Hi people! I am going to cut 3/4” walnut soon and I’m wondering if there’s anything I should know before going in? I was under the impression walnut is really hard and I wasn’t sure if I should do anything with my feeds and speeds vs just going with general hardwood settings.
I just keep the chip thickness between 0.001 & 0.002 and depth of cut at 1/2 bit diameter and generally have no problems. Carefully ordered cuts may be needed to reduce chipping on outside corners, but thats been my experience with any hardwood.
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Griff
(Well crap, my hypometric precursor device is blown…)
4
It’d be helpful to know a bit about your project. Something highly detailed requiring 1/8” or smaller end mills? Or a sign needing a lot of hogging out?
I cut a lot of white oak Janka hardness 1360. Black walnut is 1010 by comparison.
If I’m hogging out a serving tray I’d use a 3/8” single flute at full depth of cut (1.5”), .125” width of cut, 100 ipm. This is on an XL w/2.2 kw spindle. Adaptive tool path.
If I’m cutting insets for letters, numbers etc I might use a 1mm 2 flute, 2mm depth of cut, .5mm width of cut, 1000mm/min.
So, depends on your project. Sorry for imperial/metric mix, personal problem, tend to think imperial for large, metric for small.
I’ve attached a screenshot of the artwork. I’m actually going to use a piece of 1/2 inch walnut instead of 3/4" and there is an outside contour cut I want to cut all the way to stock bottom. Then the interior artwork will be a vcarve/pocket combo at 1/8 inch depth. I’ve attached a screenshot of the artwork.
I love Walnut and it machines beautifully. It isn’t very hard, as hardwoods go. I usually use the feeds and speeds suggested by Carbide Create, and up to .08" to .10" depth of cut (with a 1/4" endmill). Downcut endmills do an excellent job of preventing chipping.
Walnut does machine well and is not nearly as hard as oak. You could be conservative and increase rates on the fly. I love to make boxes with walnut and maple. Walnut being dark does not show fine detail as well as lighter woods. The walnut takes detail fine but is hard to see.