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James Wright
03-27-2008, 8:55 AM
Could someone explain Frequency settings for an Epilog for me...I have a Mini 24-45 watt....I usually leave it at 500....should I be using Frequency Automatic?....and what does the frequency do? I am trying to cut 1/4 inch Hard Maple...which is really dense...and I had to put the speed down to 3 for it to finally cut through..and getting allot of burning....is the frequency somehow involved ?

Any help would be appreciated....Thanks

Joe Pelonio
03-27-2008, 9:20 AM
The laser does not fire constantly. The frequency is the number of times it fires, or pulses. If you are cutting paper at low power and set it to 50-100 you will perforate it, rather than cutting it. With wood, a lower frequency will need more power and slower speed to cut through, but you will have less scorching/flaming. With a good air assist you should be able to jump it up to about 2500 or even 5000 and get a nice smooth cut with just a little charring.

George M. Perzel
03-27-2008, 9:21 AM
Hi James;
If you do a quick search on this forum you will find a number of well written explanations- check one of the ones by Rodne Gold- excellent.
Best regards;
George
LaserArts

Peck Sidara
03-27-2008, 10:18 AM
James,

Taken from our manual, available to download from http://www.epiloglaser.com/laser_manuals.htm


Frequency
Frequency is the number of laser pulses that the laser fires per inch of travel and is
set in the print driver and can be adjusted from 10 to 5000 pulses per inch. A
lower frequency number will have the effect of less heat applied to the material
being cut. Lower frequency rates are helpful for products like wood where
charring is evident at higher frequencies. High frequencies are useful on material
like acrylic where a large amount of heat is desirable to melt, or “flame polish”,
the edges.
Very low frequencies will produce a perforation, as opposed to a continuous cut.


Frequency Automatic

The laser frequency, or “pulsing”, can be manually set or set to

Frequency Automatic. When Frequency Automatic is set to Yes, the engraver’s software will automatically adjust the pulsing of the laser to a value of 5000. If FrequencyAutomatic is set to No you can control the pulsing of the laser in the Frequency box. Suggested frequencies are included in the tables showing suggested Speed and Power settings. The frequency range is 1 to 5000. Setting the frequency at a low value (50 to 100) will produce a perforation. Midrange values are use to reduce over burn when cutting, and high values are often used when more heat is desired to melt the sides when cutting acrylic.
__________________________________________________ ____________
For wood or materials that are likely to char/burn use lower frequencies like 4-6 hundred. I like to use 500 on wood. For materials like acrylic/plastics where you're looking for a nice clean flame polished edge, use higher frequencies 3500 to 5K.


Your difficulty with 1/4 hard maple is not likely caused by the frequency setting which you've chosen (I recommend 4-5 hundred), but rather a limit of power/speed. By the time you slow the machine down enough to cut thru completely, the speed/dwell time is causing the burning/charring.


My only suggestion is to try maximum air-pressure from your air-assist (if variable). It's my estimation that you could go as high as 40-45PSI of air.


HTH,

Dan Hintz
03-27-2008, 11:49 AM
Also consider higher speed but multiple passes... if charring is a major concern, don't dwell in one spot too long, just come back to it a few times.

Peck Sidara
03-27-2008, 12:48 PM
That's a good point Dan. Multiple passes at a higher rate of speed will prevent the charring/burning but the overall edge quality may not be what you're looking for.

Give it a shot, you may like what you get.

Eric Allen
03-28-2008, 3:22 AM
I've gone as low as 300 ppi cutting woods in single pass, seemed to help a lot. I usually have to slow it down a bit, around 5-7% below the listed speed. Since your machine is listed at 10 speed for that thickness, you might have to bump down to 5-7 speed range. The speed difference starts becoming more dramatic on the low end so you have to be careful.

Martin Reynolds
03-28-2008, 9:19 PM
There's a trick with these sealed lasers. They actually have a continuous mode, and a pulsed mode. When you set frequency, you are in pulsed mode. My tests indicate that pulsed mode gives you about 70% output power on my Explorer II (Synrad 30W). In continuous mode, the laser is always on and cuts with more power, but there's no way to control the laser power so you have problems with mixed curves and lines.