@RickyBlender (RickyBlender) posted a new topic, subject "how to model this cylinder head". It read:

   here is a cylinder head in 3D
    
    how to model the angle fins around the cylinder
    
    first idea would be to use curves 3D
    
    but may be there is a better way ?
    
    any ideas welcome to help model this !
    
    [ATTACH=CONFIG]133008[/ATTACH]
    
    thanks happy 2.5

Then @dleri (dleri) said

    I would not use curves 3D but instead do a series of extrusions where the fins are supposed to go.

So @RickyBlender (RickyBlender) replied

    still have to place the fins in 3D
    
    so how do you go about that !
    
    the bottom part is symetrical so i can use the spin tool  
    but for the upper parts it's a lot more complicated !
    
    [ATTACH=CONFIG]133029[/ATTACH]  
    thanks

To which @pappy (pappy) replied

    One way to do this is using the solidify modifier to create the fins. Crude test of course.
    
    ### Attachments
    
    head.blend (582 KB)
    
    untitled.png960×540 192 KB

@RickyBlender (RickyBlender) replied

    ok looks like something new in 2.5
    
    can you give more how details how you use this solidify in 2.5 to achieve the desired shape
    
    mind you i just found a hyperparabola shape  
    or saddle shape for the middle of this strange shape  
    so that would give me a kind of guide for the middle part !
    
    looking at your dwg  
    did you use shrinkwrap on some bands around the upper circular part then use solidify on these bands?
    
    looking at dwgs for this piston head and it's not 100 % round  
    the inside middle part seems tobe more squarish!
    
    thaks happy 2.5

After which, @ridix (ridix) added

    Actually this kind of cylinder heads is made with casting. Probably, master mold maker was given outside / inside dimensions with how many fin to add. The rest was his hand craftsmanship! Hell of a work!
    
    So, ya, you need to cut those fins one at a time to match it like he did!

@RickyBlender (RickyBlender) replied

    be back later on  
    still experimenting with some saddle shape to get the top middle part and see how ti goes!
    
    but it's a hec of a 3D shape to model !
    
    got the old script to work again in lastt built
    
    see pic
    
    [ATTACH=CONFIG]133157[/ATTACH]  
    sonow i can begin to play with some saddle shape for the top part  
    and see how to add some loop i guess to make the bands around for the fins!
    
    happy 2.5

@RickyBlender (RickyBlender) replied

    got this shape now
    
    might need to shrink wrap or retopo !
    
    [ATTACH=CONFIG]133165[/ATTACH]  
    happy 2.5

@Artkansas (Artkansas) replied

    That's a beautiful motor. Motorcycle? Airplane?

So @RickyBlender (RickyBlender) replied

    [ATTACH=CONFIG]136377[/ATTACH][ATTACH=CONFIG]136373[/ATTACH]trying to make the M18 Tank's engine
    
    but i finally had to do a lot of hand retopo
    
    but looking nice now

Then @RickyBlender (RickyBlender) said

    how can you do that
    
    here i created the saddle = middle top of cylinders first then added the fins afterward!
    
    the loft tool may do the oppsosite i think
    
    you make the curves then the mesh will follow it !
    
    then you have to extrude the fins along main axis  
    which i had to do my hands cause normal or extrude did not really work nicely in this case  
    even tried with shrinkwrap and not good either!
    
    did some basic retopo to begin with but then i modified it by hand to get proper shape  
    and fins extrusion

Then @greyoxide (greyoxide) said

    That whole thing can be formed by using 2 lattice modifiers in like 10 minutes.

So @RickyBlender (RickyBlender) replied

    then can you detail how it can be done with some good precision  
    this is a mechanical model with high precision
    
    but might be interesting to do it with lattice!

Then @ridix (ridix) said

    Actually, any type of deforming method doesn't work well; if shape the cylinder using deforms all the fins will come out deformed. Some parts of fin will be thicker than other part. But actual cylinder fins have constant fin thickness all over.

After which, @RickyBlender (RickyBlender) added

    did not see one like this engine lately  
    may be at next Airplane show in town i can see one!
    
    but usually fins are thinner at the tip then the root!  
    which i did not do in this case yet but may modify it later
    
    don' t forget the top is a precise saddle shape
    
    that strange shape migth be found in some 2.5 addons but nto certain!  
    but in this case i did my own script to get it see post 7


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