Syntax and static rules
grblHAL check mode, line by line, plus twelve rules for what it accepts but should not
Twinwright Studio
A CNC simulator that runs the controller’s own firmware.
Every alarm, every error code, every millisecond of a feed hold behaves the way it will on the MC-1, because it is the same code. Around it, Studio simulates the machine: motors, spindle, cutting, switches and wiring.
Firmware in the loop
Real firmware, not an imitation
Studio compiles the grblHAL core unmodified and runs it on a deterministic virtual clock. The planner, the step generator, homing, probing and every error path are the firmware’s own. A run replays bit for bit, on Windows or Linux.
- Cross-checked against the upstream grblHAL Simulator: identical positions and answers
- Motion alone runs 300–400× faster than real time; with material removal usually several times faster
- The same settings file configures the twin and the MC-1
See the cut
See the cut, not just the path
The workpiece is a height map with a top and a bottom for every cell, so slots, pockets and undercuts come out as they would. Colour it by deviation from your CAD, by feed, force, chip thickness or chatter margin — click any spot to jump to the line that cut it.
- Resolution down to 0.01 mm
- Export the machined part as STL or a height-map PNG
- Compare with a design part at your tolerance
Machine panel
Real panel, real habits
Cycle start, feed hold, overrides and a handwheel, a tool-setter macro that measures tool length, edge-finder probing and single-block stepping. The interface grows with you: five levels from Demo to Researcher show only what that level needs.
- Operator: panel, overrides, MPG, program page
- Technician: workholding, tool setting, diagnostics, fault injection
- Engineer and Researcher: model parameters, curves, data export, branching
Failure training
Practise the bad day
Break a limit-switch wire, make a sensor glitch, trip a drive alarm, press E-stop mid-cut or pull the mains plug. Studio reproduces how grblHAL and the electrics of the MC-1 react, including the ones that are silent and dangerous — and shows the recovery.
- Wire faults: open, short, intermittent, glitch
- Drive alarms, VFD communication loss, power loss and cold start
- Every consequence is from the firmware, not a script
New in 0.1
Write the program here. Let an AI help.
Studio is also where programs are written, debugged and made faster — by you or by an AI assistant working on a twin.
Editor · debugger · optimizer
An editor that knows the machine
Per-line times, twelve static rules, breakpoints on force or chatter, restart from any line, versions, an optimizer and a feature-based generator.
Programming →MCP server · assistant · audit logAI on twins, never on the machine
One click connects Claude, ChatGPT, Cursor, VS Code or LM Studio; or chat in Studio with your own key. Every call is in a hash-chained log.
AI & MCP →Verification
Find the problem before the machine does.
A Studio run is an audit of your program on this machine.
Rapids into material
G0 moves that would cut, found by look-ahead
Spindle not running
cutting with the spindle stopped or still ramping up
Collisions and near misses
tool, shank and holder against vise, clamps, table and tool setter
Soft limits
moves outside the travel, before they raise an alarm
Chatter
stability margin for every cut, with a better spindle speed
Overload
spindle load, VFD current and drive torque against their limits
Part deviation
the finished workpiece against your STL, cell by cell
Five levels
The interface grows with you.
| Demo | Load an example, press cycle start, watch. Gauges and coordinates only. |
| Operator | The machine panel: overrides, handwheel, jogging, the program page. |
| Technician | Workholding, tool setting, probing, diagnostics and fault injection. |
| Engineer | Curves, cut analysis, chatter margin, drive and spindle detail. |
| Researcher | Model parameters and their sources, data export, recordings and branching. |
Automation
Script it, record it, branch it.
A lockstep API gives programs full control of virtual time; a standard-library Python package wraps it. Record any session and play it back on a timeline, open it in Foxglove or PlotJuggler (MCAP) or GTKWave (step pulses as VCD), or branch a new run from any moment of an old one.
Python · lockstep session
from mc1twin import Twin
with Twin(drive="L1") as t: # the MC-1 with closed-loop drives
t.home()
t.setup(shape="block", size=[60, 40, 10], material="6061-T6",
fixture="vise", at=[100, 75])
t.tool("flat 6 n3 L20")
t.job(open("bracket.nc").read(), start=True)
t.until("job", timeout=900) # virtual seconds, runs far faster
print(t.compare(0.02)) # deviation from the design part
print(t.summary()["hash"]["all"]) # identical on every machine
System requirements
- Operating system
- Windows 10 or 11, 64-bit
- Graphics
- Direct3D 11 GPU; software rendering (WARP) as a fallback
- Processor and memory
- Any x64 CPU from the last ten years; 4 GB RAM
- Disk
- About 100 MB with recordings
- macOS and Linux
- Not yet: Studio is a Windows program
- Interface languages
- English and Simplified Chinese built in, switched while running; more languages as language packs, with their units and currency
What Studio does not do (yet)
- It simulates the MC-1. Twins of other grblHAL machines are on the roadmap.
- Three axes. A fourth axis will follow the hardware.
- It is not CAM: the generator covers simple features (faces, pockets, slots, contours, holes, text). Bring complex parts from Fusion, FreeCAD, Carbide Create or any grbl post-processor.
- Model values are design and literature values until the first machines are measured; the Researcher level shows each one's source.
FAQ
Is Studio free?
The preview is free, with every feature. We earn our living from the MC-1, accessories, training and support; the terms of Studio 1.0 will be published before it is released.
Do I need the MC-1 to use Studio?
No. Studio is a complete simulator on its own. Most people will only ever use the twin.
How close is the twin to the real machine?
The firmware is identical by construction. The mechanics, spindle and cutting models use design data and published values today; each will be calibrated against measurements on the prototype machines, and every production MC-1 ships with its own measured twin profile.
Can I use my own CAM?
Yes. Use a post-processor for grbl or grblHAL; Studio reads plain G-code files. Its check names every line this controller would refuse, for example cutter compensation (G41/G42), subprograms or expressions.
Can an AI assistant use Studio?
Yes. Studio has an MCP server built in: switch AI on and connect Claude, ChatGPT, Cursor, VS Code or a local model with one click — see AI & MCP. The AI works on twins, never on a real machine.
Can Studio simulate my Shapeoko, 3018 or other machine?
Not yet. Twins of other grblHAL machines are on the roadmap; tell us which machine you have.