Need advice on creating sbp for spherical divots

[jbolyard]

Jay

You can actually V-carve with a ball nose bit... However you can only go to a depth of 1/2 the diameter of the ball. To go a full .375 you will need a .75 ball nose. if a true sphere is not necessary just pocket the circle with the 1/2" ball to .375 depth.

SG

"Right now - I only have Vectric and Cut 3d software"

not sure which software you are calling "Vectric"

Sorry about the software name - I meant VCarvePro and Cut 3D - both by Vectric.

When you say V-Carve - do you mean starting with the surface circles and creating a v-carve toolpath to a depth of 0.375 using a 0.75" diameter round nose? Will that give me a spherical divot with radius 0.75"? I do not want a flat bottom.

Thanks,
Jay

[steve_g]

Jay...

My attached drawing shows your options as I see them, other than creating a 3D file I think you were trying to avoid...

V-carved with a .75 ball will give you a flat on the bottom... V carved with a 1.25 bit gives you a .6125 deep dimple, and other than a 3D file, to meet your specifications will require a 1.41 bit to get a arc 1.25 diameter and .375 deep.

SG

[jbolyard]

Here's an example of a fluting toolpath to do it. You probably would want more spokes for a smoother finish but it shows you the technique. You can also do it with spirals.

Thank you! I took a look at your example - and also read/watched a few fluting tutorials. This plus the suggestion of a spiral... and voila!

I believe I've achieved what I was looking for.

A spiral vector created in Corel Draw - imported into VCarvePro via dxf - fluted with a 1/2" round nose. Change start point to outside instead of inside. Continuous/smooth flute.

I had to keep playing with the diameter of the spiral to end up with the correct diameter at the surface of the part - but I got it.

Here's the Vcarve file - predicted to execute in 33 seconds for each divot - that'll do nicely. I just need to test it now. Anyone see flaws in what I did?

Thanks to all for the help ---

I still have some programming questions about Master and subroutines though. Can they nest two deep? Is each call of a sub-subroutine still setting a new temporary 0,0 location?

[steve_g]

Jay...

exactly where I was going when I got called away for a family birthday party... The only difference I see was that I edited my spiral outer spiral to start on top of itself.

SG