Complex modelling approach

[SirEngineer]

Hello - was wondering if anyone would give me a few pointers. Wanted to learn Fusion 360 a bit, looked around and decided to draw one of my screwdrivers. Struggled a bit on how to actually model it and below is my attempt along with a picture of the actual screwdriver. If you look at the screwdriver, on each face is an inner profile. I extruded that and again at 90 degrees to itself. I then extruded the outer profile 'intersect' with the two inner profiles a both plan and 90 degrees if that makes sense. I then used 'loft' to fill in the hexagonal gaps between the inner and outer profiles - the faces at 45, 135, 225 and 315 degrees if looking from the end.  

Then extruded the hexagonal end cap where the blade goes and as it appears I missed the non-blade end cap, I revolved that but didn't do a great job. I was then hoping to 'fillet' the sharp edges but Fusion 360 won't allow me to, not sure why. Anyway, how would any advances users model this object? I'm sure there must be a better way but my limited modelling ability isn't aware if it

[g-andresen]

Hi,

Please share the file.

File > export > save as f3d on local drive  > attach it to the next post.

günther

[SirEngineer]

Fusion 360 file now attached....

Actually was thinking, perhaps it's better to have a circle at the non-blade end, draw the square-ish profile and then the smaller squarish profile, then the hexagonal blade end, then loft between all of the planar faces? I might try this later

[g-andresen]

Hi,

here´s one of many

günther

[SirEngineer]

Hi Günther, thats great - thank you. I was thought hoping to get specific modelling advice on whether there is any better way to model the screwdriver I pictured, as it's a lot of complex curves etc, not just your standard surface of revolution etc

[g-andresen]

Hi,

It is only one possibility of many.

günther

[TheCADWhisperer]

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@SirEngineer wrote:

I was thought hoping to get specific modelling advice ....

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1. Select a logical location for your primary datum - the Origin Center Point.

2. Fully define your first sketch (and of course, every sketch after that)...

Blue lines and white dots should keep you awake at night...

[SirEngineer]

Hi, yes you're right and as I am progressing, I'm getting better. Thanks for your feedback. Was hoping to get some thoughts on how to model the screwdriver though, it's quite complex due to the dimples etc. its got. Using the loft from a circle to the dimpled rectangle that is the largest cross section still doesn't even look like the actual screwdriver. 

[TheCADWhisperer]

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@SirEngineer wrote:

Was hoping to get some thoughts on how to model the screwdriver though...

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I can never progress without first establishing a robust and predictable foundation.

In my experience - skipping the foundation only results in frustration.

I can suggest a couple of step-by-step introductions...

Simple Geometry https://youtu.be/YiXJWB0NHxo

then after completing simple geometry - move into more complex geometry...

https://youtu.be/1rMxcK_No-A

After sketching is mastered - we can return to the screw driver geometry.

[TrippyLighting]

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@TheCADWhisperer wrote:

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I can never progress without first establishing a robust and predictable foundation.

In my experience - skipping the foundation only results in frustration.

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@SirEngineer you should honor that advise. You'll get there in the end but just stick to what @TheCADWhisperer has to say!

[SirEngineer]

ok, great instructional videos, certainly I will be constraining sketches better. Thank you. However, are you able to offer any tips on the screwdriver?

[kb9ydn]

Trying to put yourself in the mind of the designer is the interesting part of reverse engineering.  I think for the screwdriver handle I would take an approach like in the attached file.  Basically you start with a revolved form and cut away to make it more square-ish.  But you could also start with a square form and add fillets to make it more round-ish.  I think either could work really.  It just depends on preference and how you "see" shapes in your mind.

Sometimes it also helps to insert a picture of the object from different profiles to help with sketching the shape.  I've never actually done this in Fusion but I know it can be done.

C|

[SirEngineer]

Hello! thats fantasic - just what I wanted. A few days ago I redrew it doing what you had suggested, I started with a cube and cut away 4 sides, then another 4 sides (the shoulders) at the 45 degree angles. Wasn't without issues, rotating the extruded sketch 45 caused a headache and has distorted that sketch for alterations, although it worked. I think perhaps there would be a better way to rotate the cut body by 45?

Anyway, result was much better - but not perfect. I will review your approach with the extrusion of the surfaces etc, thats not something I was familiar with.  So I'm nearly there. Now struggling with extruding / projecting the manufacturer's logo on to the body etc. Fusion won't let me do it, not quite sure why, I have the logo drawn but won't cut from the body

[kb9ydn]

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@SirEngineer wrote:

Hello! thats fantasic - just what I wanted. A few days ago I redrew it doing what you had suggested, I started with a cube and cut away 4 sides, then another 4 sides (the shoulders) at the 45 degree angles. Wasn't without issues, rotating the extruded sketch 45 caused a headache and has distorted that sketch for alterations, although it worked. I think perhaps there would be a better way to rotate the cut body by 45?

Anyway, result was much better - but not perfect. I will review your approach with the extrusion of the surfaces etc, thats not something I was familiar with.  So I'm nearly there. Now struggling with extruding / projecting the manufacturer's logo on to the body etc. Fusion won't let me do it, not quite sure why, I have the logo drawn but won't cut from the body

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Regarding rotating the sketch:

If I understand what you mean; you created a sketch, used it to make a cut, and then moved it to make another cut?  If this is what you did then yeah, that's not a preferred way to make multiple cuts.  Moving sketches in general is problematic and it's usually recommended to not do that.  It's almost always better to use a pattern feature or even to just make another sketch.  And generalizing a bit further even; I try to keep sketches as absolutely simple as possible and do everything with features instead.  This is because sketches are by their nature more difficult to edit, and any edits are more likely to have unintended side effects since sketches are at the root of the shape creation tree so to speak.

About cutting with surfaces: 

This is probably a more advanced (and obscure) technique.  Most people would probably just add some extra lines (in the sketch that forms the surface) to make a closed box and then just extrude cut the box to remove the required solid.  The problem with sketching a box is that you have to make sure the box is big enough to enclose all of the solid you want to cut, which could be a problem if future changes alter the shape that is being cut off.  It really goes back to keeping sketches as dead simple as possible, to avoid having to mess with them in the future.

I also tend to start modelling with solids and then start using surfaces when the shapes get more complex, since surfaces give you more control over shape creation.

Not sure what's going on with the logo.  Would have to look at exactly what you're doing.

C|

[SirEngineer]

Hello, again thanks for the great advice. I interrogated your model and can see how you did things - simple 🙂 

My attempt using rotated sketches wasn't the best so started again, using c-pattern, bodies etc, much better, cleaner and simpler. Used the surface command as you did but found it temperamental so there is also like you said making an enclosed body and cutting that away. Managed to get the text to extrude too. So thanks for your advice. Nearly there - there are some dimples in the faces on the flat sides, I'm trying to work out how to model/create them now

ed to get the txt to 

[kb9ydn]

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@SirEngineer wrote:

Hello, again thanks for the great advice. I interrogated your model and can see how you did things - simple 🙂 

My attempt using rotated sketches wasn't the best so started again, using c-pattern, bodies etc, much better, cleaner and simpler. Used the surface command as you did but found it temperamental so there is also like you said making an enclosed body and cutting that away. Managed to get the text to extrude too. So thanks for your advice. Nearly there - there are some dimples in the faces on the flat sides, I'm trying to work out how to model/create them now

ed to get the txt to 

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Nice!  Looks like it's coming along well.  Many eons ago I worked in a bicycle shop, and one of the work stations had a Snap-on set with that same stubby phillips.  I'm remembering now that it had sort of scooped out areas on the handle where your thumb would go.  You can kind of see it in your original picture.  For those I'm thinking some kind of swept cut would probably be the way to go.  The fun part will be getting the profile and path adjusted to create the shape you want.  Fun stuff,  but it can be time consuming for sure.

C|

[SirEngineer]

A swept cut? I have been experimenting with a new sketch and cutting that away but not much success. Is this the way to go? I am not at all familiar with meshes, is it possible to make this area a mesh and manually modify? there are so many internet 'how to' videos, it's easy to see how to do something but not necessarily to understand 'what' to do to achieve the dimples which you correctly described

[kb9ydn]

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@SirEngineer wrote:

A swept cut? I have been experimenting with a new sketch and cutting that away but not much success. Is this the way to go? I am not at all familiar with meshes, is it possible to make this area a mesh and manually modify? there are so many internet 'how to' videos, it's easy to see how to do something but not necessarily to understand 'what' to do to achieve the dimples which you correctly described

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A swept feature is essentially an extrusion where the extrusion path is any arbitrary curve instead of just a straight line.  In order to do this you usually need two sketches; one for the profile to sweep and one for the path.  If you look in the help files it will have some basic info on swept features that should explain it better than I can.   They can be either surfaces or solids.  I would probably go for surfaces in this case, just like I did with cutting out the flat areas in the example I posted.

Mesh modeling is outside of my working knowledge.  The other guys in this thread would be better able to help you there.  It is possible this might be a more straightforward method than the sweep, but I'm not sure.

C|

[SirEngineer]

I'm stumped! I've tried many things, revolve, sweep along a path etc to get the dimples yet all turned out poorly. 

[TheCADWhisperer]

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@SirEngineer wrote:

I'm stumped.

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Attach the *.f3d file of your latest attempt here.