Trouble with Loft Creating a Continuous Concave Surface

[Anonymous]

Hi,

Thanks for the help on my last post. I'm learning to define my sketches early so I don't run into as many issues. Currently, I'm trying to add a slight concave surface on a small part. In the attached image, you can see the concave surface is applied to the circle portion of the part. But I can't seem to mimic that with the rest of the part. I tried joining the faces before extruding but couldn't seem to get that to work.

In the image, within the red oval is where I want there to be smooth concave surface. I've attached the file as well.

Thanks in advance. 

-John

[jhackney1972]

Due to the change of shape between the circular edge of part of the loft to a straight edge on one side, I think you have the best you are going to get.  There is a definite change in curvature that will result in the two edges you see. If you turn off Shaded with Edges you can definitely see this curvature change.

[laughingcreek]

not entirely sure what your after.  look at the attached and see if it's in the ball park form wise.  this particular model isn't particularly stable because of on going buggy behavior with splines and tangent constants,  but once we understand the form you want we can probably come up with a better setup.

[Anonymous]

Thank you both for your replies.

I think I came up with something slightly acceptable, at least on the outside. It might still be a little messy underneath as far as the stability and overall "properness" of things are concerned. 

I'm hoping for the loft to sort of merge with the longer tab, a gradual contour. I've attached what I came up with. The results come from a smaller loft and a few fillets added. It seems close enough to what I'm looking for.

Let me know if you think there are any changes I can make to make it more stable or defined. I may purchase a small 3D printer to see how it actually looks and feels. Thanks.

 

[JamieGilchrist · Accepted solution]

Hi @Anonymous 

is this maybe what you're looking for?

I've attached my version of it.  I'd probably back through and clean up the model a little bit, but this version isn't too bad, IMHO. (expert elites, no judging 😅).

[Anonymous]

Thanks @JamieGilchrist ! That looks great. Not sure I could reproduce it; but I can spend plenty of time trying to figure it out. The surface loft was something I had in my head but didn't really know how to do. Glad to know that worked out.

I noticed the "hole" function won't work, or at least I can't get it to work, on that lofted/concave face. Instead, I manually created the countersink hole. I'll have to do some more tinkering. Oh and I attached a pic with a screw in place.

@laughingcreek and @jhackney1972 , thank you for your help as well!