need big mirror scanners, speed is least of concerns

[Nii]

Need big mirror scanners to fit 6.5mm beams.
Not going to use for graphics projections, just beams. Speed can be in the <10K range and still would work.

EMS 7000 and 8000 series look like they could fit 7mm beams, but they are fast scanners and for that reason probably are priced accordingly (>$1000)
I have around $450 for this in my pocket and the less I'd spend on scanners the better.

DT20H and PT-A20 look like scanner that could fit the bill. Does anyone have experience with these?
How about another option, replacing small scanner mirrors with bigger ones on scanners not meant for big mirrors but running them very slow (less than half of their dedicated scanspeed)? Is that also an option?

[VDX]

... I've built some "XY-servo-scanners" with DC-motors and encoders - hera a test with the first type:

https://vimeo.com/95512748


It was only so slow because of the super-high gearing ... something like a 400:1 gear-box on the motors ...

Viktor

[Nii]

That's interesting, but I'd prefer if we'd talk about options among (ilda) scanners before a custom diy motors which are controlled with different software/hardware and need a custom mount.

[VDX]

... before starting with the servos, I changed the mirrors on the cheapest chinese galvos I could find to 8x8, 10x10 and 15x15 mirrors - for the 15x15 I had to mill a custom holder and reduce the speed and change the 'damping' trimpot to reduce resonancies.

This worked too, but after cracking the 15x15mm mirrors for too high laser power I've switched to the servos.

Viktor

[catalanjo]

Old GS 300 series scanners will take whatever size mirrors you want to use !
Cheers

[Nii]

Old GS 300 series scanners will take whatever size mirrors you want to use !
Cheers

Interesting. What is their speed and do they need different type amps?

... before starting with the servos, I changed the mirrors on the cheapest chinese galvos I could find to 8x8, 10x10 and 15x15 mirrors - for the 15x15 I had to mill a custom holder and reduce the speed and change the 'damping' trimpot to reduce resonancies.

Did you test how fast you could run them with those mirrors? Or did you just ran them the speed you needed for your CNC project?

[VDX]

Did you test how fast you could run them with those mirrors? Or did you just ran them the speed you needed for your CNC project?

... did you mean the galvos with bigger mirrors or the servos?

With the 10x10mm mirrors on the galvos it was fast enough to project a frame, but with 15x15mm it starts to wobble and making funny noises, so I had to slow them drastically down.

With the servos this is another thing - there were 500lpi encoders on the motors, so 2000 'clicks' per turn, but only 40kHz max. clocking speeds with the small drivers I've used there (but have others with up to 300kHz encoding/clocking capacity).

This will give max. 20rps or 1200rpm of the motors at full speed (around the speed of a fast stepper) ... and with the attached gearboxes and around 180mm focus distance I've got 'engraving' speeds of roughly 300mm/s max. with this setup ...

Viktor

[Nii]

With the 10x10mm mirrors on the galvos it was fast enough to project a frame, but with 15x15mm it starts to wobble and making funny noises, so I had to slow them drastically down.

Interesting since you say you used the cheapest galvos you could find.
I wonder whether I can go bigger with something like PT40 or DT40 and a 20KPPS scanspeed.
I'll need narrower but longer mirrors than 10x10. Any particular reason you used a square 10x10mm mirror instead of something more common?

And by the way, were the mirrors 1mm or thicker?

[slicklasers]

Pangolin Compact 506 with 8mm aperture, with Laser Fantasy Amps… Will cost a little more than the coin in your pocket, but will have a nice setup when done.

[VDX]

... I've cut the mirrors from a bigger 0.7mm thick piece, so could make any shape I want/need.

This "symmetrical" was only for ease of assembling/glueing and later use without predefining X or Y galvos.

You can use any galvo with bigger mirrors, when driving them slow enough ... for the galvos I've used an "Easylase LC USB" DAC from here - http://www.mylaserpage.de/DACs.html

The software was BeamCOnstruct from HAlaser with a self programmed flow-plugin to import HPGL-files and free adjust of speed and "pixel"-resolution ...

Viktor