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Rob Preston
01-24-2015, 10:43 AM
Any ideas appreciated guys ?
Trying to cut 3mm MDF but all it is doing is leaving a thick line and not cutting right through ? i am using RDWORKS8.0 software but having no joy

thanks

Roy Nielsen
01-24-2015, 10:46 AM
A thick line first leads me to thinking that you are out of focus. Try raising or lowering your bed.

Rob Preston
01-24-2015, 10:51 AM
Thank you Roy, i have tried raising and lowering but no joy. Any ideas on what settings i could use ?

Richard Rumancik
01-24-2015, 11:49 AM
My first thought was the same Roy's - something seems wrong with the optics. Your experiment suggests it is not a focus problem. But if you are getting a wide line I have my doubts that a different power/speed setting is going to cure this.

I would suggest that you experiment until you can scribe a line that is only .006" wide or less (I don't know which lens you have installed.) Never mind about cutting through at the moment. (If you can't scribe a thin line you have to find out why.)

The other possibility I can think of is that the adhesive in the mdf just isn't laserable and you are just charring the material. In such a case you could get a wide char line. If you start at 90% power and drop the speed, you will find the best setting yourself pretty quickly. But it is possible that the material just isn't suitable for laser cutting.

Bill George
01-24-2015, 12:32 PM
Any ideas appreciated guys ?
Trying to cut 3mm MDF but all it is doing is leaving a thick line and not cutting right through ? i am using RDWORKS8.0 software but having no joy
thanks

Maybe you posted but I missed, your machine ? and its a CO2 laser with how much power available? Is it Vector cutting for sure or is it trying to Engrave the line? Are you able to Cut other materials?

Rob Preston
01-24-2015, 12:51 PM
Thank you Richard and Bill, it will not cut anything I have tried Mdf and Ash ? It is the Pro Co2 from eBay. Not sure Bill about vector or engrave the line , can you select which one you want on the software ? I am able to engrave onto any material but just can't cut ?

Thank you

Wilbur Harris
01-24-2015, 1:11 PM
Not familiar at all with the software you're using but - yes. Figure out how to tell the software to cut (color a line or something) and set the cut power/speed to whatever will get through the material. Somebody else will need to tell you how to do that but I think that's the ticket.

Have you cut material before this problem?

Bill George
01-24-2015, 1:13 PM
Thank you Richard and Bill, it will not cut anything I have tried Mdf and Ash ? It is the Pro Co2 from eBay. Not sure Bill about vector or engrave the line , can you select which one you want on the software ? I am able to engrave onto any material but just can't cut ?

Thank you

Once again, how much power or wattage is the machine rated for? There a at least a couple hundred or more eBay sold Chinese lasers. Do some searching on here to read up about engraving vs cutting or Vector cutting. Lots to learn.

Bert Kemp
01-24-2015, 1:14 PM
how many watts tube can we get a screen shot of your software settings


Thank you Richard and Bill, it will not cut anything I have tried Mdf and Ash ? It is the Pro Co2 from eBay. Not sure Bill about vector or engrave the line , can you select which one you want on the software ? I am able to engrave onto any material but just can't cut ?

Thank you

Rob Preston
01-24-2015, 1:20 PM
This is the link to the machine here :
http://www.ebay.co.uk/itm/PRO-CO2-ENGRAVER-CUTTER-LASER-ENGRAVING-MACHINE-AUXILIARY-ROTARY-DEVICE-50W-NEW-/331249860707?pt=LH_DefaultDomain_3&hash=item4d2007c063
I have not cut anything so far as it just wont go right through the wood ?

Bert Kemp
01-24-2015, 1:23 PM
50 watt should have no problem cutting upto 1/4 mdf , ply , ash ect ect we need to find the focus point and the right cut setting need screen shot or someone familiar with your software

Bert Kemp
01-24-2015, 1:27 PM
look at this manual http://nuke.astrolabi.com/Portals/0/Laser/User%C3%86s%20Manual%20of%20Laser%202Engraving%20C utting%20Software%202.pdf

Bill George
01-24-2015, 1:54 PM
50 watt should have no problem cutting upto 1/4 mdf , ply , ash ect ect we need to find the focus point and the right cut setting need screen shot or someone familiar with your software

Bert he does not know the difference between cutting (vector) or engraving (raster) . He needs to understand which is which before he can decide on what the correct focus should be. I agree he should have no problems vector cutting any of the above with his 50 watt machine. Assuming the mirrors and lens are correctly aligned.

Jerome Stanek
01-24-2015, 2:29 PM
First is there a lens in it and what focal length is it? He says that it is giving him a big spot and not cutting so I would check the lens.

Bert Kemp
01-24-2015, 4:38 PM
Bill maybe I don't understand how a laser focus's I was under the impression that the focal distance is the same for both raster and vector. Maybe I been doing this all wrong but I use the same gauge and focus at the same distance no matter what I'm doing.


Bert he does not know the difference between cutting (vector) or engraving (raster) . He needs to understand which is which before he can decide on what the correct focus should be. I agree he should have no problems vector cutting any of the above with his 50 watt machine. Assuming the mirrors and lens are correctly aligned.

Rob Preston
01-25-2015, 9:41 AM
305045
Here is the screenshot.

Rob Preston
01-25-2015, 10:16 AM
Also; just removed the lens from the laser, and it appears it has been burnt, would this be the source of the issue?

305046

Chris Corwin
01-25-2015, 10:24 AM
Yes that's a good place to start. Dirty optics make for big lines. I try to clean my optics more often when I notice a lot of smoke being generated.

Rob Preston
01-25-2015, 10:36 AM
i have only had the laser for over a week , surely it should not be like this ?

Chris Corwin
01-25-2015, 10:52 AM
i have only had the laser for over a week , surely it should not be like this ?

Sometimes I clean my optics multiple times a day depending on what I cut.

It looks like a cheap lens. I try and stick with the higher quality stuff. Usually a higher quality lense costs me about $50 as opposed to the $24 cheapies I have seen.

You can tell the difference between a good quality lens by its translucency. Cheap ones are cloudy and good ones are relatively transparent.

Bill George
01-25-2015, 12:11 PM
Also; just removed the lens from the laser, and it appears it has been burnt, would this be the source of the issue?

305046

Rob, did you have your air assist on? I would try to clean with DNA or Windex and if it comes out clean re-install. It will need replaced sooner or later. You need to do a Search on here on how to check your optics and mirror alignment. Mine was off when received and you need to check and learn how to align the mirrors. Could be nothing wrong except that.
To do a quick check for Vector cutting create a box in your laser control software, pick or select and in the Layers menu Set as Cutting, then power and speed. Just to make sure it cuts your MDF, set the Power pretty high like at 90% and Speed at say 20 mm/Sec that will be over kill but your just proving it Can do it.

Bert Kemp
01-25-2015, 12:20 PM
Rob
This could be the problem, clean the lens, then clean your mirrors, check your alignment, then try cutting again. Make sure your air assist is on. I have my Air, Water pump and exhaust fan all on a separate Surge protected UPS. The machine will not run if I don't hit the switch to turn them all on

Rob Preston
01-25-2015, 12:46 PM
Thanks for all the replys
i have tried cleaning the lens with meth spirit but nothing is coming off it ? looks like i will have to buy a new one, will the mirrors be ruined aswell?

Jerome Stanek
01-25-2015, 1:05 PM
I wonder if the lens had crud on them from shipping.

Bert Kemp
01-25-2015, 2:20 PM
If the mirrors look dirty take some DNA on the end of a cotton swab and gently clean them, an alignment might be necessary after cleaning the mirrors . Do you know how to align the mirrors?

Rob Preston
01-25-2015, 4:28 PM
Thank you Bert, I have cleaned the mirrors using methylated spirit and done an alignment . Don't know what's next , looks like I will have to buy a new lens

Jerome Stanek
01-25-2015, 4:36 PM
Try scrubbing the lens maybe you can get most of that off. You can't hurt it anymore than it is now

Bill George
01-25-2015, 5:40 PM
DNA is de-natured alcohol, takes about anything off, acetone might work also. To replace you need to know the focal length of the lens and the diameter. They have them on eBay.

Rob Preston
01-25-2015, 5:43 PM
Thank you bill
how do you know what the focal length is , any way of explaining ?

Bert Kemp
01-25-2015, 5:46 PM
Rob just get a 2 or 2.5 inch focal lens you can measure the dia with a ruler. calibers would be better.

Bert Kemp
01-25-2015, 5:51 PM
Junior Just buy a 2" or 2.5" focal length lens, measure the Dia with a ruler or calibers if you have them , 2 2.5 is a good all around lens,

John Noell
01-25-2015, 6:21 PM
Rob, there are two modes, vector (for cutting - where the laser follows a line) and engraving (called "scan" in your software - where the laser goes back and forth like an inkjet printer). For either mode to be effective, your laser beam needs to be carefully aligned so it hits the center of the mirrors and the center of the focusing lens. You must keep the lens a pretty exact distance above the material you are cutting or engraving so the beam stays in focus. If you do not have a guide to show you the proper distance, there are posts here that show you how to determine the correct distance, so you can make a guide for yourself.

Ray Scott
01-26-2015, 11:06 PM
I recommend a 50.8mm lens or 63.5mm lens. Go for the premium quality version. It will cost more.. Buy from a reputable seller.

The lens could have been damaged by you. The lens often has some oil on it .., If it was already installed when shipped direct from China. Cold temperature optics and hot air can cause humidity to condense onto the lens.

If you aren't adept to laser machines, it is a good idea to try and keep your eyes open for anything that could go wrong.

thank you,