Struggling to get lofts to do what I need

Martin_29

I have been trying to create a loft between two profiles but the behaviour is just not doing what I want it to do. As you cann see from the image, instead of doing a straight connection it is choosing points lower down which is creating a ridge on the shape. I have tried adding points and selcting those but the loft fails saying selected points are not on profile. I added point to the profile but that doesnt work either. I guess alot of the issues are caused by the way I may be drawing the item but I needed to sketch it from an image.
If anyone has a good tutorial on the loft tool I would be greatful as no matter which ones Ive watched on Youtube, I just cant seem to get my head around them. 

Thanks for any help.

Drawing is here https://cad.onshape.com/documents/34859a32c7246c6c43f25d29/w/67db315e3356eab850bfc27b/e/7d78444f1145472a5710ec4c?renderMode=0&uiState=66938f9cdeddc373f7241f9a

robert_scott_jr_

Looks like you got it fixed. Looks good! - Scotty

GregBrown

The part in the document link above is not so clean (or done?).... Have a look at the various diagnostics for measurement, curvature combs, zebra stripes, etc.

Like most Loft problems people ask for help on here, it is worth looking at the Connections option. Instead of using picked vertices, you can choose two edges for these connections, then roll the manipulator along the edge as appropriate.

However before you try and patch this up with Connections, you need to address the curves themselves. There is a fairly severe mismatch between the profiles which is causing things to go awry. At the heart of it is the overly complex spline curves (have a look at curvature combs --> Shift-C)...  How did you create these? Did you use the Sketch 1 scan as a guide and manually digitize in Sketch 2 and 3?  In fact, there is a gap between the vertex and edge (see below) which is larger than the tolerance the Onshape modeler considers coincident which is making me wonder how these were constructed.

Martin_29

Thanks for the reply.Yes I did scan the image in on sketch 1 and draw the profiile using the spline tool to draw the shape. Couldnt really get the correct shape using any of the arc tools. Sorry but i dont really know what you mean by 'there is a gap between the vertex and edge'