Just purchased a CrossFire XR and getting it put together now.
We have SolidWorks CAD for creating my geometry. (I think I am comfortable on the CAD portion.) i understand I just need to create a 2D DXF file for the CAM program.
My boss is getting SheetCAM for generating the tool path. The Langmuir site says they have guides for the CAM portion, but I only find a guide for the Fusion 360, not the SheetCAM. If someone could point me toward a guide on SheetCAM, I would be most grateful.
I have zero experience in CAM setup, however, flipping through the forums and guides I have been able to find, I understand I need some basic information:
A) Clearance diameter. I believe this is the diameter of the cutting head assembly. I measure this at about 32 mm. Correct?
B) Kerf Width. This is the width of material removed while cutting and is dependent on the nozzle installed. Correct?
C) Lead-in radius. Not certain what this means, but it seems from a few posts like I should be using approx 1.5 mm. Correct?
D) Lead-out radius. Not certain about this either, but somewhere it said this should be zero. Correct?
E) Cut Speed. This is based on the machine, the material, and the thickness. However, I’m not sure how to go from that to a cut speed. Is there a table or formula somewhere that I’m not finding?
Any other advice you can give? Is there something that most of us noobs screw up? Any more recommended utube videos for beginners?
Ok, this sounds even to me like a stupid question.
Some of the videos show a ‘backing’ material under the actual material to be cut. Some do not. What is the purpose of this and how do I tell when I need a ‘backing’ material?
In a write up.
“…For the purposes of this example our material is a 300mm x 200mm sheet of 6mm plastic that is clamped to the table with it’s bottom left hand corner at X=50mm,Y=50mm. The sheet is clamped on to a piece of 0.25in board to allow the cutter to cut right through without damaging the table. …”
There was also a video that I can’t re-find that had a backing material. I think that one was also artwork on a sheet of plastic. Is it maybe just a thing for plastic?
You might have that correct but I don’t use SheetCAM.
Your definition is correct. An accurate way to measure is cut out a set dimension, say 24 mm x 24 mm. Measure the hole left in the metal. Subtract 24 mm then divide by 2. That will be the kerf for that thickness metal at the amperage used.
That is the radius of the cutting path that is allowing the torch to get up to speed and full plasma burn before it starts to cutting metal that is adjacent to your actual part.
This varies and different users have different approaches that work for them. If you have room on your part, it could be the same as the “lead-in”. Some use no lead out as we suggest. Others use a very small finishing “overlap.”
Your machine may have some table to give you a starting point. It simplest to keep the amperage the same and vary you cut speed. Test cutting should be done to dial in the best cutting results. Too fast and you will get poor penetration and/topside dross. Too slow and you will get bottom side dross with too much material blown away. And yes, you always need to go slower the thicker the metal.
(Note: I believe you added more to your original post than when I first replied. )
And, I don’t know what you are referring to with the backer board. Perhaps that is someone that doesn’t have a water table/bed.
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