Thicken a (lofted) surface

Xavier_3

Hi,

I'm trying to model a funnel to help me pour coffee into a Bialetti filter. As the Bialetti is some kind of octagonal / circular shape I'm running into trouble modelling that shape (Not that I really need to functionally but I wanted to make a nod to Bialetti iconic shape.)

I started by modelling the surface of the middle & top part by sketching circles for the middle part and octagons for the top part and then lofting all sketches into surfaces that looks ok. I'm running into problem when I try to turn those surfaces into a solid. Just thickening the surface does not work (I understand that there would be some non-obvious issues at surface intersections). I then added some kind of "inside surface" with the hope of then filling the space in-between both surface with again a loft. But to no avail.

How would you proceed to 'thicken' such a surface?

PS: How can I link to an Onshape document?

michał_1

Hello Xavier, I can give you another method. When you need to turn set of surfaces in to a solid, try to build simple solid model with similar topology, and then use replace face command. Oyvind method is faster in your example, but in many other examples it won't work as you would expect. If you work a lot with surfaces I would suggest you to get familiar with my workaround. If you gonna know that trick (pros & cons) upfront, before you start modeling,it will come very helpful.
Here is my copy of your model:
https://cad.onshape.com/documents/56c2f121e4b0aa6155bc2015/w/51d4d744b30ec85072a9fd0c/e/cebe4728e5faf318b30323cb

øyvind_kaurstad

Linking is easy, just copy the URL of your document and paste it here. And the document needs to be public, of course. I'm sure someone can look at it and come up with some good suggestions.

Xavier_3

Thanks øyvind_kaurstad

Here's the link to my Public document: https://cad.onshape.com/documents/ab42958a9d8c7e8c1d8f4d56/w/0e76e409c5749d50a787098b/e/ef645e93001c7a35ddb695c7

øyvind_kaurstad

I looked at your document, and while I am not entirely sure what you really want to be the final result, you can thicken all the surfaces, like so:


Now, that gives you a strange looking shape the transition between the upper octagonal part and the circular part. You can the use the 'replace face' command on the bottom part of the strange shapes, and replace that face with the circular face. That will give you yet another strange shape inwards in the model, but you can easily just use extrude remove on that, and the final result is then like so (everything booleaned together):



Not sure if that helps you at all, though.  :-)

Xavier_3

Excellent. You did achieve what I was trying to do. I'll give it a go tonight.

NeilCooke

Quite often in these circumstances it is better to loft a solid then use the shell command afterwards. 

michał_1

Hello Xavier, I can give you another method. When you need to turn set of surfaces in to a solid, try to build simple solid model with similar topology, and then use replace face command. Oyvind method is faster in your example, but in many other examples it won't work as you would expect. If you work a lot with surfaces I would suggest you to get familiar with my workaround. If you gonna know that trick (pros & cons) upfront, before you start modeling,it will come very helpful.
Here is my copy of your model:
https://cad.onshape.com/documents/56c2f121e4b0aa6155bc2015/w/51d4d744b30ec85072a9fd0c/e/cebe4728e5faf318b30323cb

øyvind_kaurstad

Very nice (and useful) to see the different methods to achieve similar results. :-)

michał_1

Onshape don't have many tools that are useful for product design... but if we know the boundaries of the current toolset we can always adjust our workflow.

philip_thomas

Love this community - here is my contribution - the 'P' key is your friend (hide/show planes)

Xavier_3

Thanks all for your comments and help. I indeed wasn't using the replace feature. I'm not quite confident with it yet but knowing it exists and understanding that first use case should help me incorporate this feature in my modelling, thanks! Thanks also for the hide/show plane shortcut, I do not know how I was able to live without it.

I had my part printed (Actually, I directly printed michał_1 part as his modification of my document was precisely my design intent )

It came out as intended but I wouldn't say it's gonna be as useful as I envisioned it :P In the morning I always spill coffee grinds on my counter and I was hoping this little funnel could help me make less a mess. It works but it is not as convenient as I was hoping. Maybe a small incorporated leveller could be nice to level the grind surface?

    

wayne_poh542

I have tried  just lofted the octogonal shape, and use revolve remove the round area. this will give a better transition.
After the shape is form in solid, use the Shell command to hollow out the cavity.

https://cad.onshape.com/documents/4bd28ef4ca62adf3f7e7c714/w/507bd2f1e3f5e472745b3e46/e/7ac