topic Re: Conical lid with thread in Fusion Design, Validate & Document Forum

Conical lid with thread

montyonthebonty — Mon, 06 Apr 2026 00:43:06 GMT

Still fairly new to this and just trying to get my head around how to do this. What I'm trying to create is a tapered cylindrical bin with a lid that screws on.

The difficulty I'm having is extruding the lid downwards inside the bin matching the taper of the bin itself. I tried extruding down and using the bin to 'cut' the edge of the lid, but that gives me no clearance between the bin and the lid.

What's the best way to do this?

Thanks

Chris

Re: Conical lid with thread

davebYYPCU — Mon, 06 Apr 2026 01:13:53 GMT

One way, - best is up to you,

Coils can be tapered.

Build the thread and add the lid to it.

Might help....

Re: Conical lid with thread

TheCADWhisperer — Mon, 06 Apr 2026 02:52:31 GMT

@montyonthebonty

Can you File>Export your *.f3d file to your local drive and then Attach it here to a Reply?

Re: Conical lid with thread

Warmingup1953 — Mon, 06 Apr 2026 07:23:32 GMT

Thumbnail sketch? Or your best go at it

Re: Conical lid with thread

montyonthebonty — Tue, 07 Apr 2026 02:16:05 GMT

Attached is the basic shape I want to add a thread to.

I tried using this technique to get the thread, but couldn't get it to cut right - presumably because it was a solid and not a surface.

https://www.youtube.com/watch?v=8WW2_HtuV9A&t=308s

Thanks

Chris

Re: Conical lid with thread

TheCADWhisperer — Tue, 07 Apr 2026 05:38:45 GMT

@montyonthebonty

(view in My Videos)

Re: Conical lid with thread

TheCADWhisperer — Tue, 07 Apr 2026 06:32:32 GMT

@montyonthebonty

You didn't give any information about the threadform you are after other than tapered.

Are you attempting to duplicate a pipe thread standard?

Attached is one example of a custom thread.

Because of the conical taper you might not need or want the Offset clearance to achieve sealing. Or you might have to adjust based on your manufacturing process. (I am assuming 3D Printing.)

Re: Conical lid with thread

TheCADWhisperer — Tue, 07 Apr 2026 17:13:27 GMT

@montyonthebonty

This Offset clearance may not be needed as it the angle that performs the sealing.

Re: Conical lid with thread

montyonthebonty — Tue, 07 Apr 2026 22:59:52 GMT

Thanks for this

Yes, I had forgotten about the angle of the wall.

I'm trying to follow your timeline but I just can't quite get my head round how you're getting the bin to trim the surface.

Thanks

Chris

Re: Conical lid with thread

TheCADWhisperer — Tue, 07 Apr 2026 23:43:24 GMT

@montyonthebonty

I will create a video when I get a chance.
Is the circular thread form appropriate or do you need triangular or trapezoid or square?

Re: Conical lid with thread

montyonthebonty — Wed, 08 Apr 2026 00:38:07 GMT

Circular is fine, although I'm just trying to get my head around the principles for now!

Thanks

Chris

Re: Conical lid with thread

TheCADWhisperer — Wed, 08 Apr 2026 21:03:08 GMT

@montyonthebonty

(view in My Videos)

Re: Conical lid with thread

montyonthebonty — Thu, 09 Apr 2026 09:19:30 GMT

Good afternoon

I've watched that video several times and everything you say makes sense, but there's one thing that I can't get to work.

I've created the offset surface, used it to trim the helix, but when I try and do plane along path (and the subsequent sweep) it won't let me select just one edge - it tries to do it around the whole outline of the helix.

I'm sure it's something so simple that I've missed.

Thanks

Chris

Re: Conical lid with thread

TheCADWhisperer — Thu, 09 Apr 2026 18:17:16 GMT

@montyonthebonty wrote:
...but when I try and do plane along path (and the subsequent sweep) it won't let me select just one edge - it tries to do it around the whole outline of the helix.

@montyonthebonty

I forgot to mention to turn off Chaining...

(This image is for the Sweep, same for the Plane along Path.)

Editing your file I observe that you didn't set to 0 or 1 as instructed in the video...

Re: Conical lid with thread

montyonthebonty — Thu, 09 Apr 2026 18:56:04 GMT

Thanks!

It was the chaining that did it - I did try changing the number to 0 or 1, but it didn't work.

Playing with it now, I realise what I've done.

I did try unticking chaining (I wondered if it might be that) but because by that stage I'd already selected the edge, it didn't change anything.

I've just seen now that what I need to do is untick chaining BEFORE selecting the path!

Thanks for your help!

Chris