Flats or Faucets on turning

[Woodmolds]

How do I get rid of the flats shown in the picture. I'm sure it's a setting in Rhinocam, but which one/where? The part renders in Rhino without these flats and the first machining passes do not have them, just last roughing and finishing.

I used the picture, because it better shows them than the wood part.



Thanks, Tony

[Hirudin]

That photo is the result of the simulated machining, right?

There is a setting in RhinoCAM that lets you change the rendering options for the simulation. Unfortunately I don't have RhinoCAM (or Rhino for that matter) installed at the moment so I can't find where the option is for you.

Look around in RhinoCAM for "Simulation Settings" or something like that. The simulation geometry settings should be in there somewhere. If I remember right the "inferior" option is called "voxel" and the better option is called "polygonal".

... Attached is a screenshot of the setting I'm talking about from the RhinoCAM 1.0 manual (sorry, I'm too lazy to find the 2.0 manual, but I bet the windows look similar).

Location of 1.0 manual: http://www.rhinocam.com/Downloads/RhinoCAMTutorial.pdf

[edit]
I hope this setting will fix the look of the model, but I'm not sure it will. I hope I haven't wasted your time.

[Woodmolds]

I had seen a tip about changing the rendering resolution(in Rhino), but it didn't seem to change the display, although it may have helped the actual part cutting. I'm not sure because I made some other changes at the same time. I did have the simulation set for polygonal. The picture is how the part was actually machining. I used the simulation because it better showed the facets than the picture of the wood part.

To clarify the part rendered correctly in Rhino, but the simulation in Rhinocam had the facets, thus the part did too.

Thanks for the tips, Tony

[DareBee]

I don't have RhinoCam.
If it is of any help, that is changed by decreasing the sampling resolution during model import in VisualMill. I would assume a setting that does the same thing "in essence" even though you don't physically import the model (like I do).

[Woodmolds]

I don't have RhinoCam.
If it is of any help, that is changed by decreasing the sampling resolution during model import in VisualMill. I would assume a setting that does the same thing "in essence" even though you don't physically import the model (like I do).

Thanks,
I'll look for that also.

Tony

[awerby]

that you're cutting and not just in the simulation, then you need to generate a finer mesh. This can be done in Rhino, when you save it as an STL file. A slider will pop up allowing you to choose to mesh it with more triangles. This will result in a smoother model without visible facets. RhinoCAM will work just as well with the STL mesh as with a Rhino NURBS surface.

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

[Woodmolds]

that you're cutting and not just in the simulation, then you need to generate a finer mesh. This can be done in Rhino, when you save it as an STL file. A slider will pop up allowing you to choose to mesh it with more triangles. This will result in a smoother model without visible facets. RhinoCAM will work just as well with the STL mesh as with a Rhino NURBS surface.

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

Thanks Andrew,
This is very helpful, as originally I was working with an STL file and could have done this as opposed to drawing it from scratch in Rhino.

So, if it's visible in the Rhino render or the Rhinocam simulation it will be visible in the machined part? Correct?

Thanks, Tony

[awerby]

Thanks Andrew,
This is very helpful, as originally I was working with an STL file and could have done this as opposed to drawing it from scratch in Rhino.

So, if it's visible in the Rhino render or the Rhinocam simulation it will be visible in the machined part? Correct?

Thanks, Tony

[Not necessarily. As the other guys were saying, the simulation or rendering settings can be set to "quick and dirty", which will speed things up at the expense of verisimiltude. The other thing you can try adjusting are Rhino's tolerance settings, which govern how accurately a part will conform to its specifications.]

Andrew Werby
ComputerSculpture.com — Home Page for Discount Hardware & Software

[xesxes]

Thanks Andrew,
This is very helpful, as originally I was working with an STL file and could have done this as opposed to drawing it from scratch in Rhino.

So, if it's visible in the Rhino render or the Rhinocam simulation it will be visible in the machined part? Correct?

Thanks, Tony

The facets in your part come from Rhinos mesh settings. I have 3 important points to discuss.

RhinoCAM converts your nurbs model to a mesh during pathing. This is a little sad because the beautifully smooth geometry you have is really just a lie.

To reveal your model for what it really looks like, to take away the veil, you need to turn on 'flat shading'. You will gasp in horror at what you see sometimes. You can find flat shading under the viewports label, where you find rendered, shaded, wireframe, etc.

You can improve this mesh! If you go into rhino options under display mesh I think. You have 3 options. Jagged faster, smoother slower, and custom. If I remember correctly these settings will affect your part.

This is the best solution I have found so-far, to produce a smooth machined part. You need to export your model as an STL file, I use export selected. When you see the tolerance setting, use a number like .001, The lower the number the tighter the mesh. Then put your NURBS model on it's own layer and hide it. "Import" your STL back into rhino and put it on it'd own layer.

Now you can use the nurbs layer to generate regions and the mesh layer to generate pathing.

Just make sure you turn off the nurbs layer and turn on the mesh when you are regenerating your operation.

Hope this helps, good luck.
-Travis