-range woodworking machine with a genuinely good free software stack
Buy this if
A well-supported mid-range woodworking machine with a genuinely good free software stack. SuperLongBoard controller is a genuine step up from a basic GRBL board.
Skip this if
Lead screws are slower than ball screws and wear over time, and steel gantry on aluminium rails is not as rigid as a linear rail machine.
What else you still need
A trim router or the AutoSpin spindle, a table, dust shoe and clamps. Most owners also add a proper wasteboard.
Material reality check
A wood and plastics machine first. Aluminium is possible with patience, but lead screws and steel gantries are not built for regular metal work.
Better alternative if...
you plan to cut aluminium regularly. See Sienci Labs AltMill MK2 2x4
Where it wins
- SuperLongBoard controller is a genuine step up from a basic GRBL board
- Free gSender software that is better than most paid senders
- Lead screws rather than belts at this price
- Strong documentation and Canadian support
- AutoSpin T1 router spindle launched February 2026 as a quieter option
Where it falls short
- Lead screws are slower than ball screws and wear over time
- Steel gantry on aluminium rails is not as rigid as a linear rail machine
- Not a match for the AltMill if you plan to cut metal
- Router not included in the base price
- Existing MK2 documentation and reviews can be confusing against the MK2.5
Specifications
762 × 762 mm
5806 cm²
710W
Trim router user supplied, or the Sienci AutoSpin T1
SuperLongBoard (SLB) running grblHAL
34 kg
$1,650
mid range
Full specification table
Relative to database
Benchmark Scores
Overall Score
Composite across 5 dimensions
Community Sentiment
We have not summarised owner feedback for the Sienci Labs LongMill MK2.5 30x30 yet, so this section is intentionally left without claims. Check the sources for current owner discussions.
Community sentiment is aggregated from forums, Reddit, Discord, and manufacturer communities. Individual experiences may vary.