Also, I think those recommendations are based upon someone moving the router by hand and not a machine… the feed rate of a person is probably much higher than 8mm/s. Feed rate and RPM are proportional… faster the feed rate, faster the RPM.
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If you’re making powder, you are cooking it. It’s just not showing yet.
I would not lose any sleep about making powder though. Chips are better, buy it’s not the end of the world.
I make a lot of powder on my MPCNC…
Thanks for all the educational replies…I appreciate it. I’m always looking to learn. Indeed, learning new stuff is one of my favorites activities, and a big part of the fun of the CNC for me.
FWIW, I don’t know that I have been making powder. The 1/4" bit I was using last night has been making tiny slivers. I guess I’d call those chips… They are amazingly consistent little slivers. I’ll have to look more closely at what the 1/8" bits have been making.
I certainly won’t be losing any sleep… based on last nights experience, I think I’ll continue to trust my senses more than anything else, but I’ll know to watch for powder ,as well, in the future. It was interesting to note that I could smell the cooked wood almost immediately…probably within 30 seconds of the start of the cut. I would have thought the dust collector would have drawn the odor away…
The part I was cutting last night has a bunch of 1/2" wide slots for a “tab and slot” type assembly. Using an 1/8" bit would leave a 1/4" thick bit of wood in the middle when cutting, so I chose to use the 1/4" bit and turn it all to sawdust (or chips/slivers 8^) rather than leave those pieces “floating” in the holes. Probably wouldn’t be a problem, but I’d like to hear what others might recommend…
Sorry to @kd2018 for usurping your thread…, but it is all relevant to the “Milling Basics” topic.
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No need. It’s full of good information. I’m just glad I didn’t screw it up myself by accidentally spiraling it off into a tangent about other machines.
What doc and feed rate? I got some burning at 2 in poplar yesterday.
The best way to figure this out on your machine is to try it. You can not really ask someone what they are using, it may or may not be possible on your machine.
Pick a small test file that only takes a few minutes that includes slotting, pocketing, and a plung or two. The try it.
My basics have 1mm DOC at 8mm/s…that works without burning but it should be on the lowest for load on every machine. So my machine works at those numbers but also works at 9.5mmDOC and 10mm/s.
In wood you have a giant variety of options, trust me, just try it out. There is nothing anyone can say that will be better than a test cut or 20. As you get into plastics, and then metal that window for what works is very very small. So learn in wood, learn to know what a good cut sounds and looks like, then go from there.
Oh and don’t forget about knots…things that work in nice wood will not work across a knot. So unfortunately most of the time you have to use speeds that accommodate that just in case.
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I’ve been playing around with linuxcnc’s flavor of gcode. It’s pretty cool in that the gcode itself can use parameters/variables, do math, loops, etc. It’ll be good practice to make a generic test file for this purpose.
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