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Thread: Motorized Dichro mirror mounts?

  1. #11
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    Jul 2006
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    Belgium
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    I bought these steppers to use instead of a thumbscrew on an mm1:
    https://nl.aliexpress.com/item/40003...27424c4dJvYvEy
    Trying to create a good diode mount....

  2. #12
    Join Date
    May 2021
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    Megastructure
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    Heloo,
    In this way you may prefer more precision 28BYJ-48 steppers cuz of 1/64 ratio and hight precision of 0,18°. Here they can be bought with ULN driver for Arduino. In some way you can use LV8729 on your duino-board to achive full 1/128 stepping.
    Click image for larger version. 

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    It will looks like that with some 3d-printed magic:
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    Last edited by Methelina; 05-24-2021 at 07:04.
    Best regards,
    Linda

    Discord: Linda#7591

  3. #13
    Join Date
    Jul 2010
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    Netherlands
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    Quote Originally Posted by polishedball View Post
    I have a couple i bought surplus that I used in a lumia build to just walk the beam. I'll dig it out and get some photos.
    Interested.
    Please do show them when you can.

  4. #14
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    Jul 2010
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    Quote Originally Posted by Bradfo69 View Post
    Basically, the technology is, rather than having to pop the cover off to do an alignment, (which could be a bitch if it's up on a truss in a ceiling somewhere) these dichros are motorized to be able to correctly lay red, blue green on top of each other. (Rather than having to futz with allen keys too.) I forgot how exactly but, it sounds like Pangolin has built controls into Beyond that can "talk" to those mounts and get them to move up down, left right to fix an alignment issue. I've only heard about them being in Kvant projectors.

    Actually... here. :-) https://www.youtube.com/watch?v=fw6Pz2nTQVM

    Yes and also to keep the projectors sealed.. Opening a laser projector up in a non clean enviroment or wanting to keep them truly waterproof means you really shouldn't open up a projector.. Or opening a projector up in a foggy room is not good..

    One thing of driving with a stepper directly is resolution issues and microstepping means no. Holding torgue..it would take nothing to get horrible misalignment or have Vibrations interfere with the alignment... You need something that provides some friction

  5. #15
    Join Date
    Nov 2008
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    Cleveland Ohio
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    Quote Originally Posted by Methelina View Post
    Heloo,
    In this way you may prefer more precision 28BYJ-48 steppers cuz of 1/64 ratio and hight precision of 0,18°. Here they can be bought with ULN driver for Arduino. In some way you can use LV8729 on your duino-board to achive full 1/128 stepping.
    Click image for larger version. 

Name:	d20eda62fe9205f3c39d05574fd366ea37851087.jpeg 
Views:	3 
Size:	45.1 KB 
ID:	58016

    It will looks like that with some 3d-printed magic:
    Click image for larger version. 

Name:	OWRogCe.gif 
Views:	42 
Size:	3.01 MB 
ID:	58017 Click image for larger version. 

Name:	ntDCaa4.gif 
Views:	40 
Size:	4.76 MB 
ID:	58019
    AHH I see no torque issue because you move the photons not the source! But now you have 4 galvo sets! RGB and XY. Killing a fly with a sledge.

    Those are the parts from the flexure microscope I was thinking of. PJ you are right about torque but the thing is you can gear down from a faster stepper to get torque and also more effective resolution. Steps are steps but if you shrink the spacing on those steps through gearing you get finer resolution. In fact you can take through just three gears a very small torque and make a monster you can't turn with your fingers.

    It's like a timebase based on 10mhz clock. If you divide down to seconds its about 23 divide by 2's. each time you double the accuracy/precision. different but related quantities.

    Anyway so maybe the point is use a faster turning servo with less steps you gear down. We only use a very small part of the full movement. Get it close by hand then engage the system.
    I see this as a nice I2C application.

    Hey in fact how is this for making it complicated. Use a 1% beam splitter. IE a glass slide. Use a prism to break the beam into the three colors. Have that hit a one dimensional detector array from like cheap spectrophotometer. Use that info to make a closed loop feedback to keep the beams where you want them. Use a second one to pickup on the y axis or just a ccd array in general. Now it auto finds the center of the beam, overlaps, matches the divergence of each beam (using the ccd array you can profile the beam). Now go make it work....see you in a lifetime.

  6. #16
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    Gearing down indeed provides some resistance in the gears but lets not forget that there are issues like backlash and tolerance issues with gears.. it might be a non issue I am not sure!
    Most certainly would worth trying though!

  7. #17
    Join Date
    Jun 2009
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    Quote Originally Posted by masterpj View Post
    Gearing down indeed provides some resistance in the gears but lets not forget that there are issues like backlash and tolerance issues with gears.. it might be a non issue I am not sure!
    Most certainly would worth trying though!
    Picomotors will do the job, but they're expensive.
    "There are painters who transform the sun into a yellow spot, but there are others who, with the help of their art and their intelligence, transform a yellow spot into the sun." Pablo Picasso

  8. #18
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    Nov 2008
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    I like the idea of an xy set of mirrors. Not killing fly with hammer. I think you could use linear actuators to turn set screws on a worm gear. They don’t have to be fast. You could use a single motor and gearing to go between the two sets. Remember one stays constant. If you arrange it right all you do is rotate a gear to go between the sets of worm gears. The worms move an arc with a mirror. Think inside out section of a gear on a pivot point with a mirror glued to it. One motor per axis or now it’s a manual knob on top of the projector and you are the motor.

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