Bumpy 3D surface

Here's the place for discussion related to CAM/CNC and the development of the Path module.
Forum rules
Be nice to others! Respect the FreeCAD code of conduct!
Post Reply
Joneb
Posts: 66
Joined: Tue Aug 11, 2020 10:35 am

Bumpy 3D surface

Post by Joneb »

Hi Can anyone see what I have done wrong to get this bumpy surface, it,s not a major problem and can be sanded out but it would be nice if it was smooth.
I roughed out the bulk of the matrial with a 6mm ball cutter to the finished depth using the offset stratergy wit a 50% stepover then finised off with a circular stratergy with a 10% stepover. The material is hard wood and it is for a fibre glass mould.
As you can see from the GCode snippet the z axis variation gives the bumps.
Bumpysurface.PNG
Bumpysurface.PNG (443.65 KiB) Viewed 795 times

Code: Select all

OS: Windows 10 Version 2009
Word size of FreeCAD: 64-bit
Version: 0.21.31155 (Git)
Build type: Release
Branch: master
Hash: 6f1b29769b33676edca2bd883b80bed25a0758c8
Python 3.8.15, Qt 5.15.4, Coin 4.0.0, Vtk 9.1.0, OCC 7.6.3
Locale: English/United Kingdom (en_GB)
Installed mods: 
  * Assembly4 0.12.4
  * FeedsAndSpeeds-master 0.4.0
Thankyou to all the team for all the work on Path

Regards John
Attachments
MouldFrontFinish.FCStd
(1014.94 KiB) Downloaded 24 times
bmsaus4ax
Posts: 255
Joined: Sat Nov 14, 2020 9:16 pm
Location: Bargara, Queensland, Australia UTC+10

Re: Bumpy 3D surface

Post by bmsaus4ax »

Joneb wrote: Sun Mar 26, 2023 6:06 pm Hi Can anyone see what I have done wrong to get this bumpy surface, it,s not a major problem and can be sanded out but it would be nice if it was smooth.
I roughed out the bulk of the matrial with a 6mm ball cutter to the finished depth using the offset stratergy wit a 50% stepover then finised off with a circular stratergy with a 10% stepover. The material is hard wood and it is for a fibre glass mould.
As you can see from the GCode snippet the z axis variation gives the bumps.
An apparently strange question to begin with : does your gcode file, toolcontroller entry say "bullnose" tool ?
( bullnose tools give this result)

Your posted image shows a Ball endmill, but the uploaded file operation is stll using a Bullnose tool.

The generated path does not seem to be able to properly interpolate the combined flat and radial face of a bull nosed tool.

The bumpy surface results with a Bullnose shape
.
bumpy.png
bumpy.png (33.76 KiB) Viewed 737 times
.
.
A smooth surface is possible with a Ball nose shape
.
bumpy1.png
bumpy1.png (39.03 KiB) Viewed 737 times
chrisb
Veteran
Posts: 53920
Joined: Tue Mar 17, 2015 9:14 am

Re: Bumpy 3D surface

Post by chrisb »

bmsaus4ax wrote: Sun Mar 26, 2023 10:05 pm A smooth surface is possible with a Ball nose shape
Good find. You probably mean a Ball end mill here.

I had also tried with a smaller sample interval. That makes things worse:
SnipScreenshot-0a3874.png
SnipScreenshot-0a3874.png (23.36 KiB) Viewed 721 times
A Sketcher Lecture with in-depth information is available in English, auf Deutsch, en français, en español.
bmsaus4ax
Posts: 255
Joined: Sat Nov 14, 2020 9:16 pm
Location: Bargara, Queensland, Australia UTC+10

Re: Bumpy 3D surface

Post by bmsaus4ax »

chrisb wrote: Sun Mar 26, 2023 10:30 pm
bmsaus4ax wrote: Sun Mar 26, 2023 10:05 pm A smooth surface is possible with a Ball nose shape
,,,,,,,,,,,,,,,,

I had also tried with a smaller sample interval. That makes things worse:
SnipScreenshot-0a3874.png
In theory a Bullnose could be made to work if the stepover and step down were small enough to be within the radius of the radial corner face (the size of the radius not the physical radial position )

I have not tried this due to the processing and run times that would result. 3D surface is already pretty time intensive.
xemul
Posts: 393
Joined: Tue Mar 21, 2023 9:35 pm

Re: Bumpy 3D surface

Post by xemul »

IMO more convenient way is to make profiling for pads by a finest available tool and waterline for the rest.
You'll need to play with step down and sample interval in waterline operation.
I'm sorry for rough example, but I'm roped to antique L501x laptop at a moment, and any path calculations are really painful.
Profile paths from 3D Surface (Profile edges: Only) have a strong hiccup. I'm not a pythonist but try to look at a cause.
Attachments
MouldFrontFinish_xemul.FCStd
(836.73 KiB) Downloaded 20 times
Joneb
Posts: 66
Joined: Tue Aug 11, 2020 10:35 am

Re: Bumpy 3D surface (Solved)

Post by Joneb »

Thankyou every body for your replies my stupid mistake I thought I had set the tool to ball end as I new the problem with bull

Regards
John
Post Reply