Darkly Labs Community

E2 cutting timber

I have 200 washers to cut from 4.55mm Victorian Mountain Ash timber. Not the most exciting job!  I decided to do some testing to get the settings that would give the most efficient cutting without manual intervention to finish off the cutting. (Sometimes I use a scalpel to complete cutting as required.) 

Cutting on the E2 - 150mm/min 100% power x 4 passes sees the washers cleanly drop out of the material. Pretty good.

I tried running two passes at normal focal setting and dropping the Z axis by 2mm then running two more passes. It was no where near  cutting through the material. So, leaving the focus setting at the optimum calculated by initial focus tests, seems the best option for cutting efficiency.

1 Like

Hi Daryl, interesting that dropping the Z axis doesn’t actually provide any benefit to cutting power, I would have though that dropping the Z axis and effectively moving the laser back to the optimum height from the material (I.e. The laser groove) would be a better option.

Did you clean up the washer? I note the lack of charred edging.

Yeah not sure why Richard.  I have carried out previous tests and also reached the same outcome.  Something to do with the profile of the laser beam I suspect.

I did clean the washer with a quick rub of 320 grit paper.  I work exclusively with timber and always clean my work as part of my finishing process.

 

 

Hi Daryl,

I too work with timber and only have the A3 emblazer1 4 watt model.

I notice that you assumed the height above the workpiece doesnt seem to affect the potential to cut any deeper than what the focal length of the beam is.

In other posts I have found this to be true and its the focus thats the most important. I just recently added a low tech form of air assist to my emblaser 1 and it seems to be beneficial. Before I had to run the head at 8 mm /sec to stop burning on the surface. . Now I can run at 4 mm/sec and not get any burning.This allows for fewer passes but takes longer. I have tried 2mm Jacaranda and red cedar with some success but any thicker seems beyond the capabilities of the laser. (The lighter jacaranda cuts better than the red cedar).

Did you have the emblaser 1 before the emblaser 2 and if so what were your best results when cutting thicker material.

And how often do you need to clean the lense

John Tomley

Hi John,

Yes theoretically if you start out with focal length optimum for the material surface, run some passes and lower the head a little so the optimum focus is say 1 mm below the material surface, then you would think you could cut deeper.  This theory (of mine) in practice does not seem to work. I do own an E1 and have tried the same test with no positive outcome on that as well.

Focus is critical on both the E1 & E2. I spend a lot of time trying to get it right.  I have to say much easier with the E2.

Air flow certainly helps John. I use an El Cheapo room fan at the back of the E1 blowing across the work and get very little smoke contamination and better results.

I never clean the lense on the E1.  However, the E2 does need cleaning depending on material used.  I think the problem lies in glues and chemicals in manufactured timber.  I have just run a very large job (E2) on Vic. Mountain Ash with no lens contamination. If I run MDF, which I now wont do on the E2, different story.

I can cut up to 4.5mm on my E1 with a 4W head.  300mm/min 100% 4 passes. Most timbers cut really well but I have had some that don’t even have the surface scratched by the E1.  Tasmanian Tiger Myrtle is one that doesn’t cut.  

Again, the CRITICAL thing for good cutting of timber is OPTIMUM focus.

Cheers

Daryl

P. S.  Said I’d been busy :slight_smile:

 

 

 

 

 

1 Like

Daryl,

Its interesting that you dont clean the lense on the E1. I am having to clean after about 1 hour of cutting. Most of the cuts are on Balsa ply 2.5mm thick.

Would you guess that its the smoke not getting away from under the shield and if so (Maybe Domenic has a thought) would cutting a piece from the bottom of the shield help. I understand that I would need a different height gauge but I could make one of those easily. My E1 is enclosed inside a box about 200 mm deep. Air enters through a filtered hole across from the side. and extracted from opposite side.

Also what do you use to clean the E2 lense.  I notice that there is a lense cleaning kit available but I dont think I can get it under the head . Tried glass wash, isopropol alchol and spectacle cleaner liquid. Similar results.

John

John,

I have never worked with Balsa so not sure if this is causing an issue for you…but I think probably not . It may  be due to the fact that your E1 is enclosed.  I run my E1 with a cheap household type fan placed at the rear of the unit blowing across the work.  This aids cutting and also blows the smoke away from the lens.

Also, I’m assuming that your laser head fan is working OK. 

I use isopropyl alcohol and felt buds.  They look like cotton buds but are more robust and less hairy.  I also use a small lamp and inspection mirror so I can see exactly what I’m doing.

As  the E1 is such a small lens to clean it’s difficult to do in situ.  My choice would be to remove the head and clean the lens.  That way you don’t have to disturb the focus setting. Not sure if cutting a section of the shroud will help. As you suggest Domenic may have an answer.  You could always purchase another shroud, modify it and give it a test.

When you state that you have used various cleaning agents with “similar results” do you get the lens clean and then it gets dirty again?

If I was in your position John, first thing I would do is run the machine without the enclosure and see if that helps.

Cheers

Daryl

Daryl,

Yes the lense seem to get dirty very quickly. or it seems that way.

The best results I have had is when I use the spectacle cleaner. I suspect that it contains a cleaning agent and it dries fairly quickly. If I clean ,(With a cotton bud) after each cut, (The job I’m working on has about 2 metres of vectors to cut) an internal cut will drop out after 2 or 3 passes,  (4 mm/sec @ 100 %  x 4 passes). I uses an extra pass to ensure the job is cut right through. Across the area of the job (200 x 170 mm ) there are still bits of the lower veneer not cut through. I then have to use a scalpel to clean up the uncut areas.

If the problem is with the smoke not being cleared away (There is no smoke evident when I look through the protective perspex top of the enclosure) then I suspect that the consistency of the balsa ply is at fault. I dont think the height of the ply is a problem as i tape it down to a flat sub board. As in other tests the height of the head above the job not seem to affect the cutting appreciably.

I will try a job outside the enclosure and see it that helps.

Thanks John

Are you running the 3W or 4W head John?  

Daryl,

My emblaser is the 4 watt model.

I tried running a job with the enclosure open to the air after a previous job and I did not clean the lense befoehand.

The focus is still good with a kerf width of about.02 mm. The kerf only shows a slight burning and gain in width after the 4th  pass.

The jog cut through after 3 passes in 90% of the spots. I had to finish off the rest with a scapel…

I notice than when cutting with the scalpel the charred section is a lot harded than the original material. Do you think that I am almost “Welding” the pieces back together, and maybe less power and faster rae might solve the problem.The other solution is to find a material (Wood) that will cut well.

John

John,

What are you sitting your material on? You do need air flow underneath your work I believe. I use an Melamine base board and screwed in a matrix of round head screws so the material sits on the screw heads. I also hold the material down with round head screws around the perimeter of the material. I use the same method with the E2.  I just mount the material outside the machine and drop the base board and material into the Emblaser.  I also use the centre of my material as the datum by marking an X with pencil and align the material centre by jogging the head to centre and switching the laser on. Then align the base and material to the X mark.

I am using Plyco 2.85mm Poplar ply and have gone from the hair pulling days as you are suffering to having to all 100% cut.

I don’t think you are “welding” the pieces back together and less power faster speed will not give better results.

I’m happy to send you a sample piece of the poplar ply to try John.  I think I overdone my last order - 22 x 1200 x 600 sheets so I have a bit spare. :slight_smile:

Daryl

 

This is my battle scarred base board.

 

 

 

Daryl.

I have a false bed in the laser that consists of a bed of nails that has been sanded flat,].

On top of the nails I have a sheet of stainless security mesh that lays about 1mm below the point of the nail.

This allows for air to pass through and escape from under the material. (See diagram)

The mesh keeps the very small pieces from falling down and getting stuck in the next pass

Opening the lid on my enclosure seem to give a slightly better result (About 10% better)

Thanks for you offer of the ply, but I will contact Plyco and see what they have that will suit my needs.

Thanks again for replying an taking time to sympathise

John

image.jpg

Project just completed in 2.5 mm ply. The ply is best as it is strong for the thickness as wood would break easily in small pieces.