Timeline for Optics to correct focal distance across a plane
Current License: CC BY-SA 3.0
24 events
| when toggle format | what | by | license | comment | |
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| Jun 25, 2019 at 10:02 | vote | accept | Tom | ||
| Jun 23, 2019 at 15:02 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Feb 16, 2019 at 13:02 | history | bumped | CommunityBot | This question has answers that may be good or bad; the system has marked it active so that they can be reviewed. | |
| Oct 28, 2016 at 18:07 | answer | added | Paul | timeline score: 0 | |
| May 8, 2016 at 7:03 | history | tweeted | twitter.com/StackPhysics/status/729205086388400128 | ||
| Apr 15, 2016 at 10:05 | answer | added | Peter Fry | timeline score: 1 | |
| Apr 13, 2016 at 10:11 | history | edited | Tom | CC BY-SA 3.0 |
New suggestion.
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| Apr 11, 2016 at 17:55 | comment | added | Tom | @Carl: perhaps. But I'm not sure how possible that is with the inexpensive (relatively) components involved. Two concerns: first, how to form a collimated beam at all from that laser source. Secondly, whether the mirrors on the galvo can stand the power density. Actually the second point is a concern anyway and I'm still trying to get information from the supplier on the spec of the mirrors it comes with. | |
| Apr 11, 2016 at 17:42 | comment | added | Carl Witthoft | How about you form a small diameter collimated beam instead? Then you don't have to worry about delta focal length. | |
| Apr 11, 2016 at 15:40 | answer | added | Peter Diehr | timeline score: 0 | |
| Apr 11, 2016 at 15:22 | comment | added | Peter Diehr | Let us continue this discussion in chat. | |
| Apr 11, 2016 at 15:22 | comment | added | Peter Diehr | You would have to translate this downstream lens in coordination with the galvos; this seems much more difficult than a slight fore-and-aft motion required to keep the path length constant. | |
| Apr 11, 2016 at 14:38 | comment | added | Tom | I guess another option is to focus the beam as near infinity as possible (ie as near a collimated beam as possible) and then put a lens downstream of the galvo. Any thoughts? | |
| Apr 11, 2016 at 13:58 | comment | added | Peter Diehr | I worked in a lab with a similar project. This was how they did it; the servo program was calculated in advance for the servo and the galvos; then kept in synch. | |
| Apr 11, 2016 at 13:04 | comment | added | Tom | Overall I was hoping that it'd be possible to use another lens to make the beam focused across a plane rather than a sphere - as I said in the question, one option is to make the galvo far enough away from the build plane that it approximates a sphere, but that leads to an awkwardly large machine. | |
| Apr 11, 2016 at 13:02 | comment | added | Tom | @garyp: Looking to use a laser module such as this: [uk.civillaser.com/… to cure UV-sensitive resin in a top-down SLA 3D printer. The laser module has variable focal length but it's not quickly variable (though I guess it'd be possible to rig up a servo mechanism to the focus adjustment). Obviously the print quality is going to depend on how exactly the beam can be focused on the print surface. | |
| Apr 11, 2016 at 12:58 | comment | added | Tom | @PeterDiehr: Not a bad thought, though since the galvo is capable of ~30kpps it'd have to be a very fast servo loop moving a relatively heavy laser module (the lens is built into the laser module). | |
| Apr 11, 2016 at 12:47 | comment | added | Peter Diehr | Program a servo to move the lens forward as the beam travels a longer path; you will have to calculate the path length as a function of the angle, and use that for the program. | |
| Apr 11, 2016 at 12:30 | comment | added | garyp | Can you tell us more about your application ... especially why the native spot size of the laser is too large. Knowing what you are trying to accomplish will help. | |
| Apr 11, 2016 at 12:16 | comment | added | Tom | No. The plane is the bottom of an SLA printer - a flat print surface is more or less a requirement. | |
| Apr 11, 2016 at 11:50 | history | edited | Kyle Oman | CC BY-SA 3.0 |
deleted 1 character in body; edited tags
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| Apr 11, 2016 at 11:40 | comment | added | Farcher | Can the plane become curved so that the distance is sensibly constant? | |
| Apr 11, 2016 at 11:40 | review | First posts | |||
| Apr 11, 2016 at 11:49 | |||||
| Apr 11, 2016 at 11:34 | history | asked | Tom | CC BY-SA 3.0 |