Extruding and capping (patching?)

[Dan_brannan]

Hi

I'm new to Fusion 360 and I'm a bit stuck. I apologise upfront for the incorrect terminology/not having a clue what I'm doing. 

I am designing a spacer for an engine casing, which is essentially piece of aluminium 25mm thick with some bolt holes in it and the middle cut out of it. I have drawn the sketch reasonably successfully however, if I try and patch it (which is what I think I need to do to 'fill' it in), Fusion 360 just hangs indefinitely when I select the sketch. I assumed this was because my sketch contained too many lines so I simplified it a bit but it still hangs. I'm sure it's something I'm doing wrong rather than a bug but I'm unsure what.

Also, if I try to extrude the sketch to the desired 25mm from the surface menu, I get the error:

Warning: Some profiles failed to create tool bodies
The extrude profile is not valid.
Try changing the profile.
The extrude profile is not valid.
Try changing the profile.

Is what I'm trying to do even correct? I just need to make the shape I sketched into a solid piece of aluminium with no open ends, 25mm deep. I have attached my exported f3d file.

Any help is much appreciated.

Thanks

Dan

[laughingcreek]

he 2 sketches that appear to have any geometry in them are pretty rough.  terrible curvature quality, micro lines, probably lines laid over each other, gaps to small to see, no constraints, etc etc.  they look like imported curves, which can be problematic.  I doubt you'll get anything useful out of these as is.  I would draw a new sketch using only native fusion sketches curves.  have you been through any of the tutorials on creating sketches?

[TheCADWhisperer]

@Dan_brannan 

It appears that you have several (unconstrained) sketches where you probably only intended 1 or 2 sketches.

Your sketch C251 has hundreds (thousands?) of tiny lines rather than smooth curves.

How are you creating your sketches?

[Dan_brannan]

thanks for the replies.

What I did, and you may laugh, was  to scan the part in a photocopier/scanner to get the outline. I then ran it through an online image to dxf converter. This wasn’t entirely laziness - the tolerances aren’t super tight but I need it to be accurate to within say half a mm otherwise it will protrude from behind the part it spaces out or the holes won’t align so I was worried if I just manually traced the image in fusion it wouldn’t be accurate enough. 

i have looked at some of the tutorials but I’ll confess I don’t understand what constraints are

 thanks again

[Warmingup1953]

Can you share the Scanned image? and note on it any two known exact dimensions

[Dan_brannan]

Here's the image I used. This is a cleaned up version of the original scan.

[davebYYPCU · Accepted solution]

You will be far more successful using that Canvass, than you were obtaining the rubbish from the dxf converter.  One sketch.

Load the Canvass, trace the holes and the offset boundaries for the holes and join the perimeters.  When done the sketch should populate with a blue shading.  The shaded profile will Extrude as expected.

Might help....

[Dan_brannan]

Thanks. I've done what you suggest and it's been more successful. I've managed to patch and extrude the shape however I can't cut the middle out of it. It thinks it's one face. I did make this work somehow the first time and I was able to select it and press delete on the keyboard but I had to go back to scale the sketch and now I can't seem to retrace my steps

[davebYYPCU]

If done right, you should be able to mouse hover / select every region independently, 

So if you click in the border area, the spacer that you want, does it select the correct region, I suspect that inner border outline has an unknown boundary gap / hole in it.

So make one of the outer border sketch articles, a construction type ( temporary) did all the shading disappear ( other than the circles) 

If so you divide and conquer the inner perimeter, close the gap so that the shading returns for that inner boundary.  When that is successful, change the temporary construction article, back to normal.   The border region should Extrude.

I don’t understand why you are in Surface mode, for a 25 mm spacer.

Might help.....

[Dan_brannan]

Thanks for your reply. No when I click the border area it selects everything including the inner.

I've been round the inner multiple times - I can't see any gaps in it. I can't see anywhere a sketch can be made construction - there's an option for hiding construction geometries?

 Does it matter that my inner and outer boundaries are in two separate sketches?

[laughingcreek]

probably time to attach your latest attempt.

[davebYYPCU · Accepted solution]

More than one sketch will never work, when asking for the features like this job.

The problem with the converted dxf was the same, 3 or four sketches to make up the overall document.

No everything in the same sketch.  Edit the last sketch, and Sketch > Project > Project everything in the other sketches.  Will be purple so you can use eyeballs to check you have everything in the same sketch, then it will be so simple.

one sketch per feature, one body, with holes for bolts, needs everything in the same sketch.

Might help....

[Dan_brannan]

Thanks for everyone's help. I have achieved what I needed - once I moved everything into one sketch everything started behaving itself. I had to copy and paste though, project didn't seem to do anything but I'm sure that's just something silly I'm doing. Thanks again

File is attached if anyone's interested. 

[TheCADWhisperer]

@Dan_brannan 

You traced this with splines?

I will make significant wager that the original was designed with simple lines and arcs. 

(Easier for CNC and for Inspection and for Editing.)

[Dan_brannan]

I did it with splines yeah. I didn’t know any better 😭

[TheCADWhisperer]

@Dan_brannan 

Also, when I dimension the circles for the holes the dimensions do not match standard drill sizes?

(I checked as inch units too.)

Is there a gear(s) or crankshaft that goes through this?

How is it centered in the assembly (do you have a picture)?

[TheCADWhisperer]

@Dan_brannan 

I sketched some circles (untrimmed) that would replace a lot of the spline points you have...

 As a machinist this is the type of geometry I would expect to see to make the original casting mold.

All circles, arcs, tangent fillets and straight lines.

[Dan_brannan]

Thanks! You are quite right in that there is a pin which runs through the larger hole into a recess in the casing which centres it. As this is just the spacer I’ve just left enough room for a sliding fit. The bolt holes are indeed oversized - they’re m6 bolts but the holes in the original casing are also oversized so I’ve just made these match. No idea where they got 7.44mm from