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Dave West
11-14-2007, 10:41 PM
I cut out a plexiglass ornament (extruded I think) today and was wondering about the poor edge quality. It's an old Epilog without air assist. My settings for the 1/16 material were 35 speed, 100 power with PPI at half (my rate range is 1-100). Belts seem tight but are probably worn. Any suggestions?

Thanks,

Dave

Shane Turner
11-15-2007, 12:12 AM
Could be the fact you have no air assist, but the edges do seem a little wobbly even for that.
Try cutting out a square to see if the wobble is confined to one axis only?

Rodne Gold
11-15-2007, 12:56 AM
The acrylic has suffered major heat stress and is being "overprocessed" , either cut down your PPI , power or add air assist.
Cutting pex without air assist is not good news cos it is way more prone to flaring and fires , there is no forced mechanism for the melt to be ejected out the bottom of the cut and the pex cut edge cannot be maintained at the correct temp and the melt resolidifies behind the cut and leads to striations , stress cracking , dros on the bottom edge and so forth.
Adding air asist to any laser cannot be hard , all you have to do is get a small compressor and a air control type valve and some aquarium tubing and make sure nothing fouls when the laser is traversing. Point the end of the tubing (or use some sort of tip) at where the beam hits the item.

Frank Corker
11-15-2007, 6:36 AM
I also think that is extruded acrylic, I don't find that it cuts as well as cast acrylic

Neal Schlee
11-15-2007, 1:50 PM
Dave, The older Epilog's do not vector cut well, especially the models with a moving table, this may be your problem.

Neal

Kim Vellore
11-15-2007, 2:19 PM
One more thing to note is make sure that there are not too many nodes in the drawing. Drawing a square and cutting it will make sure the drawing itself is not a problem,

Kim

Mike Mackenzie
11-15-2007, 4:08 PM
I would try to slow it down and see if that makes a difference if it does I would look into the motion system.

Sandra Force
11-15-2007, 6:03 PM
I am going to give conflicting advice. I cut my air down to minimal when cutting acrylic to get a glass edge. Very slow speed, high power for me equal good edge on 1/4" to 1/2" acrylic. This is with a 100w. I will agree on cutting back on the nodes if you can. Makes for cleaner edges. Try both ways and see which works best for you. I have found different types of laser react differently to air assist. Just be very carefull of FIRE!!!! :eek: