What's best way being able to return to non filleted or unioned objects?

Should one need to alter a fillet or an object that made up a union, what is best practice for being able to do so ?

e.g Can a fillet be undone later on and altered to a different radii ?

Can a unioned object be returned to the parts that were solids before unioned, one then altered then reunioned again ?


Those things would have to be setup parametrically and specifically to those situations – without breaking.

And V5 is pretty out dated atm.

I guess its save a copy of the file and union and fillet the new version.

Too close to the finishing line, and entering week 5 of what I had estimated as a 1 week build. far more complex than envisaged, so no room to go dabbling yet again in V7 and overcoming its issues, and is there a solution to ribbon twist lines, apparently not.

Stick to common sense and not things that might not work.


Extract and delete the fillet surfaces. Untrim the adjacent surfaces and then retrim where they intersect. Check object is closed and apply new fillet. Or, treat filleting as a finishing touch. Don’t fillet until all your geometry is complete. Then you can save everything in one go in its pre-filleted state so any surfaces that need refilletting can be reimported.


Sure, either isolate it into an archive ‘file’ or ‘layer’.

5 weeks isn’t that much time in the grand scheme.

There’s always room for V7, and V8. What issues?


It’s common for CAD users to spend weeks trying things that might not work, especially 10-15 yrs ago when hardly anyone bothered doing real threads, and people were baredly 3d-printing anything.

I have had to overcome these, some now solved:-

What to do to V5 dims in existing files for open into V7? - #3 by Steve1 solved
What settings to make shaded same V7 and V5? - #7 by wim solved
Draw line on Y axis shows either side of Green
Rhino V7 (WIN) vs. V5, why does my line anti-alising look trash? - #10 by Steve1
What model space scale should default Rhino V7 be? - #3 by Steve1
V7 circle selected it get UNWANTED control points dashed line box - #3 by Steve1 solved
What setting to stop lines looking like twisted ribbons v7? - #3 by Steve1



Hi Tom,
wrong thread perhaps ?
(pun not intended but funny :smiley: )

You need the one on thread making etc.


yes it s fascinating…

especially 1:38 there is a magic vacuum sucker that allows high-speed handling and directing for multiple threads - but I sometimes handle other threads as well.

I press my thumb up, that you get your work done - good luck & kind regards -tom

(3D modeling “threads”, ‘inclined plane’ around a cylinder) In the context of physical science and mechanical advantage.

When discussing inclined planes in the context of screw threads on a cylindrical object, such as a bolt or nut, the connection lies in how the inclined plane concept relates to the mechanics of these threaded structures.

  1. Threaded Inclined Plane: Screw threads on a cylinder can be thought of as a continuous helical inclined plane. Imagine unwrapping the threads from the cylindrical surface; you would have a long, spiraling ramp, like an inclined plane.

  2. Mechanical Advantage: Just like a traditional inclined plane allows you to lift a load with less force by exerting it over a longer distance, screw threads provide a mechanical advantage. By turning a bolt (which has threads), you can move it up or down (or in or out) more easily than if you were lifting the load directly. This is why screws are used to secure things or hold them together.

  3. Knowledge: To effectively use screws, bolts, or nuts, it’s important to have knowledge of the thread type (e.g., metric or imperial), pitch (distance between threads), and thread profile (e.g., V-thread, square thread) as these factors affect how the mechanical advantage works and how securely the threaded components will hold together. Understanding these aspects is crucial in engineering and construction.

In summary, screw threads on a cylindrical object can be seen as a form of inclined plane, and understanding the mechanics and properties of these threads is essential for various applications in mechanical engineering and construction.

Hence, as per my point earlier is, as it was less common in the past (say 15 or so yrs ago), for 3D-modelers to bother adding ‘threads’ to their models.

But over time as competition grows and common sense grows, more and more 3D-modelers learn how to dedicate the time and ‘tuition’ necessary to achieve more and more advanced geometric feats by learning from their said dedication of time and energy to things that, at first, ‘might seemingly not work.’

In conclusion, if you want to setup 3D-models with the capabilities of things like:



All in an automated parametric fashion; well yes, to reiterate, those things can be done. But it’s not very intuitive with Grasshopper especially with R5 versus R7. So, it might be better suited for programs like Inventor, or SW, CATIA etc.

At least until enough Eto frameworks are born to compete with the obvious best suited solution on this matter, being parametric solid modeling programs.