topic Re: Contour Surface with shaped edges in Inventor Forum

Contour Surface with shaped edges

NachoShaw — Wed, 14 Nov 2018 22:19:17 GMT

I have this shape (attached) that i seem to be struggling with. Its not the shape im having trouble with, its using the shape to create what i need.

So with the image above, there is a straight line on each end of the surface. The surface itself is twisted with a degree difference between the lines (as seen below)

I have to make 7 2" x 2" rails sweep from the LH line to the RH line while keeping the back edge of the rail on the surface. along with that, the top rail should follow the top edge and the bottom rail should follow the bottom edge. The spacing on each end need to consistent (not equal each end as the lines are different lengths)

This should provide a series of twisted rails that travel from the left to the right.

I cant do it, i have tried sweep, sweep with surface guide but it doesnt work.

Anyone have a good workflow or suggestion?

Thanks

Nacho

Re: Contour Surface with shaped edges

Xun.Zhang — Thu, 15 Nov 2018 09:14:07 GMT

Hello @NachoUK,

If you just want to have a series twist line, then, split face would be a better choice.

https://autode.sk/2OKQ62u

Hope it helps!

Re: Contour Surface with shaped edges

NachoShaw — Thu, 15 Nov 2018 19:24:35 GMT

Thanks for the reply. Not exactly what i am trying to achieve. Image a long length of wood 2" x 2". it needs to start from the left edge, follow the surface and terminate on the right edge. The back edge of the 2 x 2 would remain on the surface at all times.

Then, there would be a total of 7 rails that need to follow the surface all splayed equally from Left to right and following the surface.

Any other ideas?

Nacho

Re: Contour Surface with shaped edges

NachoShaw — Fri, 16 Nov 2018 03:24:16 GMT

I managed to achieve what i needed, partly thanks indirectly to your video.

I split the compounded surface into sections

added a cross plane at each split

created a sketch on each plane with the split line projected through and equally spaced the points

created a sketch on the back plane(with the split lines) and projected the points from the sketches

added a spline to each level of points (7 in total)

extruded the splines as surfaces through the compound surface

used a 3D sketch to create an intersection curve between each extruded surface and the compound surface

used the loft command between the first & last profile and used the intersection curve as the rail.

took about 10 mins to do 🙂

Re: Contour Surface with shaped edges

Xun.Zhang — Mon, 19 Nov 2018 07:46:30 GMT

Nice result! ~

Re: Contour Surface with shaped edges

johnsonshiue — Mon, 19 Nov 2018 18:36:48 GMT

Hi Nacho,

You did not attach the part here. But, based on your description, I think you are doing it a bit more complicated than necessary. There is a simpler workflow by using Ruled Surface. What you need is to get those edges split on the curvy surface. Then use Ruled Surface command to create surfaces on those split edge (direction = perpendicular to the surface). Then you can thicken the surfaces side way.

Could you try it and see if it works better?

Many thanks!

Re: Contour Surface with shaped edges

NachoShaw — Tue, 20 Nov 2018 18:01:56 GMT

not sure exactly what you mean. I have attached the model if you are able to demonstrate your method 🙂

Thanks

Re: Contour Surface with shaped edges

johnsonshiue — Wed, 21 Nov 2018 00:10:07 GMT

Hi! Here you go! It is not too difficult. Just repeat the process of splitting, creating the rule surface, and then thickening it.

Many thanks!

Re: Contour Surface with shaped edges

NachoShaw — Wed, 21 Nov 2018 16:39:49 GMT

Thanks for that. There is really any beneficial saving between how i approached and how you approached it.There are still the same amount of features with the main difference being i used a loft and you used a ruled surface & thicken. However, My version remains a single surface to each rail face whereas yours has 10 surfaces per rail face.

So, i dont think there is any right or wrong way.

Ruled SurfaceLofted

Re: Contour Surface with shaped edges

johnsonshiue — Wed, 21 Nov 2018 18:48:59 GMT

Hi! It is up to you. I believe my workflow should generate less features but I could be wrong. For stylish design like this, Loft is Ok since you are not going to dimension exactly. The issue with Loft is that the geometry is actually under-defined. Essentially, there is a lot of assumption made by the Loft command to generate such shape. You can have multiple solutions for a given input. Ruled Surface is more strict. The same input and settings only generate the same shape.

Many thanks!