For some time now I've wondered if there was a way to use a CNC and end mills on foam inserts. Haven't really gotten into getting samples so I don't have experience with different types of foam. I started with Kaizen foam by Fastcap because I can get it from the local Woodcraft.
Challenge #1 - how the heck do you hold it in the view?! It's foam and a machinist vise is...well, designed for something of more substance. I was taking some measurements when I had an idea. What if I cut it while in the systainer base? I did a little test cut and found it held the foam quite nicely once cut to fit.
I used an up cutting 1/2-inch 2 flute end mill and ran the mill at max (safe) RPM - 3300. The foam does "move" out of the way as the end mill moves but it still cots quite nicely. The surface part of the cut moves out of the way so cleanup with a razor will be necessary however the bottom is perfectly awesome flat.
After playing with it I found that adding 3/16-inch to the desired dimension resulted in nearly a perfect fit.
I think what I like the most is the perfectly smooth bottom of the cutouts and the dimensionally perfect measurements of the cutouts. I tried to clean up the surface imperfections left by the process and found it less than easy.
My assumption is that if I were t find a foam that had a tighter cell construction, it may result in a much cleaner cut. If I could get my hands on an end mil with a more aggressive cutting angle it would probably make a cleaner surface cut.
I'm curious if the higher RPM of a CNC router or if an end mill with a sharper profile would leave a cleaner finish.
For those interests, it seems that it works. Pictures I've seen of others using a razor/blade seem to have sharper edges but I'm certain that my cuts are more perfect otherwise.
I'm on the fence if I'll mess with the mill and foam going forward. I have a few samples of other types of foam on the way. Hopefully one is the is more conducive to machining.
Challenge #1 - how the heck do you hold it in the view?! It's foam and a machinist vise is...well, designed for something of more substance. I was taking some measurements when I had an idea. What if I cut it while in the systainer base? I did a little test cut and found it held the foam quite nicely once cut to fit.
I used an up cutting 1/2-inch 2 flute end mill and ran the mill at max (safe) RPM - 3300. The foam does "move" out of the way as the end mill moves but it still cots quite nicely. The surface part of the cut moves out of the way so cleanup with a razor will be necessary however the bottom is perfectly awesome flat.
After playing with it I found that adding 3/16-inch to the desired dimension resulted in nearly a perfect fit.
I think what I like the most is the perfectly smooth bottom of the cutouts and the dimensionally perfect measurements of the cutouts. I tried to clean up the surface imperfections left by the process and found it less than easy.
My assumption is that if I were t find a foam that had a tighter cell construction, it may result in a much cleaner cut. If I could get my hands on an end mil with a more aggressive cutting angle it would probably make a cleaner surface cut.
I'm curious if the higher RPM of a CNC router or if an end mill with a sharper profile would leave a cleaner finish.
For those interests, it seems that it works. Pictures I've seen of others using a razor/blade seem to have sharper edges but I'm certain that my cuts are more perfect otherwise.
I'm on the fence if I'll mess with the mill and foam going forward. I have a few samples of other types of foam on the way. Hopefully one is the is more conducive to machining.
