Extruding a taper.

douglas_michel320

First time here. I hope I'm posting correctly. Working on a school project and my question is...How to create a the below image. Material can be whatever at 3/32 thickness, around the circumstance (diameter 18") 1-1/2" in total height (adding radii last) of a circle> then extrude the edges or zigzag shape to a datum at the center of the circle. I was thinking after making the zigzag array perhaps on a plane 20" out from center> then array a single peak and valley. Then perhaps take a doughnut shaped extrusion with an inner diameter of 18" and outer of 24" and and a height of maybe 3" and have the doughnut subtract the excess material. Leaving the 18" diameter fan / zigzag. The below image is what I'm looking for which I did in Sketch up. Thank you for any insight.

MDesign

Loft one segment from a sketch to a point. Mirror that part. Then circular pattern.. to get it to work perfectly to you will have to do some math or setup some variables and use formulas.

glen_dewsbury

Here is one way to accomplish what you're looking for. Had to play around a bit to make it work. OS sees the fillets as folding over themselves or something as I tried to thicken. I cut a hole in the middle to adjust variable fillet ends.

https://cad.onshape.com/documents/ac0ecfe4f301c56899904542/w/f485e7914d309ca0473669c7/e/d68de12a3322acee63c9cc70

MDesign

slight change to my suggestion. create a cylinder and use a wrap surface for the base profile surface feature then loft to a point. I also had to make a small boolean subtract in the center to avoid non manifold error, but it doesn't matter if you change the instance count. the boolean doesn't know how to pickup the additional instances. Would be helpful if the circular pattern could merge with existing parts/geometry. If you finish the part with high instance count and include all the parts you can get it to a single part with many instance variations with just a warning of missing selections.

Was playing with variables. I left the sketch on in the animation to demonstrate what is driving the shape.

MDesign

Loft one segment from a sketch to a point. Mirror that part. Then circular pattern.. to get it to work perfectly to you will have to do some math or setup some variables and use formulas.

glen_dewsbury

Here is one way to accomplish what you're looking for. Had to play around a bit to make it work. OS sees the fillets as folding over themselves or something as I tried to thicken. I cut a hole in the middle to adjust variable fillet ends.

https://cad.onshape.com/documents/ac0ecfe4f301c56899904542/w/f485e7914d309ca0473669c7/e/d68de12a3322acee63c9cc70

MDesign

slight change to my suggestion. create a cylinder and use a wrap surface for the base profile surface feature then loft to a point. I also had to make a small boolean subtract in the center to avoid non manifold error, but it doesn't matter if you change the instance count. the boolean doesn't know how to pickup the additional instances. Would be helpful if the circular pattern could merge with existing parts/geometry. If you finish the part with high instance count and include all the parts you can get it to a single part with many instance variations with just a warning of missing selections.

Was playing with variables. I left the sketch on in the animation to demonstrate what is driving the shape.

douglas_michel320

Thank you so much, I'll be working on it Monday. Appreciate your time. Thanks again,

Doug

douglas_michel320

Thank you all for your suggestions, Being I'm just learning Onshape, I'm going to attempt all methods. Excellent practice for sure. Thanks,

Doug

MDesign

https://forum.onshape.com/discussion/comment/111018#Comment_111018

Mandalorian mode… "THIS IS THE WAY!" 😉

douglas_michel320

Woohoo! Not to bad for a first attempt

MDesign

Nice job. that was quick.