How to draw internal features on a cone

[Anonymous]

Dear all,

I am a real noob with Fusion 360 and have jumped in to deep water by attempting to draw a conical burr grinder for grinding coffee. I have managed (with the help of some files i found online) to create the internal burr, but am really struggling creating the features on the internal face of the outer burr which is a cone shape.

I have scoured the forums and the net and have found articles for drawing on internal faces of cylinders but cannot find anything to apply that to the internal face of a conical shape. 

I would really appreciate any help or advice that anyone can give me.

Thanks for taking a look and thanks to all the people offering support on Fusion 360, its made what would've been a nightmare, bearable.

Sam

[jeff_strater]

@Anonymous,

Can you provide some more information here?  Ideally, if you could share the model you have so far, and some image of what you are trying to model, there are lots of people here that will help.

thanks,

Jeff

[Anonymous]

Hi Jeff, 

Thanks for the quick response! I have actually been using the burr grinder you helped find the solution for (pictured below) as a base for my model. The Inner Burr you edited i have used (stolen 😕 ) and scaled down to my requirements but the outer burr i wish to alter for my design.

Rather than the cylindrical outer burr im trying to create a conical version that would sit virtually flush inside. I have created the cone (pictured below), but cannot figure out how to create the ridge design inside. Ive watched the video on how you did it for the inner burr but i cannot figure out how to do it to the internal face of the outer burr. Im getting awfully confused when trying to apply an offset or tangential plane to the inner face where i can sketch a line/arc to then extrude, and then create a pattern to replicate the ridge (apologies if using the wrong terminology).

 I have created a bodge job attempt ( pictured below but by extruding a sketched line on a tangential plane on the inner surface and then creating a circular pattern. However i don't think this is how it should be done and worry that it will not work with the design you modified for solution to the previous problem.

any help or advice would be greatly appreciated and again, thank you for the time you've taken so far,

Sam

[jeff_strater · Accepted solution]

Thanks, @Anonymous - my past returns.  That's great that you found and are using that design.

I did a bit of playing with this, see the screencast and attached model.  Basically, the idea for the inner faces of the cone is similar to the outer face of the inner cone:  Sweep + Project To Surface.  The Project To Surface command lets you define a path for sweep that lies right on that inner conical surface.  The other thing I did was to use a cut approach rather than a join approach.  Meaning:  make the initial hollow cone larger than necessary, then cut away material to make the desired geometry.  You can do it either way, but it always seems easier to me to cut away stuff, so that you know the inner surface will still be conical.

Anyway, here is the screencast, model is attached, it should provide at least some hints to get you started.

Jeff

[Anonymous]

Jeff, you are a true wizard sir 🙂 It didn't even occur to me to build a larger profile cone and cut/sweep into it instead of trying to join features like i did previously?! 

I will attempt my own version today using your technique so fingers crossed.

you've been a huge help and again, thank you so much for your time and help. If theres anyway to return the favour do not hesitate to ask.

Hope you have a fantastic Christmas and New Year whatever you are up to.

Regards

Sam