Ridges - help

having a bit of a brainfart here.. how do you make these ridges?

i tried drawing the side profile at first and it worked fine but the ovals on top were not perfectly round.. more like pill shaped, so i scrapped that method. ive gone with a simpler approach by just drawing the oval overtop and patterning it, and extruding down.. but im not sure what the next step is.

heres my file as a step, sorry the sketches dont transfer in the export but i extruded a couple on the end so you can project your own sketch from them.

ridges.step (108.3 KB)

thanks

Rotate a half ellipse, to get the body for subtract

im sorry, i dont think this is the answer i was looking for.

extruding the two ellipses down gives you a specific side profile that i am looking to achieve, kind of has a flat top. revolving it isnt the same shape, its too deep and perfectly cylindrical.

im just puzzled on how to round out the inside of my extrusion, or the correct way that this should be done. i would assume you use a side profile to cut into it, but its not something i can just guess on or it ends up looking incorrect. thats why i opted for the top down oval approach to hopefully achieve the side angle, but the two different radiuses cause it to have a different profile on each side. i think im just missing something basic here

heres my next idea: look from the side, select the edges of the profile and project it onto a plane. then use that profile and cut into the side. this is basically almost the finished product im looking for but since there are two differing radius sizes on either side, im not sure which profile to grab for the projection and the end result ends up not looking exactly like an eclipse - has a flat portion.




i am so close.. im sure i will figure this out but i thought someone might have a better set of eyes than i do.

HI,
Is this the kind of model you want?

Engineer :brain: side says nearly there. More cowbell.

Artist :brain: side says look deeper.

yes almost, but i am looking for the inner cavity to follow the profile, not extend lower.

Looking at the shadow on the texture of the walls. Mine is a little deeper but this is what I see. :man_shrugging:

the top view is an eclipse - you can download my step file above for the exact profile that i traced over a flatbed scan of the top. i know this is tricky, i dont usually ask for help here unless im totally lost :confused:

@jean-philippe2 was super close, but each ridge isn’t a bowl that goes deeper, its supposed to match the profile of the side

I think it’s an ellipse because of the body profile. :man_shrugging: My eyes are done with this day. You will get it. :+1:

I got stuck on your screenshot…
• Ellipse configurable. Ssee 2 Variables in History.
• Fillets and Pattern configurable to adjust number of ridges and space between them

Shadows do not lie. IMO they are not ellipsoid. Look at the highlight in the bottom of the trough. It’s straight. The shadow/ highlight would be an ellipse/ curved as well. The ellipse would have to be very very subtle.

Screenshot 2026-11-02 055636

First I think you might be overcomplicating it a bit. Your basically trying to reproduce a physical object that was maybe injection molded which naturally smooth out things which you are trying to copy and reproduce in CAD.

Second direct side photo would be nice, the ridges show they are straight presses on a oval shaped curvature, so top view is just a natural by product of the press. Also top seems abruptly flat which doesn’t match the side profile and the photos, which I think adds up to not looking right.

If you look at the original step file from the side the one side, the right side is slopped slightly sharper and uneven compared to the left.

Note the complete roundness at the top.

You can use Variables and Pattern in History To optimize your rendering

yes, you were correct. i think we were on the same page

someone having better eyes than me.. this is what i meant. i brought the radial corners back to sharp and recut the whole top to have a continual curve instead of having that flat top, and the flat portions were gone. i should have noticed this on my own screenshots of the top view, pretty obvious now after the fact


so, its finished now.. thank you everyone for the guidance

We were, just missed coms. :rofl: