This is the manual of Studio 1.0.2, an earlier version. The manual of the latest version
Documentation 1.0.2 Technical manual
MC-1 hardware
_Draft (round 14): the text is being written; the sections may still grow._
The MC-1 as it is designed: the figures in this chapter are design values. Each built machine is to be measured at commissioning, and its twin set to what was measured (see Machine profiles).
The machine
The MC-1 is a desktop three-axis mill for aluminium, brass and engineering plastics. Its gantry is fixed; the table moves in Y, the gantry's carriage in X, the spindle in Z.
| Travels X / Y / Z | 200 / 150 / 80 mm |
| Table | 300 × 220 × 35 mm, M6 tapped holes on a 25 mm grid |
| Size, width × depth × height | about 508 × 490 × 564 mm, with motors, cable chains and levelling feet, without the control box |
| Mass | about 57 kg, without the control box |
| Frame | 6061-T6 aluminium plates, bolted |
| Linear guides | HIWIN HGR15 rails (6), HGW15CC flange blocks (12) |
| Ball screws | SFU1204 (12 mm, 4 mm lead), C7, on BK10 / BF10 supports |
| Motors | NEMA 23 closed-loop steppers, 1.2–1.3 N·m (3), with jaw couplings |
| Spindle | 800 W, water-cooled, Ø65 × 195 mm, ER11 collet |
| Control box | a separate box beside the machine, on its right |
Axes and drives
Each axis is a closed-loop stepper driving its ball screw directly through a jaw coupling. The drives report a fault on one line: the three drives' alarm outputs are wired in series to the controller's motor-fault input, so a drive that faults, or loses its power, stops the machine with an alarm.
The design's fastest moves are 3000 mm/min in X and Y and 1500 mm/min in Z.
Limit switches and homing
Five M8 inductive switches mark the ends of travel: one at each end of X and of Y, each on its own input, and one on the Z slide for both ends of Z. The switches are normally closed: a broken wire or a loose plug reads as a triggered switch, so the controller raises an alarm and refuses to home instead of driving into the end stop.
Homing runs Z first, then X and Y, each towards its positive end (X+, Y+, Z+). The machine must be homed after power-on.
Z and gravity
The Z slide carries the spindle, about 6.35 kg. While the drives are powered they hold Z. When they are not powered (after an E-stop, a drive fault or a power cut), Z with the spindle can creep down.
⚠ Warning
After an E-stop or a drive fault, home the machine again before you continue. Do not reach under the spindle while the drives are off.
Commissioning includes a test with the drives switched off: if Z creeps, the machine gets a Z motor with a brake, or a counterweight.
Spindle
The spindle is a water-cooled 800 W motor spindle, Ø65 × 195 mm with an ER11 collet, two poles, up to 24 000 rpm. A Huanyang HY01D523B drive (VFD, single-phase 220 V in) runs it; the controller sets its speed and reads its state over RS-485, through an isolating module. A water pump cools the spindle.
- The drive's fault relay is wired into the motor-fault line too: when the drive trips, the controller stops the program with an alarm instead of feeding a stopped tool into the work.
- On an E-stop the drive loses its power with the drives, and the spindle runs down by itself (it is not braked).
Controller and wiring
The controller is a Teensy 4.1 on a T41U5XBB carrier board, with opto-isolated inputs. It runs the Twinwright controller (kernel), compatible with the Grbl 1.1 serial protocol, and it connects to the computer over USB.
| Input | What is on it |
|---|---|
| Limits | X−, X+, Y−, Y+ and Z, five inputs |
| Probe | the tool setter and the touch probe |
| E-stop | the E-stop button's second contact |
| Motor fault | the three drives' alarm outputs and the spindle drive's fault relay, in series |
| Cycle start, Feed hold | the buttons SB2 and SB3 on the control box |
Power
Mains goes through a circuit breaker. A 24 V supply is always on: it feeds the controller, the sensors and the control circuit, so the controller stays connected to the computer and reports the E-stop. A contactor (KM1) switches the 48 V supply of the drives, the spindle drive and the pump.
The control box's buttons
Four Ø22 buttons on the control box's door, seen from the front:
| left | right | |
|---|---|---|
| top row | SB1 power on (green) | SB0 E-stop (red) |
| bottom row | SB2 cycle start (green) | SB3 feed hold (yellow) |
- SB1 power on closes KM1, which then holds itself. After an E-stop or a power cut the machine does not power up by itself: release the E-stop and press SB1 again.
- SB3 feed hold does what your sender's feed hold (
!) does: the axes stop under control, the spindle keeps running. It sits under the E-stop, so a hand that misses the E-stop hits feed hold, not cycle start. - SB2 cycle start continues, as your sender's cycle start (
~) does.
Caution
Feed hold is not a safety function. To stop the machine for safety, use the E-stop.
Tool setter and touch probe
The tool setter sits at the table's left rear, held by two M6 screws in the grid; it takes the corner of the work area at about X 0–57, Y 130–150 mm. The tool setter and a touch probe share the controller's probe input.
With Z at the top, the tip of a tool that sticks out 15.5 mm from the collet is 80 mm above the table, and the spindle's nose 130 mm. A longer tool's tip is lower by its extra length. A touch probe held in an ER collet is usually 60–90 mm long from the nut to the stylus tip: with Z at the top, such a probe clears only low setups, about 20 mm above the table for a 70 mm probe.
Studio checks this for you: when you set up the work, change a tool or edit the tool table, it compares the setup's highest point with each tool's tip at the top of Z and says which tool does not clear and by how much.
Workholding
The table's M6 holes on a 25 mm grid take clamps, a subplate or a vise. The twin knows a 75 mm self-centring vise on a 10 mm aluminium subplate, parallels, strap clamps, double-sided tape and a V-block.
- With the vise on its subplate, the jaws' tops are about 66 mm above the table, so a part held in the vise stands about 71 mm high or more.
- For parts you want to probe, use a low setup: strap clamps on the subplate (the stock's top 15–30 mm above the table), or a low vise. A touch probe does not fit above a part held in the 75 mm vise.
- Taking the 10 mm subplate away gives tools 10 mm more room; for a touch probe it is not enough.
Safety
- E-stop (SB0): it opens the contactor's coil circuit, which switches off the drives, the spindle drive and the pump, and tells the controller through its second contact. The axes and the spindle lose power; the spindle runs down by itself; Z may creep down (see Z and gravity). Releasing the E-stop does not restart anything: press SB1, wait for the drives to start, reset the controller and home.
- Faults: a drive fault, a spindle drive trip, or a broken limit switch wire stops the machine with an alarm.
- Feed hold is a controlled stop for the work, not for safety.
- The MC-1 has no enclosure. Keep away from the spindle while it turns and while the axes can move, wear eye protection, and fit bellows or brush covers over the X and Z screws against chips.
- None of the machine's safety functions uses AI, and the AI assistant in Studio is not a safety function.
What is measured at commissioning
The design values above are to be checked on each built machine, and its twin set to what was measured:
- each limit switch's trigger point (inductive switches swept from the side can trigger about 2 mm later than drawn), then the homing pull-off and the soft limits;
- the drives' alarm outputs: unplugging one, or switching off the 48 V, must give an alarm;
- the Z test with the drives switched off;
- the spindle drive's parameters, a run-up on the drive's panel without load, then control over RS-485;
- the control box: the E-stop and SB1 as above, every limit switch and the tool setter unplugged one by one (each must give an alarm), and the panel buttons.
How the twin takes the measured values: Machine profiles.