Tool Path Generation

Hi all,

I am relatively new to GH and I could really do with some help on creating a tool path for a double curved panel, having searched the forums I have come across some ways of doing this but these seem to have one issue which I need to be addressed for my application.

The grids which are produced using the methods on here follow the surface and tend to be equally spaced in two dimensions. What I need is to create a grid which keeps the distance between the path lines equal whether the angle between the lines is 90 of 45 degrees. At the moment the grids act a bit like contours on an OS map but they bunch up in the lower parts of the curves and spread out in higher parts.

Below is a picture of what I produce via grasshopper so far but using a grid formula from elsewhere on the forums along with Rhino to connect up the paths. In this example they seem equally spaced but they differ by anywhere between 0.755mm and 0.785mm which if scaled up would be a problem.

Any Ideas how to help me split the surface up equally in all dimensions, meaning that if I were to sweep the tool path with a circle radius of half the distance between the lines/rails, there would be no gap between the beads/filaments?

I appreciate any help or advice hugely.

Philip

Replies to This Discussion

Permalink Reply by Philip Valentine on November 15, 2011 at 8:03am

I forgot to mention that I am trying to keep all the work in Grasshopper rather than using other pieces of software

Permalink Reply by Philip Valentine on November 15, 2011 at 8:18am

Here is a more obvious picture of the problem I am having, the far right part is bunched up much more than the central part.

Permalink Reply by David Wood on November 15, 2011 at 8:22am

Hi Philip,

Have you tried the contour command in GH? Its relatively new.

David.

Permalink Reply by Philip Valentine on November 15, 2011 at 8:31am

David,

I have tried the contour command but it produces a series of points which are equal in, for example, the z direction but not equal in all axis. As far as I know anyway, there may be a way of changing this which I haven't come across it as yet. This means there is larger gaps at the crest of a curve and smaller on the larger gradient parts.

Philip

Permalink Reply by David Wood on November 15, 2011 at 8:54am

Philip,

I understand clearer what you mean now, sorry i didn't read carefully enough before posting.

Is this more like the kind of work you're doing?: http://www.grasshopper3d.com/photo/photo/listForContributor?screenN...

I recommend posting your files in this thread, it would be helpful to take a closer look.

David.

Permalink Reply by Philip Valentine on November 15, 2011 at 9:08am

It is similar to what I am working on, but I am looking into extrusion of a material to form the surface rather than milling, so having the equal distance between the paths is vital for my work.

So far I have used the equal divisions file but have recently changed to the tool path generation file, both have been from this forum, for use with the conversion to robot code using the KUKA robot GH file.

I have tried combining the two files and inserting the former file into the correct place in the later but it hasn't come out as expected.

So if anyone could fine a way of creating a tool path from the former by connection of the lines formed or combine the two correctly I will be extremely happy as I have been struggling with this for a few weeks now.

Philip

Attachments:

equal_uv_divisions.ghx, 186 KB
tool path generation.gh, 11 KB

Permalink Reply by Andres Gonzalez on November 15, 2011 at 1:54pm

Hi Philip

Try this:

http://web.mac.com/rhino3dtv/GH/GH_11_04_XForm_Project_Demo.html

What you need is the distance in between each CPlane on the floor. That is the distance of your toolpath.

So, make many CPlanes with the Divide Length component and then, find the Intersection in between the new CPlanes and your Brep! BRep | Plane component... BINGO!

Permalink Reply by Philip Valentine on November 16, 2011 at 7:48am

Andres,

I am trying to create a completely equally spaced tool path like the pictures i posted above, the path needs to follow the surface rather than being projected onto a flat surface, unless I have misinterpreted your post, if so then please educate me.

Philip

Permalink Reply by Andres Gonzalez on November 16, 2011 at 8:42am

Yes, that is what you get, the intersection in between the CPLane and the surface, a tool path that goes on top of the surface... On the Video, do not look a the projection, look at the curve on top of the surface... that is the Tool-Path. So, if you have a Ball End 6mm tool, and the step is set to 50% of the tool, you set up the CPlanes at 3mm apart... If this is not clear, I will make a short video!, but you will pay the Coffee for today! :-)

Permalink Reply by Philip Valentine on November 16, 2011 at 9:00am

Could you go over the steps to creating the path your way in a bit more detail?

I am slightly confused and not quite following you with all the GH jargon, as I said I am new to this and have had very little time working with it.

Permalink Reply by Philip Valentine on November 16, 2011 at 9:34am

Are you sure this way would produce an equal arc length between the lines rather than an equal linear distance?

for example I drew a pic below, I need the blue arc lengths between the lines to be equal rather than the green distances