Good grief 10ipm is boring

seems to be about the only speed my 1/4" bit doesnt rattle itself to death. gonna be here all night

Must be metal?

nope its pine. it just tears big chunks of wood off and chatters really bad at anything faster. i dont know if the bit is crap or what. so frustrated with this thing

What kind of bit and how sharp is it?

Spiral upcut 2 flute 1/4 bit not sure how sharp

Ive just tried a much faster speed (worked my way up to 80ipm) but only taking 0.025 each pass and it seems to be doing ok with that.

What speed and feed would you guys use?

I’m still learning a lot about how to operate a CNC since this is my first one. But, one thing I’ve seen is a smaller bit can work better; i.e., 1/8", for instance. Another thing is the length of the bit. I have a stock of 1/4" and 1/2" bits because I have used routers for woodworking forever. So, when I got my SO2 set up, I began with a 1/4" spiral upcut 2-flute bit 2" long and found out that was just too long for this type of machine. Shorter, 1/8" bits work much better with no chatter. I’ve worked up to 30ipm so far with no problem. Depending on material, I’ll use a cut depth of .0625" or .03125" per pass.

Another thing on bit length: I bought some 1/4" V-bits - regular router bits - for V carving. Being regular router bits mean the shafts are about 1.5" long so they stick out of a CNC spindle quite a lot. I used a hack saw to cut about 3/4" of the shaft off so the cutting edges of the bits are closer to the collet.

I can figure that out for you but there is some more info I need.

Spindle RPM
Width of cut (WOC)
Tool stick out from the collet
distance from bottom of spindle motor to bottom of tool.
Tool material HSS or Carbide

One of the big problems with pine is as you have discovered when cutting against the grain or cross grain pine will tear out badly.


Spindle RPM =14000
Width of cut (WOC) = ? not sure what this is? 1/4"?
Tool stick out from the collet = 1.5"
distance from bottom of spindle motor to bottom of tool.= 3.5" i think. 2" from bottom of spindle motor to bottom of collet + 1.5" for bit
Tool material HSS or Carbide = carbide

Plugging those numbers into Gwizard running conservative speeds

Depth of cut (DOC) .05
Width of cut (WOC) .25
Feed rate (IPM) 103
Plunge rate 51

Now with the stock spindly spindle that X-Carve ships with you will never get the that feed rate. You may improve things a bit if you can reduce your tool stick out to 1" or better.
If I am reading @BillArnold correctly you are limited to .5" of your tool fitting in the collet before it bottoms out. That is not good.

Also as Bill said a 1/8" end mill that is much shorter and has half the WOC your 1/4 has would work better. You would just need to change the tool paths in what ever CAM program you are using.

Gwizard slows the feed rate down to 74 IPM. Your spindle speed is only giving a surface speed (SFM) of 458 where as the mfg’s surface speed call for 1500.

That translates to close to 50,000 RPM for the spindle and you could travel at 110 IPM if you had that kind of spindle speed. Don’t know of a spindle that will move that fast but a trim router in place of you stock spindle that will do 30K would be a vast improvement.

Ow and loose the pine worst wood in the world :smiley:


Well it did seem to like .05 and 80ipm. I had been trying slow deep cuts with no success so i guess i just needed to go the other way

Carving shallow and faster will perform better than deep slow.

i had read somewhere that depth of cut was supposed to be the diameter of the bit so a .25 bit would have a depth of cut of .25 obviously this isnt the case here. still learning! :blush:

A good rule of thumb for depth of cut would be half the diameter of the bit. Going slower is not “better”. You want to be continually engaging the cutting surface of the bit. If it is going to slow it will be rubbing.

We working on a better way to calculate the speeds and feeds paired with bits, spindles, and materials in Easel.