Help! How to create slots along curve

[Marty_McElveen]

I am trying to create slots along a curve that will be used as a cut pattern in aluminum panels using my cnc router with a 3/8 diameter bit. The slots would graphically show the pattern in Rhino, but a curve along the line is also required as a toolpath for the 3/8" bit.

A friend helped me develop a GH script a few years ago, but we could not get the slots to conform to the line at the points the line changes directions.

Is there a better way of doing this? One thought is to offset the source line on either side by 3/16", divide the curve with dashes, and create rectangles with rounded ends by offsetting the dashes 3/16" and capping them. I can not figure out how to do this, but perhaps this is not the best approach.

To take this to another level, can the slots (and toolpaths) be set parallel to multiple planes of an object? Ideally, I would like to adjust the slot sizes and spacing in real time on all 4 planes of the object in an effort to make a well-informed design decision as a whole.

Form with meandering polylines

Form with aluminum panels

Example of a panel with slots

Original GH script

Toolpaths of GH script

Slots of GH script

[inno]

please post the GH file with internalized geometries because it’s pretty complicated to understand things from screenshots

[Volker_Rakow]

My bad.

[Marty_McElveen]

creekside pavilion skin.gh (7.4 KB)
creekside pavilion slots.gh (3.4 KB)
241001 panel script.3dm (1.8 MB)

[inno]

the script you have works by orienting predefined slots all over the curve, but slots are just reoriented “as they are” so they can’t properly follow the curve when it has corners or similar

I would suggest an approach which draws the slots “one by one” along the original curve
something like this might be a starting point:

slots_on_curve.gh (20.7 KB)

if you want to use fractions for imperial units in the text boxes, something like “one and three eights of inch” shoud become 1+3/8 instead

[laurent_delrieu]

if you want continuity of slots on the edge it is also possible to use caped pipes like in this example
A bit more computer expensive.

How can I achieve this effect?

Re Hello I understand well your question, but what you show just a very simple geometry and no curve field at all. For the curve field I have idea, but the geometry type where you want to apply has some influence on the script. Also if you want to make this, like on you image, it is more simple to make some work on flattened (2D) curves. Booleans are more simple than in 3D. Whatever for the field there are many tools but I think the one have done on Nautilus are quite useful as they work on m…

Also Clipper is able to offset both sides (but it is polyline)

Clipper for Grasshopper and Rhino

Clipper2GH

[Marty_McElveen]

Thanks for the comments. Very helpful. I’ll implement and see what happens

[Marty_McElveen]

Your slot script works beautifully.

Is there an easy way to get equal distances between each end of the source curve to the beginning of the first / last slots along the line? In other words, can all slots somehow be centered on the source line so that the distances on either end of the source line are equal?

[inno]

this should do the trick (didn’t test it extensively though) it just calculates how many slots+spaces can fit along a given curve (n slots plus n-1 spaces), then subtracts that amount from the total length of the curve and splits the result in half to get a start offset value

slots_on_curve_equal_distance.gh (25.2 KB)

[seg]

Hi, you can use Dash pattern

dashed.gh (8.0 KB)