Model label: GalvoScanAssby
Assembly instructions
Overview:
Y1 - Mirror with 30 degree stroke. This is the first mirror in the path of the laser. This moves in the same direction as the resonant scanner.
Y2 - Mirror with 40 degree stroke. This is the second mirror in the path of the laser.
X - This is the third, smaller galvo mirror.
From left to right: Galvo driver box; in the back driver boards for X, Y1, Y2. Galvo holder with galvos and alignment jig (note pentaprism). Galvo holder with galvos and alignment jig without Y2 mirror (note nacked shaft).
General:
Set up galvo driver box
Build alignment jig. Glue pentaprism on alignment rig
Mount galvo mirrors on shafts - this should be done with torque wrenches to specs provided from Cambridge Tech
Recommended torques for galvo mirrors and galvos
14 mm x mirror .05” screw socket, 2 inch-pounds torque
20 mm x mirror 1/16” screw socket, 3.8 inch-pounds torque
y mirrors 140 inch-pounds torque
x mirror 110 inch-pounds torque
For this entire procedure: zero the X, Y inputs to the galvos – this can be done with a 50 Ohm terminator or short circuit
Setup alignment laser
Wire up and turn on galvos
Do alignment
1) Slide in 30 deg stroke (written on back) and 40 deg stroke (written on back) and 3rd galvo into mounting block. Push galvos all the way into mount.
2) Attach first mirror to galvo. Remove the shafts the galvos come on for shipping. Push mirror all the way along shaft.
3) Couple a test laser beam into the pentaprism, level and parallel to hole pattern on table. Beam should be roughly horizontal (does not matter too much with pentaprism). Use target card with target in position of pentaprism. Adjust position of entire apparatus such that the back reflection goes along the same vertical plane.
4) Zero the inputs to the galvos – this can be done with a 50 Ohm terminator or short circuit
5) Hook up Y1 first. Power up galvo driver (make sure no faults - LED turns green). Note that X cable / Y cables have different endings. Make sure to put mirrors on before turning galvos on.
6) Set Y 1 voltage offset to 1.5V (position sensor for Y1; BNC on the galvo driver box) (which is approximately 6 V on the input).
7) Rotate angle of Y 1 mirror such that the reflected beam is coming out at an 8° angle up with respect to the table.
8) Do fine adjustment of voltage offset to hit 8° exactly (voltage in this instance was 1.511 V; 2nd time 1.587 V). GETTING THE Y MIRROR RIGHT IS IMPORTANT
9) Mount the other Y 2 mirror, adjust position so beam perpendicular; position singal is at -4.8mV
10) adjust X angle so that beam emerges level with table; note position signal is at 0.6 mV