Darkly Labs Community

Emblaser 2 Laser Geometry

Hiya Dominic,

 

So, seen a few posts of people able to cut through 4.5mm MDF etc.

I have tried the same settings used for 4.5mm MDF and I can’t even cut through 2.6mm MDF.

Something I have noticed right from the word go when I first received my laser is the geometry of the laser as it focuses.

See Attached Picture

Now bearing in mind the laser with it in manual jog and specifically defocused.

The laser appears to be focused in a rectangular shape, approximately twice as long (Y axis) as it is across (X axis), with the actual cutting spot half way up the Y axis and 2/3 across on the X axis (To the right).

That doesn’t seem right to me and has bugged me for a while.

I also am noticing now that I am starting to branch out into hobby jobs with stuff other than stainless steel (Awesome by the way) then in MDF my cuts are not equal.

When cutting along the Y axis, I have a much thinner cut than when I am cutting along the X axis, Makes for a caligraphy kind of cut especially when doing nested circles and curves.

This fatter x cut and skinnier Y cut would correspond to the defocused shap I am seeing of the spot geometry.

I am assuming the spot should be round, and that maybe during shipping something came adrift or the like.

Some assistance in this matter would be greatly appreciated, and if something needs replacing, well, it has been this way since shipping so I would assume a warranty issue mayhaps.

Kind Regards

  • Kevin, your Spectrumark and Stainless Guinea Pig

 

Hi Kevin,

Sit back for light lesson 102.

The beam produced by a laser diode is rectangular. The more powerful the diode, the more rectangular, or anamorphic the shape is. This is a result of the componentry within the diode that creates the laser light.

We do our best to ‘reshape’ the laser beam through our optics to achieve a square beam, which can be focused more efficiently. Perfect squareness is not possible without great losses, hence this becomes a balancing act.

There is nothing wrong with your beam shape as you have photographed. This is the beam not in laser mode. Once the diode starts producing a laser beam, it is not possible to determine the actual effective area by photography. You need specialised equipment to analyse the laser beam.

So in short, there is nothing wrong with your laser beam shape. As laser diode technology increase in power, we can start to sacrifice some of that power to create a more perfect beam shape.

As we work through new diode technologies and develop better beam reshaping optics, you will be able to upgrade your lens system in the E2 very easily. We have put a great deal of thought into this. The modular lens housing and diode assembly has been designed with this in mind. Basically anyone can update their laser diode or lens system without sending the machine back to the manufacturer or a technician being involved. The electronics will self adjust to the different laser diode units automatically for you, providing just the right amount of power for optimal and safe operation.

 

Just to add my 5 cents worth regarding your issues cutting MDF, if you haven’t already then try  cleaning your lens - it  makes a huge difference to the cutting results,.

Good advise Chris. 

This is the latest cleaning process:

https://darklylabs.zendesk.com/hc/en-us/articles/115000624351-Deep-Lens-Cleaning-Process

Hiya all,

Thanks Domenic, was sure there was a reason behind it. While waiting for a response (very quick might I add) I did disassemble the lens assembly and do a deep clean. Haven’t run it again.

I noticed the lens assembly notch is elongated. Mine is located towards the top of the notch placing the lens assembly as far from the diode as possible. Would inserting the lens assembly in deeper have any effect and if so what would the effect be?

Having never used diode lasers it kind of explains why the output from the Side Pumped Laser Diode we were considering buying has a rectangular cutting area.

I have only used industrial CO2 lasers previously and that is a round laser beam.

Always a learning experience.

-Kevin

Your lens assembly should be slid in all the way so the o-ring forms a seal with the heatsink.

if the o-ring is not making a seal, then you will start getting dimes into the heatsink chamber, causing the buildup on the upper surface of the lens.

This is great Information. I clean my lens regularly but have yet to deep clean it. I need the new lens cleaning kit. I definatley notice the differance, especially in being able to cut through 3mm ply in two passes without burning.

So Domenic, do tell about these new developments in diodes and lenses. Maybe a more powerful diode that will cut 3mm ply in one pass, all the way through? Maybe a diode that could etch clear glass and cut clear acrylic?

Hi David,

We are constantly working on improving performance. Whether it be new diodes becoming available through to how we can tweak the existing lens geometry.

The most likely improvements you will see will be with cutting performance and speed. One of our team members has a PhD in optics/physics and has been tackling extracting more performance from the current setup. This traditionally turns into a cost vs performance situation. Whilst cutting 3mm plywood in one pass is certainly achievable, it may not be viable if the optics cost more than the whole machine.

Working with transparent materials is entirely different. This would involve a significant change in the type of laser we use along with changes to components such as the lid for safety. Having said that, we have some r&d ideas planned to possibly find a suitable solution to this.

Vague enough?

 

 

The big test will be the ability to cut Bunnings ply in one pass… Thats a PhD all on its own!

 

Hey David,

In response to your sentence about “Maybe a diode that could etch clear glass”:

I was using a sheet of clear glass as a flat surface for cutting some card stock and noticed that what I thought were soot lines were actually etched.  I changed to thin paper and was able to get some fairly decent results.  I think the heat of the paper burning off creates small chips off the surface. 

It does leave the glass darker in the etched areas, as if there’s soot left on the surface even after cleaning, but I can feel that the surface texture of the glass has changed.

I didn’t spend a lot of time on it, and unfortunately I don’t remember the exact settings, but the results I saw in the few minutes I spent on it indicate that it can be done, and probably better than the couple of attempts I did.  Might be worth a try.