I finished my first 3D Modeled piece using CC Pro. It was a 2.5 hour carve and all in all, I’m very happy with the output. I took these photos before doing any post-creation sanding, so that I could share the results with the community…First here’s the result…
Room for improvement…I’m not concerned about the fuzzy tops - that’s easily remedied with a quick pass of 220, but on closer view, the edges of every surface is scalloped.
I used a 45 degree finish pass with this bit, set as a 1/16" ball tip (which is the advice I had received because this type of bit is not supported directly by CC) at 50in/min, 20% Stepover, .050" cut depth.:
I’m guessing the experienced among you have seen this before and remedied it. Could you please share? Are better results going to come from a different bit? A different angle? Different speeds?
It feels good finishing one’s first 3D job doesn’t it ?
That tapered bit is excellent to finish “relatively flat” 3D surfaces, but not so great when it comes to finishing vertical walls (as is the case with your design). I wonder if in this specific instance, it would not have been better to do the finishing pass at 0 or 90deg angle. 45° forces the machine moves both X and Y in very small steps all the time, so it’s “jumping” around and it’s not a smooth as a single axis move. The stepper step size effect, coupled with the fact that you are moving a cone-shaped tool, may explain this.
I did vertical and horizontal passes for that thing below when I was playing with CC Pro and a similar tapered bit, and got relatively clean letters,
but the cone-shaped tool still left tiny marks if you look closely enough (those letter legs are 2mm wide):
It’s not. I’m still quite happy with the result - but want it to be better - certainly before using it on a piece I might sell. I’ll try using horizontal passes. I thought that cleaning on a different angle than the roughing pass would make things smoother…and all of the horizontal surfaces are beautifully smooth…but it’s the walls, as you point out. It’s a two and half hour job…so I’m not anxious to run it again…but there’s likely no way to learn other than just doing it!
I guess you could also try using a small ball endmill for finishing, you would get nice vertical walls and probably a pleasing little curve at the bottom of letters, and if you use a small enough stepover, the resisual marks would not be worse than the ones with the tapered endmill. The catch is of course that a 1/16" square endmill is much more fragile than a tapered endmill with a 1/16" tip, and the cutting length on 1/16" square endmills is usually quite limited. So it all depends on how the cut looks right after the roughing pass, and whether a square 1/16" endmill could safely remove the amount of residual material in one go (I wish CC Pro would let us specify depth pass for finishing to address this usecase)
Yes, that too. But honestly, in cases where a tapered endmill can be used optimally (i.e. when the 3D surface max slope is small enough), faking it as a ball endmill as you did does the trick. Modeling the tapered endmill would probably only show you (in the preview) what you already know (that cutting steep walls with it will leave a taper)
Since most of your design is 2.5D and with a limited number of different depths involved, I wonder if you should try and revisit the project to only do the sloped outside borders with a 3D toolpath, and use regular pocketing toolpaths for the rest? I think you could optimize cut time by doing this, as well as wall finish.
I thought about that in the beginning…but wanted to get experience with 3D. I like that idea for a real finished product though. I’ll work that project out as well and have it as a comparison.
but it will have an “outside” taper not an “inside” taper…
and an outside taper you can clean up with a straight bit (either as an earlier or a later pass)
now it would be awesome if CC would recognize “straight down” walls and make a toolpath to trace these explicitly… (it’s possible, I’ve prototyped that before in a different context)
I would need to create a 3D toolpath between the outer slope start (the thickness of the piece) and an offset square (inner) - to create the slope down in 3D…Then hog out the inside square to the letters / logo with 2.5 toolpaths?
Yes. Also, if productivity is an important driver here, you could look at using a V-bit to mill those four sides? A 60degree Vbit used for a contour toolpath running multiple passes, set on the inner box, would get you a very similar look, and better finish on those sloped borders.
I’m not trying to convince you to drop the 3D toolpaths, they are great for certain things, but they will invariably tend to last for several hours, so if time is your primary driver, it’s worth looking at regular toolpaths and aggressive feeds and speeds.
Time is not the key alone…Quality and time…finding that balance.
I really wanted to learn how the 3D modeling worked…which is why the logo was interesting because I made component parts show up at different heights (like the dovetails, the M in the logo, and the underside of the boards). That might be a little tricky to do with 2.5 toolpaths, but certainly doable if I put them in the right order. I’ll try it and see.
This is definitely well worth learning, to have that option when the project lends itself to it.
Of course another approach here could be to “just” use more agressive feeds and speeds ? Those tapered bits are quite rigid, so depending on what the roughing pass left behind, you should be able to bump the feedrate of that finishing pass. The easiest way if you do rerun that same toolpath, is to use feedrate override, incrementally increase it, potentially up to 200%.
I have a similar bit and it does leave that scallop.
Even if you go again at different angles. But for each time you change the angle and rerun the finish path, they get smaller.
