Loft Cut guides question

george_3

I'm trying to transition one lofted cut profile to another along a curve and am having issues.  I've attached two pictures, in the first you can see the profiles I'm using.  The loft works but I end up with a straight cut line.  In the second picture you can see the arc I would like to use as a guide (orange).  Onshape will not generate the loft when I select the guide.  Any ideas?  Assume there is something wrong with the profiles.  Thanks in advance.

Jason_S

Try using sweep instead. Here is a quick example:


Let me know if you need more help!

Jason

george_3

Jason thanks but the image is not displaying in your post.

Jason_S

I posted GIFs, so your browser must not be able to display them.

george_3

Thanks, guess my issue with sweep is it doesn't seem to support a beginning and end profile for a transition.  When I select a second profile it just uses the first one.  That is why I was trying loft.

I found this discussion via search

https://forum.onshape.com/discussion/388/how-to-control-a-sweep-end-profile


Not sure replace face would help as I need it to gradually taper to the second sketch profile.

Jason_S

Ahhh I see. Replace face won't be much help here.

Try adding another guide to your loft to keep it in line. Make sure to use the pierce constraint when making the guides!

Best,

Jason

george_3

Jason, thanks again and sorry for the 20 questions.  Not exactly a pro.  Can you elaborate on the pierce constraint for the guides or point me to a tutorial with relevant info.  

Jason_S

In this document, I show what I think you're trying to do with Loft. I labeled my sketches to show my workflow while setting up the loft. I make a variable chamfer on the one side using a Loft and a Sweep on the other creating a constant size chamfer. In every one of the sketches, I pierced a similar vertex to what I would later use as my guideline.

Pierce isn't necessary for all projects, but its a great way to really pin down your lofts by making sure the sketch profile actually intersects the guide, as opposed to projecting the sketch to the guide. 
Pierce in help 
Loft in help

Good luck George!