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Lines in Finish Project

Posted: Tue Jan 30, 2018 11:33 am
by drawersbydesign
I am new to the Forum so you will have to excuse me if this question has already been discussed. I have the Nebula router with the Air cooled Spindle. For my deign software I use Aspire by Vectric ( and maybe this is more of a question for there forum) My Question ... When I am doing a finish pass on anything 3D it leaves lines in the finish work, I will attach some pics of past projects. Here is what my settings are and what i'm using:
using 1/8"Ball Nose W/stepover .0075 or 6% ( I have tried almost everything from 4% - 12% Stepover with same results)
spindle speed 16000 RPM
Feed Rate 30.0 inches/Min
I am using raster (but I have tried Offset)
the diamond shaped pictures are on Soft Maple

any ideas what I could do or is this typical in this machine? any advice is helpful - thanks

close-up Diamond pic with lines
IMG_4027.jpg (74.85 KiB) Viewed 5262 times

Re: Lines in Finish Project

Posted: Tue Jan 30, 2018 12:17 pm
by drawersbydesign
also my Machining allowance is set to .03 when rough Machining on the previous pass-

Re: Lines in Finish Project

Posted: Thu Feb 01, 2018 8:06 am
by 4DThinker
When a lot of material is removed (by a roughing pass) I've seen boards bow upward as fresh moisture reaches the newly exposed wood. Knowing that could happen I typically set my allowance to 1/8" or even more just to make sure none of the roughing cuts are left after doing the finish pass.

If the board is wide, I've even seen boards bow (or cup) while a cut is in progress. I had a student project finish pass run across the project, then have to move back to do an area is missed on the initial pass across the material. The board had deflected enough that when the bit started on the missed area that whole are was a visible 1/32" or so higher than the rest of the top surface.


Re: Lines in Finish Project

Posted: Wed Feb 14, 2018 11:45 pm
by HANNAH024
I had a similar problem and tightened up the tolerance and the problem was solved.
You might try a tolerance of 0.010". It looks like it is moving in the xy plane before the Z has reached the programmed height.
Try it and let us know.

Re: Lines in Finish Project

Posted: Mon Mar 12, 2018 12:45 pm
by Skelly
Set the machining tolerance in the MDI command box with G64 P0.001. This really improved the appearance of my 3D carvings.


Re: Lines in Finish Project

Posted: Thu Apr 19, 2018 6:29 am
by HANNAH024
Just Wondering if you tried the suggestions and if they helped you?
I was working on the Rosette project the other day and thought about your problem.
I was getting great results and the finish was perfectly smooth, but it was taking a long time to machine.
So I decided to check something. In my windows computer, I opened a copy of the ngc cut file that I was running using notepad.
The post processor that I was using had a tolerance setting of 0.001inch.
The code in the program was G64 P0.001
I changed it to read G64 P0.075 and used FILE/SAVE AS to save the ngc file using a different name.
in doing a save as in notepad you must change the SAVE AS TYPE pull down from text to ALL FILES otherwise the ngc file will become a txt file which will not be recognized by LinuxCNC.
The result of changing the tolerance value was a major increase in speed but the cut was no longer smooth it had gouge marks like your original question. Needless to say, I changed the tolerance value. I changed it to G64 P0.010 and the result when I ran the new file was NO GOUGE MARKS with a faster speed than my original file but not as fast as the P0.075 tolerance.
Let the forum know if this helps with your gouge problem.