I am trying to cut 3/16 Chemcast GP Acrylic on a OMAX 55100, The material has a protective paper on both sides. The part that I am trying to cut is a Logo that wont allow me to pierce away from the cut and lead in (not enough room).
The Pierce is what is fouling up the part.
I have tried changing several of the settings on the machine with not much luck.
Also guessing at the machineability value since it does not come pre-loaded for this particular material.
Any help would be greatly appreciated.
Thanks...
TFabian said
May 12, 2012
So is the edge quality good, except where you are blowing out material on the pierce?
InspInd said
May 17, 2012
try putting a thin piece of aluminum sheet metal over where it will pierce. The aluminum will absorb the impact of the pierce and may not shatter of blow out which is what sounds like is happening. I just tape it on with red stucco tape, or you can just put one piece over the entire plastic.
Bdubb said
May 17, 2012
Did you figure out how to pierce and complete it?
smokeand mirrors said
Mar 2, 2013
PRE-DRILL Lead in's and outs conventionally
Jtorva said
Mar 5, 2013
There are a number of things that you can try. I am guessing that you are getting chipping and cracking where you pierce the acrylic. I have run into this problem a lot with cutting acrylic.
If you do not wish to pre drill the pierces I would recommend the following.
An Item that omax sells that makes this process a lot less of a headache is the pull to open valve. The typical on/off valve on the nozzle requires the water pressure to push the needle out of the hole to open the nozzle. The problem with this is that pressure builds up behind the nozzle and then blasts the material you are trying to cut. With a Pull to Open, air is used to pull the needle out to allow the water to flow through the nozzle. Now with the pull to open you can go into your machines settings and tell the nozzle to open with zero delay. In order to gain the benefits of this, in your change path setup make sure the very brittle check box is checked. This will turn the pump off during your traverses. Now with the zero delay the nozzle will open right when the pump starts back up which gives you a softer pierce since you don't have full pressure being that be pump takes an x amount of time to reach the set rpm.
Also make sure you are using low pressure piercing. Another thing to try is to reduce your abrasive flow rate. I haven't played with this yet but a couple of guys at omax recommended I try it out. For example on glass they recommended an abrasive flow rate of around 0.4 lbs per minute. The standard setup on an Omax machine with a 0.014" orfice and 0.030" mixing tube is 0.75 lbs per minute. I figure using this technique on acrylic will have some benefits as there will be less media impacting the acrylic when a pierce occurs.
I am trying to cut 3/16 Chemcast GP Acrylic on a OMAX 55100, The material has a protective paper on both sides. The part that I am trying to cut is a Logo that wont allow me to pierce away from the cut and lead in (not enough room).
The Pierce is what is fouling up the part.
I have tried changing several of the settings on the machine with not much luck.
Also guessing at the machineability value since it does not come pre-loaded for this particular material.
Any help would be greatly appreciated.
Thanks...
PRE-DRILL Lead in's and outs conventionally
If you do not wish to pre drill the pierces I would recommend the following.
An Item that omax sells that makes this process a lot less of a headache is the pull to open valve. The typical on/off valve on the nozzle requires the water pressure to push the needle out of the hole to open the nozzle. The problem with this is that pressure builds up behind the nozzle and then blasts the material you are trying to cut. With a Pull to Open, air is used to pull the needle out to allow the water to flow through the nozzle. Now with the pull to open you can go into your machines settings and tell the nozzle to open with zero delay. In order to gain the benefits of this, in your change path setup make sure the very brittle check box is checked. This will turn the pump off during your traverses. Now with the zero delay the nozzle will open right when the pump starts back up which gives you a softer pierce since you don't have full pressure being that be pump takes an x amount of time to reach the set rpm.
Also make sure you are using low pressure piercing. Another thing to try is to reduce your abrasive flow rate. I haven't played with this yet but a couple of guys at omax recommended I try it out. For example on glass they recommended an abrasive flow rate of around 0.4 lbs per minute. The standard setup on an Omax machine with a 0.014" orfice and 0.030" mixing tube is 0.75 lbs per minute. I figure using this technique on acrylic will have some benefits as there will be less media impacting the acrylic when a pierce occurs.
Give it a go and report back your results.
Jordan
http://www.karice.net/