How do I make a cone?

dosmandan

Ok, I feel dumb for asking, but I can't figure it out. Thought I would make a triangle, then use revolve, but the shape disappears.

Thanks!

tarek_mustafa

Hi @dosmandan, the way I did is to draw a construction line and than the half of a triangle as per below picture. Than, still in Sketch mode highlight the 2 blue lines and go the the revolve tool, the center line is the construction line.

brucebartlett

@Andrew_Troup  I Could not help myself. I did this with GifGrabber and on the Macbook with Trackpad (no mouse), but I am not still in bed.

Out of interest in this GIF I use quick keys (P) to hide planes and (shift E) to extrude. I could also have uses (s) for Sketch and (c) for Circle but chose to click.  

tarek_mustafa

Hi @dosmandan, the way I did is to draw a construction line and than the half of a triangle as per below picture. Than, still in Sketch mode highlight the 2 blue lines and go the the revolve tool, the center line is the construction line.

dosmandan

Much appreciated! I made a complete triangle, then tried to revolve. It didn't occur to me to try only two lines.

Thanks!!
Dan

andrew_troup

There's another way, now (as of today 

You can loft from a circle to a point, in order to model a cone. Or using the same idea, instead of a circle, an ellipse or a polygon (eg for a pyramid)

andrew_troup

It occurs to me there's yet another way to model a cone, which (on the face of it) requires an addition to the extrude options which is not currently available in OnS

I can confidently predict it will arrive sooner rather than later, not because of any inside knowledge, but because it is rather fundamental. I'm talking about 'Extrude with draft'

It's not as well known as it deserves to be that if you specify a draft angle in, say, Solidworks, but the depth of extrusion is excessive, the extrude will not fail, but simply extrude to a point.

I used to find this handy for modelling the conical ends of drilled holes in the pre-Hole wizard era, and also for chamfering hex nuts which have been formed, in one hit, by a solid extrude.

This can sometimes be a bit laborious to do with a revolve, as it requires the provision of an orthogonal plane (which may not be pre-existing in the more general case, rather than a dedicated nut), and a rather more fussy sketch.

My quick and dirty alternative involves a circular sketch, whose diameter is simply that of the small end of the chamfer, as the basis for a through-all cut-extrude with draft, flipping "side to cut" so it cuts away OUTSIDE the cone.  

The good news (having just "popped out" to Onshape CAD to check, without even having to get out of bed - yay for Chromebook/Onshape!) is that the same functionality is already available to us Onshapers as a two step process: extrude, THEN add draft separately.

If the extrude depth is excessive, no matter; the draft will end at the singularity, aka point.

Sorry for not posting a cartoon strip or animation; it would be unduly tedious without a mouse, and I haven't got any suitable software on my Chromie, nor would I know what to do with it if I did.

3dcad

Andrew_Troup said:

..

Sorry for not posting a cartoon strip or animation; it would be unduly tedious without a mouse, and I haven't got any suitable software on my Chromie, nor would I know what to do with it if I did.

It's just amazing how often people take time to create perfect screenshots / animations in this forum. It surely helps to understand even for us who aren't native english speakers..
@andrew_troup Take a look at this http://www.omgchrome.com/take-screenshot-chromebook-chromeos/ - works for me

jakeramsley

Andrew_Troup said:

It occurs to me there's yet another way to model a cone, which (on the face of it) requires an addition to the extrude options which is not currently available in OnS

I can confidently predict it will arrive sooner rather than later, not because of any inside knowledge, but because it is rather fundamental. I'm talking about 'Extrude with draft'

It's not as well known as it deserves to be that if you specify a draft angle in, say, Solidworks, but the depth of extrusion is excessive, the extrude will not fail, but simply extrude to a point.

This is how our system behaves if you apply a draft after making the cone.  Similarly, if your draft angle isn't large enough/extrude long enough you can apply a delete face to the top face and generate a cone that way.

There's a near infinite number of ways to make geometry in CAD.  I think the most important aspects for me is that the design intent is built into the method and that there is stability in the way it is made.  I often like to try to flip/modify the first feature that I have created and see if everything builds correctly after that.  If not, in my mind, I didn't create the features relative to one another well enough.

dosmandan

Thank you all for the suggestions, I'll give them all a try and see if one works better or easier than the other. I did try the first suggestion using two lines and discovered it would only create a surface. I needed to close the triangle to make a solid. 

Andrew, I'll give the "loft to a point" a shot first. Then try the others and let everyone know. 

Thank you for also joining in Jake! 

brucebartlett

@Andrew_Troup  I Could not help myself. I did this with GifGrabber and on the Macbook with Trackpad (no mouse), but I am not still in bed.

Out of interest in this GIF I use quick keys (P) to hide planes and (shift E) to extrude. I could also have uses (s) for Sketch and (c) for Circle but chose to click.  

3dcad

@dosmandan  You don't need construction lines when creating a cone. @Andrew_Troup has point if you create many cones in different position (hole bottoms etc.) but if you just need a cone here's a quick guide:

1. draw triangle
2. revolve (choose sketch face for face and vertical line for revolve axis)
3. set full revolve to create a solid cone (I just opened a bit to show it's solid inside)

See images below or inspect public model: link

dosmandan

Since everyone was so kind and helped me out, I'm sharing what I was working on with the group (well, everyone). I usually make these out of metal, for use in lift mechanisms I build. Wanted to try and model one and print it on a 3D printer.I need to put a split in the connector so it will snap in place.

Search in the public section under: Swing Arm

If you want to collaborate and have fun with the swing arm, I'd love to see what we can come up with. Here is a link to what they are used for: 

Werewolf Prop: https://youtu.be/MVB5V_MPcrY

DosManDan

david_sohlstrom

Dan   would it be easier and maybe stronger to change from a cone to a snap ring groove 

Dave

dosmandan

David,

I agree, but I haven't figured out how to make one yet. Was looking at the Cap someone created (MB Wheels Center Cap). Just have to figure out how they did it. I think you are referring to an E ring grove, and that would work as well.

david_sohlstrom

Dan

Take a look at this companies retaining rings. You can get free samples and a catalog.  http://www.smalley.com/retaining-rings/about-smalley-retaining-rings

Dave

andrew_troup

3dcad said:

Andrew_Troup said:

..

Sorry for not posting a cartoon strip or animation; it would be unduly tedious without a mouse, and I haven't got any suitable software on my Chromie, nor would I know what to do with it if I did.

It's just amazing how often people take time to create perfect screenshots / animations in this forum. It surely helps to understand even for us who aren't native english speakers..
@andrew_troup Take a look at this http://www.omgchrome.com/take-screenshot-chromebook-chromeos/ - works for me

Thanks, mate, I'll check it out.

MrDiLizio

If you need to make a truncated cone, I made a short little video that may help.

https://youtu.be/syvCmmdyZW0

EvanReese

Since this thread got bumped again, I invite people to check out my Cone custom feature too (there are also Sphere, Cube, and Prism features in the document).