I’ve got to cut some patterns out of 12" x 12" x 0.2" thick delrin plate. I have some small pockets that my 1/8" endmill is too big for so I’m going to need to use my 1/16" endmill. What advice do you have for speeds & feeds and depth of cut and rpm?
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I dunno. I keep going back and forth on this.
On the one hand, I’d really like to just populate every possibility at: https://www.shapeoko.com/wiki/index.php/Materials, on the other hand, I think CNC Cookbook’s G-Wizard is an excellent bit of software, and really appreciate the pricing model, but on the gripping hand, I’d really like there to be some industry-standard opensource solution in this space.
If you’ve got some spare endmills, my suggestion would be the test cutting technique from: http://www.precisebits.com/tutorials/calibrating_feeds_n_speeds.htm — then we can add those numbers to the first link above?
I still don’t understand why every person who purchases endmills has to enter all the data on them by hand — why isn’t there an industry-standard XML schema for defining an endmill’s geometry which can then be loaded into a given CAM program?
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I can definitely do some trial and error. I just don’t want to run the job too slow (taking forever) vs too fast (breaking a bit). 99% of the time I’m cutting with 1/8" and 1/4" bits and try to follow the published feeds and speeds for the Shaepoko and Nomad. Delrin’s pretty forgiving stuff. I can be aggressive with it. Still, 1/16" bit’s are new-ish territory for me.
…and yes, and endmill database that is standardized for most CAM packages would be a hell of a nice thing.
I run my .062 endmill at the following settings:
depth per pass: .400mm
stepover: .750mm
feed rate: 400mm
plunge rate:100mm
RPM: 10,000
This is for brass… For delrin, I would recommend keeping the depth and stepover, but increasing the feed rate. Fast light cuts will save you heartache, especially with a small end mill like this.
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Probably has to do with manufactuers protecting their “proprietary designs”, but an open source would only need to include the different bevels and such that create a cutting edge. We need an experienced engineer minded machinist who could list those different geometries so someone could help assimulate the data into something useful. Onsrud uses "proprietary design criteria because they list cutting data but do not show the geometry that causes their bits to cut different. At least that is what I have found as a non-machinist. Jude
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This is got to be the best tutorial on feeds and speeds for routers, ever!
I don’t want the XML file to have sufficient information to re-create an endmill, just enough to allow it to be used for CAM.
I’ve been trying in excel and easily see the extreme complexity of adding those data points . It is very difficult, if I can see any success with my excel file I’ll post it, but still experimenting. Thanks for your efforts, and by the way, back a while ago I posted my “Vote for Will” replies… How did the S"election" go? Did you get S"elected" ? Maybe we need a King??? Jude