Depth and speed calculator?

I’ve been researching for days and all I got is more confusion.

I want to cut wallnut with a 0.5 inch, 2 flute straight bit.

I’m using the Makita 0701

I need to machine a fairly large amount of material (5x5x3cm aprox) , and I need to do many many parts like that.

I’m not sure what’s the best way to achieve faster jobs. Should I do shallow cuts and go fast ? or deep cuts and go slowly? How deep should I go?

I would appreciate some help pointing me in the right direction. Thanks!

Its all just math in the end.
Push your machine to the max. Test your recipes. and crank it up.
Go full DOC. Unless cleanup is required, then leave some stock.
Start at slow plunge/spiral then crank up.
Then work on ipm and see/hear/smell/feel how the machine is handling. Your senses are pretty good at feeling it out. I always get a prickle on my neck before an endmill snaps.
Dial down rpm up ipm and DO NOT EVER BABY THE BITS! Its called infanticide. No babying bits.

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What software (CAM) do you use?

Pockets 50x50mm and 30mm deep?

I’m using fusion 360 and you are right, 3 cm deep.

the shape is not a simple square, but close enough.

In F360 use 2D adaptive, this is a rough clearing strategy, follow up with a finishing pass (separate).
The key is to find your sweet spot for chip load (thickness/slice per flute) and from that compute feed (FR) and width of cut (WoC)

I dont have experience with 1/2" or walnut so can not suggest further :neutral_face:
But I have gone 9mm deep in aluminum with a 1/8" bit and Makita.

Walnut is pretty soft so you can cut faster than you would think.
I think shallower cuts done faster is the way to go.
The general starting point for most bits is a DoC (depth of cut) no greater than 1/2 the diameter. But a 1/2" bit takes a pretty big bite. So you may want to go shallower than that.

I have found that with my machine DoC seems to have a bigger impact on quality than feed rate.
So I have found that going a little shallower but faster seems to work ok. Especially for roughing operations.

Feed rate and RPM combine to determine how fast the bit is moving over the wood. If the bit is not moving fast enough it will recut the same spot over and over. This is called rubbing as the bit “rubs” against the same place, causing friction, causing heat. A little too much and you can char the wood. Way too much and you can heat damage the bit.

So you can slow your RPM (which is why most people cut at the lower router speeds) or increase the feed rate. I have found that at the higher feed rate if the Depth of cut is too deep you can get excessive load on the system, causing the bit to deflect. A little defection and your cut quality will be reduced. Too much deflection and things can bind, or slip, or get pulled off course.

So you can play with all three variables to tune things. As far as what ranges will work? A lot of that depends on the machined, the bit, the material, etc.

When I first started I was using G-Wizard to calculate my settings and it worked pretty well.
After I upgraded my machine a bit, I found that it was much more forgiving about what settings I used. Getting acceptable results over a wider range. (So I have gotten a bit lazy about it.)

Your best bet is to run a few test cuts in some scrap (pine would work for starters) just to get a feel for what the bit can do.


I’m glad to get this kind of empirical - listen to your heart answers :slight_smile: I thought there was a hard absolute truth somewhere that I was missing, and I was going crazy looking for it.

I will definitively be experimenting to see what works best and hopefully I can report back some useful info.

In your experience, how fast can I go with the Xcarve before it starts to become unreliable ? I see Easel presets don’t go past 812.8 mm/min but I’ve noticed Easel is generally super conservative with its presets.

Based on what I’ve seen in the forum, 1000 mm/min is probably safe ( Assuming I can find a sweet spot with the material) but ignoring the material completely, what’s the max feed rate you’ve used reliably?