reducing diameter of a cylinder

[david.carlsen]

I've tried everything I can think of. Created a t-spline cylinder, want to edit it by reducing the radius or diameter, whichever. All edits I can choose permit me to change shape or move body but not to reduce the size of the radius or diameter. Sooooo non-user friendly. Any help is appreciated.

[jeff_strater · Accepted solution]

you can do this from the edit form command - set type to body, use the scaling handle that is orthogonal to the cylinder axis.  Screencast coming soon.

[david.carlsen]

Thanks, I see how that works.

[jeff_strater]

screencast:

[astro182]

There isn't an edit forms command, but it sure sounds handy.  Not sure how it would be possible to make this less intuitive - spending hours looking for commands that don't exist trying simply to create an open, tapered cylinder

[davebYYPCU]

Edit forms - T-Spline only.

Elsewhere, sketch, draw a circle, 

Extrude the circle with Taper handle or specify the known taper angle, 

press Enter.

Might help....

[TheCADWhisperer]

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@astro182 wrote:

There isn't an edit forms command,

….trying simply to create an open, tapered cylinder

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A cylinder is not “tapered”, that sounds like geometry commonly referred to as a cone.

Extrude with taper or Revolve.

I suspect that you have somehow found yourself in the wrong modeling area of Fusion.

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

And perhaps include an image or a link to an image of similar geometry that already exists in the Real World?

Solids - beginners

Surfaces - intermediate 

Forms (t-spline freeform) - experts who have mastered Solids and Surfaces over a period of months to years.

[astro182]

Hi davebYYPCU.



That was really helpful! The steps were easy and worked somewhat logically.
I was able to quickly make the rough shape. I'm trying to make a slightly
tapered sleeve.

The problem is that I don't know the 'taper angle'. Instead, I know the
narrow opening radius/diameter, the wider opening radius/diameter, and the
length of the sleeve (90mm sleeve with 47.3mm diameter opening on one end
and 45.3mm opening on the other). I could probably use trig to calculate the
angle and enter the degrees in the tool, but think there must be an easier
way.

Any other ideas? Sketching the length and both radii was easy, but it would
only give me a cylinder (closed on both ends), then I had to add holes at
each end which didn't work very well.

I really appreciate the help - learning how to use CAD is much more
difficult than I expected.

Clint

[astro182]

Hello CADWhisperer. I am greatly heartened that there's one such as you
willing to share the secrets of the cabal in this otherwise inhospitable and
perplexing dominion.

I've attached the v3 file that I ended up making since I wasn't able to edit
the measurements on my original (also attached as V2) - I only needed about
a third of a millimeter increase in the diameter.

My new construction (v3) was harder than the first since I could not
recreate the magic I used to open the open ends - instead I had to make a
cylinder, then put holes on either side so now I have unwanted lips on both
ends. I'm just trying to make a 90mm sleeve with 47.3mm diameter opening on
one end and 45.3mm opening on the other, with 1mm walls.

Is there an easy way to do this?



Thanks,

Clint

[davebYYPCU]

Use a Timeline and edits will be very easy.

(No files attached) Many ways to do it, 

Sketch the base Circle, with dimension.

Construct Offset Plane 90mm from it.

Sketch second circle on that plane, with dimension.

Use Loft tool, and Loft the two circles.

Use Shell Tool for inside or outside 1mm walls, select top and bottom faces to remove.

Else you could sketch a vertical section view and revolve a profile.

Might help....

[astro182]

I'll try your techniques - I stumbled on the Loft tool and thought it looked
promising.

So I'm sure, the only way to tweak a dimension is to use Timeline (or undo?)
to go back to the place it was entered, right? As soon as I click "Finish
Sketch" it's not editable in 2D.



Thanks again,

[TheCADWhisperer]

I would not use Loft for this geometry.

The most computationally efficient technique is Revolve.

Do you want to learn how to do this correctly?

If so, then I can make a video.

[astro182]

Sure - a video would be great! I found a few, like one making a drinking glass, but it moved through the steps too quickly.  And really wasn't super-applicable (lots of extra steps I'm sure)

[TheCADWhisperer]

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@astro182 wrote:

... but it moved through the steps too quickly.  

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You might not like my video - I went pretty fast.

Check >>this link<<.

[TheCADWhisperer]

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@astro182 wrote:

Sure - a video would be great!

---

Where did you go?

I specifically asked if you wanted a video before I took time out of my day to create it - and then you dissappear?

[astro182]

That's a great video - and actually addressed the part of the problem I hadn't included.  SOme steps moved a little fast, but I can trial and error a bit to make it work. Shell vs thicken may serve to meet my needs exactly.

I didn't get the post that said you uploaded the video, and the link was a little small.  Thank you for prompting me so I could find it.  The forum interface is also new to me.

Thanks for putting this together with a precise explanation of my application.

Astro182

[ilan1204]

Hi,

it is an old thread but maybe this could help someone. what i did to increase or decrease the diameter of the solid is -> Select the surface (diameter) -> q (Press Pull) and put your value. That's it. It works like Extrude 🙂

[astro182]

Hi -

Thanks so much for the reply as I never did perfect the process in a
repeatable, reliable way.

[TheCADWhisperer]

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@astro182 wrote:
Hi -

Thanks so much for the reply as I never did perfect the process in a
repeatable, reliable way.

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@astro182 

Why didn't you ask additional questions?

[astro182]

I had to take a pause in the project after damaging one of the pieces, and have been sidetracked since.  I hope to be able to resurrect the Fusion account once I resume, then will have to get smart on 3D printing with CAD again.  It's a very perishable skill (: