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Thread: something different from galvo scanners?

  1. #1
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    Default something different from galvo scanners?

    Are there something like galvo scanners, but with slightly larger mirrors to allow very wide angles, in cost of very slow speeds? I just want to animate a 6mm beam moving around.

    I've seen motors with mirrors attached to them in some stage lights and cheap lasers, but nothing animatable/controllable I'm looking for.

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    get larger scanners??

    marking mirrors can get pretty huge

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    ... for high DC-power (up to 120Watts@1070nm) laser-melting I've switched from cheap chinese galvos with max 10mm big mirrors to high resolution servos with 45mm big mirrors (could be even bigger).

    With the galvos and BeamConstruct as controlling software I've got something like 10m/s scanning speed on the target, with the servos and Editasc10+firmware as control-software this dropped to around 500mm/s (maybe 30/s), what's enough for my application.

    A video from the first testing:
    https://vimeo.com/95512748

    Viktor

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    General Scanning G330, G330DT, GM20, Cambridge 6810, 6820, 6860, 6840, 6450 all show up on Ebay regularly for cheap.
    Generally, large mirror Galvos have shaft sizes of at least 3.5 mm or more and are slow. But they will be faster, on average then most servos.

    These will move large mirrors:

    http://www.ebay.com/itm/Laser-Scanne...item3f4a929fb7

    One cannot argue with 30$ for open loop scanners capable of 35 mm mirrors.

    PS, He means "Marking Galvo" not marking scanner.

    Steve
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  6. #6
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    ... today I've received a Basel Lasertech galvoscanner for testing - it's an old type from 1984 with General Scanning MG300PDT galvos, but was working well, until one of the two 2x15V transformers produced smoke :-/

    Luckily I have the complete electric/wiring schemes too, so finding+replacing the transformer(s) shouldn't be a big problem - then I'll test the limits ...

    Viktor
    Attached Thumbnails Attached Thumbnails Galvo-head.jpg  

    Driver front.jpg  

    Driver rear.jpg  


  7. #7
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    Quote Originally Posted by VDX View Post
    ... for high DC-power (up to 120Watts@1070nm) laser-melting I've switched from cheap chinese galvos with max 10mm big mirrors to high resolution servos with 45mm big mirrors (could be even bigger).

    With the galvos and BeamConstruct as controlling software I've got something like 10m/s scanning speed on the target, with the servos and Editasc10+firmware as control-software this dropped to around 500mm/s (maybe 30/s), what's enough for my application.

    A video from the first testing:
    https://vimeo.com/95512748

    Viktor

    awesome! i have a strong urge to build a galvo based marking system to augment my laser cutter. so many projects...
    suppose you're thinkin' about a plate o' shrimp. Suddenly someone'll say, like, plate, or shrimp, or plate o' shrimp out of the blue, no explanation. No point in lookin' for one, either. It's all part of a cosmic unconciousness.

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    ... I'm using pretty expensive (around 300€) DC-motors with gearbox and encoder from Maxon motors, but did the same with other motor-/encoder-combinations too.

    For driving them I found servo-drivers (around 40€ or 100€ each), which are controlled with STEP+DIR (like common stepper-drivers) that use the encoder output to position the motors.

    This drivers can run with up to 300kHz STEP frequenzies, but my controller can handle only 100kHz max., so there's some optimization potential left ;-)

    Viktor

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    Is this not a job for stepper motors and DMX?
    The lighting industry seems to think so
    Frikkin Lasers
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    ... you can use steppers too ... even steppers with attached encoders for high accuracy positioning -- I have some 1000steps/rev-steppers running with 20kHz max (or 10x microstepping running with 200kHz max), 5:1 geared and with attached 4096-encoders (4x = 16384 inc/r) ... but this will be even expensiver than servos+drivers :-/

    Steppers are mainly used for their 'fire-and-forget' behaviour when stepping without loosing steps. But if you need higher speeds and/or super fine resolutions/accuracies, then fast DC-motors with encoders are more common than steppers ...

    Viktor

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