Need Help!- CO2 laser cutting white acrylic- burns

[VBLietuva]

Hi all
I have a problem cutting white acrylic with 60w laser engraver. When cutting the laser leaves black burns on the side of acrylic( picture attached) I tried :
1. Cut by 2 times with less speed or power
2. I tried to set corner power 0, 50 and 100, but not much help from that too
3. The acrylic should be good qualitty too, because I tried few tipes, but same problem

I almost lost my hope... I bought this laser to cut acrylic mostly, and white, cream acrylic should be one of my favorites...


Please help me with advices, what could be a problem with white acrylic

[SkipW]

Have you tried raising the acrylic above the cutting bed a little by putting maybe 1/4" pieces of wood under it? Maybe you are getting flash burn when the beam reflects off of the metal cutting grid sections.

Or, does the material come with the protective paper on it? Could you cut it first and remove the paper when done?

Maybe you could attach one of the drawings you use so that we could look at it also.

Regarding the corner power, if I'm cutting acrylic at 60 power, I set the corner power to 59. I don't know if that actually helps or not but that is how they cut acrylic in the demo video I received with my laser. They set the corner power one less than the main power setting.

Try raising it above the cutting grid a little, that might help.

Skip

[EXLASer]

Hi,

Try to set corner power 40.

And another way go to adjust the air assist a little on laser head,

I don't know which kind compressor you use, if those doesn't work out, I suggest you to consider a professional compressor.

Regards
Mike
mike@xyz-tech.com
www.xyz-tech.com

Originally Posted by VBLietuva Hi all I have a problem cutting white acrylic with 60w laser engraver. When cutting the laser leaves black burns on the side of acrylic( picture attached) I tried : 1. Cut by 2 times with less speed or power 2. I tried to set corner power 0, 50 and 100, but not much help from that too 3. The acrylic should be good qualitty too, because I tried few tipes, but same problem I almost lost my hope... I bought this laser to cut acrylic mostly, and white, cream acrylic should be one of my favorites... Please help me with advices, what could be a problem with white acrylic Attachment 97064

http://www.cnczone.com/forums/attach...1&d=1263018580

[VBLietuva]

[QUOTE=SkipW;715623]Have you tried raising the acrylic above the cutting bed a little by putting maybe 1/4" pieces of wood under it? Maybe you are getting flash burn when the beam reflects off of the metal cutting grid sections.
I'm cutting acrylic in same way- I put 0,5cm pieces of wood in the corners. The acrylic is cutting in the air- no touch with table

Or, does the material come with the protective paper on it? Could you cut it first and remove the paper when done?
I tried cutting with transfer paper, but the problem is not on acrylic surface, but in the cuting border or how it says. Sorry for my english
Maybe you could attach one of the drawings you use so that we could look at it also.

Regarding the corner power, if I'm cutting acrylic at 60 power, I set the corner power to 59. I don't know if that actually helps or not but that is how they cut acrylic in the demo video I received with my laser. They set the corner power one less than the main power setting.

Try raising it above the cutting grid a little, that might help.

[VBLietuva]

Originally Posted by EXLASer Hi, Try to set corner power 40. And another way go to adjust the air assist a little on laser head, I don't know which kind compressor you use, if those doesn't work out, I suggest you to consider a professional compressor. Regards Mike mike@xyz-tech.com www.xyz-tech.com http://www.cnczone.com/forums/attach...1&d=1263018580

My laser came with basic air pomp and has no adjusting. Is there any way to adjust it? I tried to stick half of the hole that brigs air to a laser head, but it's not easy to do and I thing the same air amount comes. I tried to turn the air asist off even, but same problem. And you know, how I could know that with profesional air pomp ( You think I need more air pressure? ) that cost money I'll get what I want ? Today I''ll try to do some more testings with power and speed and so on. I'll let you know how was it Thank you all for your time

[Litografa]

Did you try 3M Citrus cleaner?

[notexpert]

Hi VBLietuva,

I have Rabbit laser HX4060-S, with optionally 60W tube. I made some tests
with cutting white acryl. Attached you will find a few photos of the cuttings.
In this case my settings was; power 40% - speed 9% - corner power 30%.
I was testing also with several different settings but in any case couldn't
get the results as shown in your photo. There was some small spots of dust
after cutting, but I wiped those off using 3M-citrus cleaner ( purchased from
Litografa - thanks ! ). Your problem could cause by the driver, so my advise
is just to try to install the driver again... ( this is my opinion - here on this
forum is a lot of people who knows these machines 1000 times better than
me ) But I have had some troubles also with my engravings and after
reinstalling the driver I notised that many of those was solved...

Good luck,
- Hannu

[KPBadger]

Hi All

i have noticed that the white acrylic seemsto be more sensitive to heat than the other colours. i have managed to set it on fire on one occasion when doing detailed cutting!

I use a product called "Brasso" which is household metal polish to remove staining with a soft cloth. its good stuff to have if you are working with acrylic. it will dull the surface of clear acrylic though!


regards

KpBadger

[simplify sandy]

My white acrylic always gets black burn along cuts - even worse when air assist is used. I mask the surface area before cutting. Best tape is TRANSFER RITE ULTRA medium tac. Be sure not to have air bubbles or the adhesive will scorch a light brown spot on acry. This mask can remain on the acry for up to 1 year & still have clean removal. I set it for 1 pass cut thru.
GOOD LUCK

Originally Posted by VBLietuva Hi all I have a problem cutting white acrylic with 60w laser engraver. When cutting the laser leaves black burns on the side of acrylic( picture attached) I tried : 1. Cut by 2 times with less speed or power 2. I tried to set corner power 0, 50 and 100, but not much help from that too 3. The acrylic should be good qualitty too, because I tried few tipes, but same problem I almost lost my hope... I bought this laser to cut acrylic mostly, and white, cream acrylic should be one of my favorites... Please help me with advices, what could be a problem with white acrylic Attachment 97064

[KPBadger]

Hi all.

Just a thought- might there be inconsistency in acrylic from various manufacturers? Or different variations on the polymer known generally as 'acrylic' but that might be chemically different from Perspex TM ?


i have found the white to be a bit sensitive to smoke staining on the surface but it should definitely not get black burn marks. certainly the cut should be clean.


Does your material have a manufacturers name on the protective film?
Maybe try sheet from a different supplier to see if that makes any difference.


The last white material i had was by "Repsol" and it cuts just fine.
(though it caught fire once! )


Cheers
KPB

[Litografa]

KPBadger - the current problem on market here in Baltic countries is that due crisis you can't find good choice of quality materials at acceptable price. Closed circle - crisis - less money - less spending for signs/advertising - smaller orders from manufacturers - bigger transport expenses - end user price became higher. So in crisis time price became even higher for quality materials. In this situation more peoples look on cheaper Chinese materials.
Speak about quality of Chinese acryl is very problematic. Just example. One of my customer have got big order for promo items from beer company. As usual negotiations were long and hard, so customer start looking for materials to fit price. Suddenly find perfect acrylic sheets in China at perfect price, buy them, deliver and start production. Material LOOKS LIKE REAL ACRYLIC, but when he start cut it with laser, he immediatelly understood that this material CONTAIN PVC as after first day all metal parts on laser were coverd with rust

[tomas1]

Originally Posted by VBLietuva Hi all I have a problem cutting white acrylic with 60w laser engraver. When cutting the laser leaves black burns on the side of acrylic( picture attached) I tried : 1. Cut by 2 times with less speed or power 2. I tried to set corner power 0, 50 and 100, but not much help from that too 3. The acrylic should be good qualitty too, because I tried few tipes, but same problem I almost lost my hope... I bought this laser to cut acrylic mostly, and white, cream acrylic should be one of my favorites... Please help me with advices, what could be a problem with white acrylic Attachment 97064

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