Very Detailed Designs and Acrylic

[Ed Maloney]

I've been having a problem with flaming up of detailed designs when I am cutting acrylic. It's one of those designs that the laser hangs around a general spot (1/4" or so) for maybe 10 seconds.

I cleaned the honeycomb grid and the lenses. Bed is flat. Anyone else having these problems?

Ed

[Frank Corker]

Increase your speed or reduce your power. Instead of using 100% power knock it down to 75% or 80% it's surprising how much material it will travel through even on lower power setting. Reduce your speed also helps and check your air assist nozzle to make sure there is some air coming through. I have one of the small gast type compressors and they have this ridiculous little gauze airfilter which corroded and blocked, result no air assist. Oddly enough it took me a while to realise it because I could hear the pump running and thought nothing of it.

[dave cox]

With the ULS driver and I think Epilog reduce the number of nodes as well wet brown paper underneath the acrylic also as fast and little power as possible will help.

[Chuck Stone]

reduce the number of nodes

that's my bet, from the description.

[Ed Maloney]

Dave - Good point about the nodes, I forgot about that. I checked the artwork and there were minimal nodes for the design.

Frank - I have been working with my laser for over 6 years now and have only followed the Epilog suggested settings for the various materials. I have adjusted the speed in some cases, but only about 5% more. So for the 3mm acrylic I was using 15S/100P. I would have to experiment, but do you think 15 is too slow?

[Frank Corker]

No 15 is not slow even on a 45w it's about the right power. If it is hanging it has to be a hidden node in the artwork or it doubles back over exact lines making it hard to spot. Perhaps you might post the offending section and let us have a look and see if we can spot something for you. If it's sensitive and not for posting, perhaps pm and send to someone by email.

[Ed Maloney]

Thanks Frank - Here it is.

Ed

[Mike Null]

The problem is your drawing. Look at the nodes. There are too many everyplace. Do you really want to use cmyk colors?

I suggest re-drawing all of it.

[Ed Maloney]

Mike - Funny I didn't notice the CMYK colors.

When I look at the drawing (as curves) I see nodes in appropriate places. But - If do a convert curves to object I see many more. So what I see (as curves) is not what is actually sent to the laser?

As a side note the design was from the Creek years ago, just in case someone else picked it up.

[Ronald Erickson]

I'm out of 1/8 acrylic, so I cut it into 1/4" acrylic with a paper mask. I had no issues with the number of nodes or the quality of the cut. Eleven nodes on the more decorative branch created no issues. (The only time I had an issue with nodes was when I was cutting an outline of the State of MN and the outline had a few thousand nodes; that created scorching on the 1/4 MDF Plywood I was cutting.)

There was one very minor flare (just a quick spot of flame) at the very beginning of the cut, but it didn't even brown the paper mask. I did change the cut order so the hole would cut first. BTW, I'm using CorelDRAW X6.

Unfortunately I don't know how my settings would translate to your laser. My settings won't help you, but I'll list them anyway.

The settings I used on a Trotec Speedy 300 (for 1/4 inch acrylic):
Engrave: 80 power, 55.00 speed, 600 PPI, Air Assist ON
CUT: 80 power, .30 speed, 9000 Hz, Air Assist ON

The settings I would have used on 1/8 inch acrylic (if I had some) are:
Engrave: 80 power, 55.00 speed, 600 PPI, Air Assist ON
CUT: 50 power, .65 speed, 9000 Hz, Air Assist ON

50 power (1/2 power on an 80 watt laser) would be 40 watts, but the speed ratings don't line up at all. A speed of .65 on the Trotec seems plenty fast and I very rarely cut anything above a speed of 1.0.

248073

[Real Mercier]

Try this. I think the problem is your snowflake is made of all separate lines with each line having a separate start and end node. I selected all the snowflake lines and joined them. That makes them one continuous line and should cut better. Let us know how it came out.

Real Mercier

[dave cox]

Try locking the hole and raster area and select all the rest then arrange>combine and convert to rgb that may help.

[Ed Maloney]

Thanks again!

Real - I'll check out your version. Much appreciated and Dave thanks for the tip.

Here's an interesting thing. I just did some tests and have the speed up to 20 for the 3mm which is very close to the speed I use for 1.5mm. It was a simple square shape, but it cut out just fine. I replaced my 35W tube about 18 months ago. I wonder if they sent me a hot one this time?