I need help lofting with guidelines

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  robert_morris OS Professional, Developers Posts: 166 PRO

  April 2016

  Lofts can be a tricky thing to get right sometimes.
  
  Here's a couple of ideas to try:
  1. Separate your guide curves into 2 different sketches and select the actual sketch not the individual curves when specifying the guides.
  2. Try also selecting "Match vertices" and selecting a vertex on each face sketch.
  3. Try re-ordering the face selection (Sketch1 first instead of Sketch 2). That's a weird one, but I've found it sometimes makes a difference.
  
  I would try #1 first, but it could be a combination of them that ultimately works.
  
  Hope that helps.
  

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  Graham_Midgley Member Posts: 1 ✭

  April 2016

  Try the Pierce Command at the ends of each line, it is difficult to draw inter connecting lines in different sketches, if the lines don't connect correctly the loft will not work, maybe post a link to your document so we can have a look.
  

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  chris_8 OS Professional Posts: 102 PRO

  April 2016 edited April 2016

  If you mouseover the red "Loft 1" text seen in your image, OnShape will give a general description of the problem. 
  
  If it says the guidelines must intersect the profiles, then some manual work needs to be done on all four sketches, manually telling those points of intersection to be coincident with both sketches.  Even though they seem to be coincident and maybe they already are, I usually need to manually create those additional constraints, or add a new point and make that be coincident with both sketches.
  
  If the error message says something about how a body that intersects itself would be created, then maybe more guides will need to be created.  This may be the problem at that bottom 90 degree bend area
  
  

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  chris_8 OS Professional Posts: 102 PRO

  April 2016

  Here's what I would do to make sure the guide lines were intersecting the profiles in a way that OnShape will recognize:
  
  
  

  Untitled-5.jpg 119.1K

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  chris_8 OS Professional Posts: 102 PRO

  May 2016 edited May 2016

  And one more thing I noticed that's causing issues for you:    The guides must each be one entry when creating a loft. In my example each guide was one curve, so each fits into the loft definition as an "Edge of Sketch 3".  However your two guides are 3 segments each, which requires 6 entries.    A way to make one of your line-curve-line combinations into a single entry would be to have each guideline in its own sketch.  So then instead of adding "edge of Sketch 3" you'd be adding "Sketch 3" as one guide, and "Sketch 4" as the other guide.
  

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