How to create a recess in a cylinder?

[abennxxx]

I've created a torpedo-like cylinder (actually a wingtip tank for an aircraft) in Fusion 360, and now I'm trying to create some recesses in its sides.  I started off by creating a sketch on the vertical plane, which I had hoped to then extrude to the outside surface of the cylinder, but when I click on 'Finish sketch' I'm no longer able to select the sketched object for further manipulation such as extrusion.

Attached is a screen print of the design showing the new sketch which I want to create into a recess about 10mm deep into the cylinder.  How should I go about that, please?  Or should I starting in a different way?

[bwalker145]

If you're just having trouble selecting the profile (since it looks like it's in the center of the component), you could either:

a) hide the body first, click extrude & select profile, then show the body.

b) hover over the profile & hold left-click down until the selection menu appears, and select the profile.

[TheCADWhisperer]

@abennxxx 

Why didn't you use the sketch Slot command?

Is it your intention to have it underdefined and off centerline?

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

[abennxxx]

Thanks for those suggestions. 

I've managed to grab hold of the sketch and manipulated it to, I think, what I want using bwalker145's suggestion.  I'll be doing a test print of that section of the tube shortly to check it out.

But the answers give rise to another question:  How do I 'hide' a body or part of it?  I've searched the help file and it says I click on 'Transform' and then select 'Hide', but I can't find 'Transform' in my menus.  Do I need to pay for a Fusion subscription to get this feature?

As for 'Sketch > Slot', I didn't know that was available.  I'll try it out later.  In the meantime attached is my .f3d file for the project thus far.

[davebYYPCU]

Transform - neither can any of us - may have been in a particular context, usually means Move

In the browser listing, click the visibility eyeball for the particular object or folder, will toggle the visible status of the object.

or highlight the object in the window, and (type) Press the letter V on the keyboard.

Might help....

[g-andresen]

Hi,

1. check setting in preferences (hide sketch)

2. use slot tool an create its position and size

3. extrude/cut fom offset(from sketch plane)  and add another offset for depht

günther

[TheCADWhisperer]

@abennxxx 

None of your sketches are fully defined.

Check back in a few minutes for video of correct techniques.

[TheCADWhisperer]

@abennxxx 

Turn on your sound...

...next we will see how to start over from scratch and model correctly.

[abennxxx]

Thank you g-andresen and TheCADWhisperer for your videos.  They're very informative.

I've now managed to create my recess using the Slot command -- much easier than the way I tried to do it, though I did get a bit confused initially about the sense of the dimension required for the offset.

As for fully defining my sketches -- why is that vital?  My approach to this particular initial sketch was to start with the 0,0 origin at the centre of the shape, draw the first line 192.5mm (half the overall length I wanted), then go around using vertical and horizontal distances for the sloping surfaces (because that's what I had measured from the original model), instead of angles and slope distances until I closed the loop.  Fusion seemed to make sense of it so I didn't see the need to fill in the missing dimensions.  My second sketch was "attached" to the initial body by eye, so I can see room for improvement there by using the available functions you've demonstrated to attach it to the curve.

[TheCADWhisperer]

@abennxxx 

If your sketch is blue (under defined) then you haven't supplied all of the information another person would need to duplicate the geometry.

I made a big deal in my first video about reading out the illogical 15 place measurements of your model that can't possibly be measured in the real world.

Finally, if you aren't fully defining your sketches the geometry can accidently be dragged out of position without you even realizing that you made the mistake.

Without fully defining your sketch - you are building a house of cards on a foundation of quicksand.  Not robust or predictable and likely to fail as things get more complex in your designs.

[g-andresen]

Hi,

---

@abennxxx  schrieb:

My second sketch was "attached" to the initial body by eye, so I can see room for improvement there by using the available functions you've demonstrated to attach it to the curve.

---

By eye is not bound to an existing geometry.
The slot was “free-floating” and not bound to the cylinder.

If the cylinder is changed, the slot loses its relative position.

günther

[abennxxx]

Thank you guys.  I'll try to be more methodical in the future.

[abennxxx]

Thank you for those two videos.  I've just gone through the first two sketches in my model and have now got them fully defined, showing red padlocks.  Having no need for 'meassurable' angles I've simply accepted the multi-decimal-place values that Fusion has shown them to be.  Following the same principles I'll carry on with the remaining sketches.