Nyt on CNC-foorumin tukeminen helppoa!
Maksu onnistuu PayPalin kautta myös kortilla
Konemies kiittää

Ehdota kone/laite/hilavitukutin/työkalu talvi projektiksi -DIY 30W Kuitulaser

Aloittaja Snowfly, 16.10.17 - klo:16:47

« edellinen - seuraava »

0 Jäsenet ja 1 Vieras katselee tätä aihetta.

Snowfly

Rakennan täysin kaikki ite komponenteista lähtien... laser moduuli, jäähdytys, driveri, kuitureititys yms...
Ens viikolla tulee kuitutarvikkeita niin pääsee jatkaan...

Tähän projektiin ei kannate ryhtyä ellei löydy kuituhitsaus vehkeitä paksulle kuidulle... tuossa käytetään 105/125um kuitua...

Arto Juujärvi

Minkä tehoinen laser pitäisi olla jotta voisi leikata ohutta vaneria.

Snowfly

Lainaus käyttäjältä: Arto Juujärvi - 03.02.18 - klo:07:43
Minkä tehoinen laser pitäisi olla jotta voisi leikata ohutta vaneria.
Määrittele ohut vaneri 0.5mm/1mm/3mm/5mm/8mm?
Lisäksi onko tarkoitus leikata harrastukseksi jolloin leikkuuajalla ei ole väliä... vai osaksi tuotantoon jollon ajalla on väliä...
Nämä asiat vaikuttavat ratkaisevasti kuinka tehokkaan laserin tarvitsee...

Arto Juujärvi


Snowfly


Snowfly

Laserin suunnitelun lomassa tuli niputettua tämä 4-akselikin nippuun...
Testiajoa vaille...

Nema 42 30Nm moottori... riittää vääntö vaikka pyörittäisi vähän nopeampaakin ;)

Snowfly

Laseria koeponnistettu ilman optiikkaa ja homma tähän mennessä ok...

Seuraavaksi optiikan suunnittelu, joka ei ole yksinkertaisimmasta päästä...
Tähän vaikuttavat mm. aallonpituus ja laserin teho mikä asettaa tiettyjä vaatimuksia linsseille...

Tämä rajasi kiinalaiset/jenkkiläiset halvemmat linssit pois, koska näiden tehonsietokyky loppui 12-15W tienoilla...

Alustavasti linssi maksaa thorlabsilla 100-200e riippuen otetuista ominaisuuksista...

Lisätään tähän sitten teoriaa jotka löytyvät thorlabsin sivuilta:

Lainaa
Choosing a Lens
Aspheric lenses are commonly chosen to couple incident light with a diameter of 1 - 5 mm into a single mode fiber. A simple example will illustrate the key specifications to consider when trying to choose the correct lens.

Example:
Fiber: P1-630A-FC-2
Collimated Beam Diameter Prior to Lens: Ø3 mm

The specifications for the P1-630A-FC-2, 630 nm, FC/PC single mode patch cable indicate that the mode field diameter (MFD) is 4.3 μm. This specification should be matched to the diffraction-limited spot size given by the following equation:

Here, f is the focal length of the lens, λ is the wavelength of the input light, and D is the diameter of collimated beam incident on the lens. Solving for the desired focal length of the collimating lens yields

Thorlabs offers a large selection of mounted and unmounted aspheric lenses to choose from. The aspheric lens with a focal length that is closest to 16 mm has a focal length of 15.29 mm (Item# 354260-B or A260-B). This lens also has a clear aperture that is larger than the collimated beam diameter. Therefore, this aspheric lens is the best option given the initial parameters (i.e., a P1-630A-FC-2 single mode fiber and a collimated beam diameter of 3 mm). Remember, for optimum coupling the spot size of the focused beam must be less than the MFD of the single mode fiber. As a result, if an aspheric lens is not available that provides an exact match, then choose the aspheric lens with a focal length that is shorter than the calculation above yields. Alternatively, if the clear aperture of the aspheric lens is large enough, the beam can be expanded before the aspheric lens, which has the result of reducing the spot size of the focus beam.

Lainaa
Choosing a Collimation Lens for Your Laser Diode
Since the output of a laser diode is highly divergent, collimating optics are necessary. Since aspheric lenses do not introduce spherical aberration, they are commonly chosen when the collimated laser beam is to be between one and five millimeters. A simple example will illustrate the key specifications to consider when choosing the correct lens for a given application.

Example:
Laser Diode to be Used: L780P010
Desired Collimated Beam Diameter: Ø3 mm (Major Axis)

The specifications for the L780P010 laser diode indicate that the typical parallel and perpendicular FWHM beam divergences are 10° and 30°, respectively. Therefore, as the light diverges, an elliptical beam will result. To collect as much light as possible during the collimation process, consider the larger of these two divergence angles in any calculations (i.e., in this case use 30°). If you wish to convert your elliptical beam in to a round one, we suggest using an Anamorphic Prism Pair, which magnifies one axis of your beam.



From the information above, the focal length of the lens can be determined, using the thin lens approximation:



With this information known, it is now time to choose the appropriate collimating lens. Thorlabs offers a large selection of aspheric lenses to choose from. For this application the ideal lens is a -B AR-coated molded glass aspheric lens with focal length near 5.6 mm. The C171TMD-B (mounted) or 354171-B (unmounted) aspheric lenses have a focal length of 6.20 mm, which will result in a collimated beam diameter (major axis) of 3.3 mm. Next, check to see if the numerical aperture (NA) of the diode is smaller than the NA of the lens:

0.30 = NALens > NADiode ≈ sin(15°) = 0.26

Up to this point, we have been using the FWHM beam diameter to characterize the beam. However, a better practice is to use the 1/e2 beam diameter. For a Gaussian beam profile, the 1/e2 diameter is almost equal to 1.7X the FWHM diameter. The 1/e2 beam diameter therefore captures more of the laser diode's output light (for greater power delivery) and minimizes far-field diffraction (by clipping less of the incident light).

A good rule of thumb is to pick a lens with an NA twice of the NA of the laser diode. For example, either the A390-B or the A390TM-B could be used as these lenses each have an NA of 0.53, which is more than twice the approximate NA of our laser diode (0.26). Note that these lenses each have a focal length of 4.6 mm, resulting in an approximate major beam diameter of 2.5 mm.


Lainaa
Aspheric Lens Design Formula
Positive Radius Indicates that the Center of Curvature is to the Right of the Lens
Negative Radius Indicates that the Center of Curvature is to the Left of the Lens

Aspheric Lens Equation

Definitions of Variables
z   Sag (Surface Profile)
Y   Radial Distance from Optical Axis
R   Radius of Curvature
k   Conic Constant
A4   4th Order Aspheric Coefficient
A6   6th Order Aspheric Coefficient
An   nth Order Aspheric Coefficient
The target values of these constants are available by clicking on the Info Icons below or by viewing the .pdf  and .dxf files available for each lens. Links to the files can be found under the Drawings and Documents tab or by clicking on the part number in the price tables below.




Powered by EzPortal
SMF spam blocked by CleanTalk