As part of a non-robotics-related project I have been looking at using a part made from a carbon fiber or mixed carbon fiber/kevlar composite sheet. The part in question would be circular or elliptical in shape and be about 2mm thick. Is it possible to use a laser or water jet to cut such a part?
We’ve cut thicker than 2mm carbon fiber before on a waterjet, its definitely possible that way. I thought I’ve heard about bad fumes from carbon fiber on laser cutters, though I’m not sure about that one.
I have a fair amount of experience with waterjetting carbon fiber. It’s definitely a good way to achieve the shape you want but be sure to purchase enough material to allow for some botched parts. Sometimes when the waterjet initially pierces the carbon fiber, instead of going straight through the part some of the water will get in between the layers of carbon fiber which can lead to the layers separating. Be sure to keep that in mind but otherwise, you should be good.
The one time I cut carbon fiber with the waterjet it was in 2015. It was an experiment and we didn’t count on it for actual use on the robot (but did end up using it after CMP).
I was cutting a plate using a polypropylene honeycomb core. Due to the same concerns addressed by borisf (the water running along the inner face of the lamination and damaging the core-to-carbon interface while piercing the bottom layer) I did not do any interior pierces/features. I only cut the perimeter. While cutting on the waterjet, I started the stream off material.
For interior features, we laser cut some acrylic sheet and used it as a template with center punches.
CNC router worked well for us for cutting 1/4" CF sheet with a wood core. We’ve also done foam core. Both worked well with the router. I can’t speak to using a laser or a waterjet on it.
Yes, Carbon Fiber will release Chlorine gas when cut with a laser cutter
:eek:
-Zach
Can you provide a reliable source for this? I suspect it’s possible that the epoxy could off gas chlorine but even that I’m not sure of. This doesn’t seem right to me but I could be wrong - I am far from an expert on this.
^^^
I’ve spent a good amount of time cutting carbon fiber and fiberglass sheets with a waterjet for some university projects. The reason that this happens is that the water pressure when the flow starts isn’t immediately enough to go all the way through the sheet, resulting in causing the layers to delaminate instead.
The solution that I’ve found to work best is (whenever possible) to have the cut begin off the edge of the sheet, and then move in to where you want the part to be. This way, the water is all the way up to pressure by the time it comes into contact with the sheet, and you get a nice clean cut without wasting any of the material. In cases where it’s not possible to do this (e.g. cutting holes in your part), you generally need to allow an inch or so in every direction for piercing damage. If that’s not possible because the hole is too small, I just leave that feature out and finish the job on a mill or drill press.
Feel free to pm me for other questions about waterjet usage techniques.
Luis