A little help on this model please


#1

I am working on making this design watertight or hole free but am at a loss about how to do it. The model is constructed of extruded 2 rail surfaces and a boolean segment for the main body that was polar arrayed from a 45 degree initial segment? The check function says that it is a valid object, but it has holes or gaps. I tried to match surfaces to close things up but while I can select the extrude two rails objects I can’t select the main polar array structure. Any suggestions?


(Wim Dekeyser) #2

Your terminology is confusing (perhaps you have a background from a different 3D modeler?) and these pictures don’t really tell us all that much. Could you post the 3dm file?


#3

Sorry if the terminology is a bit strange. This was constructed by starting with a Torus and then intersecting forms were boolean subtracted from a 45 degree Torus section which was offset to create the thickness of the final form. Then I created connecting surfaces, some with a simple line that used the sweep 2 rails command, and others used a arc cross section again utilizing the sweep 2 rail command. I cannot get the additional surfaces tangent to the Torus formed shell, leaving gaps. Here is the fileCoral bracelet final.3dm (17.2 MB)


(Wim Dekeyser) #4

The original ‘cutters’ are no longer in this file and that makes it rather time-consuming getting back to something that can be used to fix this.

Your problems stem from the tolerance and units that you set for this project. The length of some of the edges that are created are well below the absolute tolerance and things go south quickly from that point. Use millimeters as units and put the tolerance to 0.001 units.

Then untrim all input geometry and start cutting again.

This picture shows some of the problems - a sure sign is when the isocurves do not reach or overshoot the edges of a surface.


#5

Wim, thanks so much for your help. I can see that the tolerance settings created the gaping issues that prevented the model from being a continuous surface. What I ended up doing was returning to the base mesh that was created in a poly modeler, Silo 3d and use the shell command in that program to create the structure before bringing it into Rhino and converting it to a Nurbs model. Thanks again for your help and expertise.