You are on the right track with that thinking.
I have noticed that phenomenon on a smaller scale on some of my 3d stuff especially on sloped areas and i made a correction with a much smaller stepover. I think I went to something like 10% (?)
Instead of recutting the whole piece, leave it zero’d, Make the stepover changes in the g code and re run the finishing file. If the current piece is kinda F.U.B.A.R. already what do you have to lose?
I use 40% bit diameter stepover for roughing and 10% bit diameter stepover for finishing.
It was the default settings in VCarve and I have stuck with it for good results.
Once I was getting excessive “ridges” in a carve and it turned out I had selected a end mill and not a ball nose. So if you are getting poor results always double check that you have the correct bit selected and loaded. (I once loaded a 1/8" bit instead of a 1/16" - duho)
I use VCarve which handles roughing and finishing passes differently:
In roughing you have Depth of Cut and Machining Allowance - a little extra thickness left for the finishing pass.
In finishing there is no Depth of Cut, assuming that your preferred depth of cut is the machine allowance from the previous rouging pass.
This makes for a few challenges. One I have to make sure that there is a bit of uncut material left under the carve (VCarve handles this in the material setup screen) so I don’t cut the carve free until the final profile pass (with tabs)
What I find works well for me is I do a 3 stage carve:
First I do a “Chip Clearing” operation. This is a normal roughing pass (40% stepover) with my larger bit leaving a machine allowance to match the preferred depth of cut for a roughing pass with my finishing bit.
I then do a single roughing pass (40% stepover) with my finishing bit, leaving a TINY machine allowance (say around .13mm) (To do this in VCarve i set the depth of cut to the material thickness so it will only do one pass over the already cleared material)
Finally I do a normal finishing pass with my finishing bit (10% stepover)
This seems to work really well and lets me use higher feed rates (though still not as fast as I would like )
(I hope that was helpful)
I tend to use the “parallel” pass first (same as VCarves roughing pass) then the “spiral”
Though one wood working video I saw the operator ran 2 parallel passes, one in the X direction then one in the X direction, to clean up “fuzzies” left on the wood.
I may be a Philestine, but you currently are by far the most prolific carver on this site! I really appreciate your contribution and if and when it comes to copyright issues, as long as my son’s room is the coolest on the planet, then let Walt and the lawyers forgive me. The only profit I’m making is the joy in my son’s eyes when I unveil a new project…
It’s often something simple and easily overlooked, then when you find it, it’s like driving out of a fog bank into the light of day.
I’m about to attempt a 3D carve. I modeled my object in Fusion, used the Easel post-processor and generated my gCode. (Admittedly, I did have to do this four separate times to get the 0,0 point correct for Easel - and chances are, I’ll do it at least one other time before it’s all said and done.) Now I’m playing the waiting game for my new ball-nose bits. They’re in the mail!
While waiting, I have time for some questions.
1.) Did you set up a custom bit in Fusion? Or did you use one of their standard, ready-made bits?
2.) Because I’m lazy, where did you find the step-over setting? (I could find it, but since I’m asking other questions, thought I’d just ask)
and, perhaps most importantly,
3.) I’m a bit stymied by how it looks like you caved your plaque without any tabs…did you just carve down to the depth that you wanted and then do a pass on a table saw to cut the plaque off the stock? I guess the real question is that it looks like you carved all the way to the bottom - how did you hold it down so that it didn’t move? Was it the carpet tape trick? Inquiring minds want to know!
This is only the third thing that I will have done with my X-Carve because I’m a jump-in-with-both-feet kind of woman (or just a glutton for punishment.)
Thanks, Phil. Hope my carve goes as well as yours!
Simply beautiful, love it. Has any one else tried your code? If not, I shure would like a go at it. Let me know.
That is a great design.
Look up the 1956 Cadillac emblem and then figure out whose lawyers should talk.
I understand completely, on the other hand would you have some tips for a biginner, like how you achieved the nice angle cut and which software you used. Thanks for any help you can provide.
Thank you Phil for the info.
At this time it’s above my pay grade intellect wise.
I will indeed try these techniques in the future, when I am more proficient with my X-Carve.
True 3D is so awesome, I want to do a big wooden nickel, eventually.
Keep carving buddy.