Wood Milling Logic Assistance

Started by evg, February 12, 2020, 07:58:04 AM

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evg

Hi,
I need someone to breakdown the logic for a simple flat plane toolpath stepdown to mill an area of wooden surface(same as cnc router) . I am wondering how to mill to a specified depth. is it based on # of stepdowns or velocity of wrist motion? I know it is trickier than milling foam surfaces..any clarification is welcome.

Thanks.

Johannes @ Robots in Architecture

Hello,

Your Grasshopper file is missing referenced geometry, which is probably in a *.3dm file.
Also, could you please clarify your question? I don't understand how the depth of milling would be depending on the wrist velocity of the robot?

Best,
Johannes

evg

yes, disregard my wrist motion comment. I am trying to think through milling logic of a simple plywood surface. If I were to define a shape in 2d lines to mill into the surface (Like a slot for example or groove) I would need to have drill bit radius to define "spacing" of path lines between shape boundary , I assume.
If I want define a specific depth to mill towards into the wood, would I need to incorporate a stepdown for my tool pathway as well? is this final milling depth dependent on a final toolpath height in my script or should I incorporate stepdowns to reach the desired depth of the toolpath in passes?

Thanks, and I hope this is clearer I am new to milling and kuka KR60.

evg

Updated Definition and rhino file, hopefully it makes clearer what I am trying to do

Johannes @ Robots in Architecture

Hello,

Yes, you need to incorporate the step down and tool diameter as a parameter that then changes your toolpath.
For a slot, as you did it, an easy approach is to offset the relevant sides and then extrude the volume that needs to be removed. You can then make e.g. contour lines through the object and put them into a zig-zag pattern.
Somehow related, attached is another example we did a while ago for a wood connection.
As always with programming, there are countless ways to get there, there is no "ideal" way.

Best,
Johannes

evg

I see, this was useful and I managed to incorporate tool diameter and stepdown, although, what would you recommend for multi notch milling? milling notches on multiple locations along a Wood board? I almost got the path working  but It seems the kuka is not milling down every notch.

have you had this issue before?

Thanks for your time again,

Erick

evg

Actually I think I made toolpath work for each notch on a board but, when testing on the KUKA it seems to not follow the path as shown on the file. it just comes down and then goes back up to home posiition. Any Reason.? Latest script attached

Johannes @ Robots in Architecture

Hello,

Your data structure consists of 5000 data branches, so currently you are simulating 5000 robots, each with one position. This is why the file only contains one movement.
Branched data structures show up as dashed lines in Grasshopper.
I have made some changes to demonstrate how to fix that. You will still need to adjust several parameters and flip the direction, as the robot is currently working normal to the slot, rather than parallel.

Best,
Johannes

evg

#8
Hi Johannes,

What you suggested seems good. I re worked my trees and data paths and I think it is very close to working at least on a single notch, later I will add solution to rest of notches.although I am having issues with the simulation in terms of the path being milled twice for some reason. has this happened to you before?

Thanks again for your time.


Erick

evg

attached is file

Johannes @ Robots in Architecture

Hello,

If you look at your contours, you make 10 contour lines for 2 surface (=20 lines), which you then divide into 2 segments = 3 points, therefore we are at 60 points.
Afterwards you looks for the closest point on one surface for the 60 points, and then again for another surfaces.
That gets you the 120 points, doing each process twice.
My recommendation would be to make sure that you differentiate between the layers through a tree structure. E.g. by grafting the surfaces that are plugged into the Contour component and then maintaining that structure.

Best,
Johannes

evg