5 Point Test: MIRA

Applies to: MIRA 5, MIRA 7 and MIRA 9

This guide shows how to run a 5 point test on a MIRA. The test is a good way to find out why the machine is not cutting or engraving, and a final check after you have gone through the full alignment.

What you need

Painter’s tape
2.5 mm Allen key

Run the test

Power the machine on and let it reset fully.
Jog the laser head to the center of the bed, within 5 mm:

Machine X Y

MIRA 5 250 mm 150 mm

MIRA 7 350 mm 225 mm

MIRA 9 450 mm 300 mm
Press a 1” to 2” piece of painter’s tape firmly into the nozzle, so it forms a divot. The divot shows where the beam hits in relation to the edges of the nozzle hole.
Close the lid and quickly press PULSE on the keypad.
Open the lid and gently remove the tape from the nozzle, without touching the divot or the pulse spot. Do not fold or rotate the tape. Its orientation matters, because the position of the pulse mark tells you which adjustment to make. Drawing a small arrow on the tape helps you keep track of direction.
Inspect the pulse mark. Look at its shape, and at where it sits in relation to the center of the divot.
Adjust the alignment as needed, using the process below, to bring the pulse mark as close to the center of the divot as possible. After every adjustment, always pulse into a fresh spot on the tape to see where the mark has moved.
Once the pulse is centered in the divot at the center of the bed, put a fresh piece of tape on the nozzle as in step 3.
Pulse the machine at 5 points, moving the tape each time to match where the machine is being pulsed: the center of the bed, the back left corner, the back right corner, the front left corner and the front right corner.
Inspect the results. If all the pulses hit the same spot across the bed, the 5 point test is complete.

Machine	X	Y
MIRA 5	250 mm	150 mm
MIRA 7	350 mm	225 mm
MIRA 9	450 mm	300 mm

Adjust the pulse mark

The alignment knobs on the Mirror 3 bracket do two jobs: the general alignment of Mirror 3, and the fine positioning of the pulse mark in a 5 point test. In the Mirror 3 alignment procedure, the lens housing is removed from the laser head. Here the lens stays in place, so the adjustments need more precision.

Note: Make every adjustment in reference to the center pulse point. Only run the full 5 point test once the center pulse mark is acceptable.

Each direction has its own brass alignment knob and set screw, shown circled in the photos below. Move the auto focus sensor wire out of the way as needed. The knob turns a different way depending on the direction:

To move the pulse mark	Turn the alignment knob
Left	Loosen slightly (counterclockwise)
Right	Tighten slightly (clockwise)
Down	Loosen slightly (counterclockwise)
Up	Tighten slightly (clockwise)

The steps are otherwise the same for each direction:

Slightly loosen the set screw with a 2.5 mm Allen key.
Loosen the lock nut on the brass alignment knob.
Turn the alignment knob slightly, in the direction given in the table.
Tighten the lock nut.
Tighten the set screw.
Put a fresh piece of tape on the nozzle.
Pulse in the center of the bed.
Remove the tape and inspect the position of the pulse mark.
Repeat until the pulse mark is centered in the divot.

Caution: Do not overtorque the set screw. The threading in the laser head strips easily. A stripped thread leaves the machine impossible to align, and the main chassis of the laser head then has to be replaced. The screw should be firm, and the mirror bracket should not wiggle.