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Lee Coll

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Posts posted by Lee Coll

  1. I am trying to create an aerodynamic "ring" that will represent the forward inlet of a jet engine nacelle.  The nacelle itself is circular in cross section and proved easy to model.  The inlet ring however is deeper at the top than the bottom.  I have attached an image showing the thick and thin profiles in their position above the rest of the nacelle.  How can I create a ring (or half ring) with the lower (right) profile and the upper (left) profile as shown?  I have tried taking a semicircle and changing it to a NURBS curve, to use as a path and using the small profile Extrude Along Path with an increase in scale of 1.5X as it sweeps 180°.  The problem is, the base for both profiles are identical in dimension.  Scaling it all, widens the extrusion inaccurately.

     

    Have also tried lofting, but no luck there, again using a NURBS semi-circle as a rail.

     

    Have also tried subtracting cylinders then loping a wedge out of the top to provide a tapered ring, which when filleted, does not come close to the profiles required.

     

    Any ideas?1844146101_ScreenShot2019-07-13at12_07_26AM.thumb.png.5d47f120c7dff62b85903100d5587ed1.png

  2. This is the first issue I've had using Loft Surface and considering the two NURBS shapes I'm trying to use to transform into a varying-section "elbow", I just can't figure out how to allow VW to accept the command, without de-selecting both items with nothing happening.  Both sections are NURBS that were converted from simple 2D shapes: the Circle is shown normal to the X-axis and the Oval (made from two circles and a rectangle, then joined as a single closed polyline) is normal to the Y-axis (Front).  So the planes where each NURBS entity exists are perpendicular to each other.  They are spaced to be transitioned to a curved exhaust segment, and I've used Loft Surface with No Rail (no effect) and created a Rail (that touched both edges - still no effect), and have yet to create the solid.  It just doesn't work and I've selected Create Solid (I will shell out later) with no result.  I must be missing something very simple here.

    Screen Shot 2018-11-04 at 7.32.58 PM.png

  3. Finally got it to work after Adding Solids, but for some reason on my previous attempts going this route, it just wouldn't work. I re-created everything and tried again and it worked on five of six spokes (why not the last?) that had been created with Duplicate Array. Third time was a charm.

    CanberraNacelleParts3D.jpg

    Here it is; overlaying a compressor face.

    Thanks for the really useful advice!

    Lee

  4. New here, so would appreciate some advice that would allow me to create a fillet between the blue spokes and the external hoop, both of which are extruded objects. I've selected a fillet radius that does not extend the fillet beyond the surface of the hoop, yet I'm still getting the message "Try changing the radius or turning on the select tangent entities option"

    Centralizer.jpg

    I have done filleting before with similar 3D extrusions, but have little or no experience with NURBS or lofts, which may be the route needed to perform the operation I require.

    Thanks,

    Lee

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