Hello
As an offspring of the halfnote laser thread, a few people have asked for pics of the construction of my two laser moving heads, based on these halfnote heads, and Martin Mac250 lighting fixtures..
I got these two defective lighting fixtures a few years back, and a lot of work had to get done on them to even get the pan/tilt movement working..
Back then my plan was to feed the laser light to them by a fiber, so i mounted some G120 galvos in them and a friend and i tried to make our own galvo amps for them..
However the amps never got to working really good, and G120s are not really good scanners, so the project was given up.. (also partly because i got ripped off by the guy i bought the laser that was supposed to power the fibers from)...
So everything was pulled apart again, and so the new build started..
I had to rewire the whole fixture because some of the wiring was worn out, so that was the first task..
and then i had to get all the power supplies for the head, laser galvos etc. fitted into the base of the fixture.. not much extra space there..
All in all the base contains psus producing the following voltages: 13Vac 5A, 11Vac 2A, 30Vac 8A, +24Vdc 3A, -24Vdc 3A, 12Vdc 10A, 5Vdc 40A.
Then it was time to mount the laser in the head.. i had to drill and tab new holes in the halfnote baseplate to mount new cooling (two 90W TECs and 2 powerfull PC CPU coolers) - it doesnt really feel good to take a drillpress to something as delicate as this, but it had to be done.. I also had to cut a corner off the baseplate to be able to fit it inside the head..
The halfnote laser is hanging on rubber shock absorbers, and the galvo drivers are mounted on top. The two nylon angles are for holding the galvos, so they move with the laser, but are not electrically connected..
More wires to connect...
On the back of the head, at the top is a solid state relay for controlling the TEC. The plate it is mounted on, will touch a heatsink on the external shell, so this will cool both the galvo drivers and the SS-relay.
Below is the switching driver for the laser diodes, and still hanging in the wires is the omron temp. controller, that controls the SS-relay and thus the TECs.
And offcourse - everything has to be done twice.. i am building two projectors
Here the back shells have been mounted and most of the wiring is done..
Then it was time to power up and adjust temperatures, rise times, currents and all that stuff, and make sure that everything was working like supposed..
Galvo mount, mirror and other last bits being mounted..
And finally the galvos are mounted and adjusted, and the last few plastic shells are mounted..
And FINALLY, two completely assembled lasers..
THEY WORK.. that called for a bit of celebration
All in all this has been an interesting project, and i have learned a whole lot.. however considering the amount of time and money that has been put into this, it would be a lot easier and cheaper to just buy a commercial product..
It may look easy, when looking at the pics, but the pics does not tell about all the things that were made, that did not work out (making a psu solution and blanking took more than half a year, because my first plan was to make my own constant current source, and then use AOM blanking, but that presented some space and temperature problems, so in the end i decided to modulate the diodes in stead.. Also many many many hours have been spent cutting out pieces of the original lighting fixture, drilling holes, making new parts out of nylon, plastic or aluminum, and test fitting and testing all the different parts..
I think i have some more pics of the cooling setup and the KTP temp controller somewhere.. i will try and dig them up and post them also...
I hope this was fun and interesting reading
Regards, Simon