Angled lines

rhino

#1

I am having a lot of difficulty trying to put a draft on a model. I have a model that has perpendicular sides and I need to set a draft so the model can be demolded easily. The model is shown here. I cannot figure out how to approach this task. A 3 degree draft would work.

Model attached.

ThanksForum_frame_01.3dm (3.0 MB)


#2

I am having difficulties to see what you actually want to mould, but when you have a closed curve as the basis, you can use the Truncated Cone TCone command.


#3

Draw a rectangle around the shape in top view and use CurveBoolean to create an outline of the entire thing. Tidy up the result and extend/trim any curves.

Offset the close curve and then loft between the top edges of your shape and the curve you’ve just made.

Quick and dirty like…

Andy


#4

Thank you Andy. I will try this tonight.
Matthew


#5

In essence you’re creating the outline in plan at the base and top of the part. Once you have the outlines of the drafted shape you want I would rebuild the curves with fewer control points. Try to have the same number of control points for the curves at the base and curves which make up the top face.

Rather than lofting everything at once you can break it up into faces for lofting:

Once you have the main part you can then Wirecut/Trim or Boolean bits away to get your final model.

Good luck!


#6

Thanks. I have found the best way to create the surfaces is Sweep With 2. In actual fact I need to draft sides 2, 3, 4, and 7. The part you see is a section of an array. 1 joins into 6. I am going to try Andy’s suggestiion which if I understand correctly will lock the curves into a frame. The problem I see here now is that for example, the point between 1 and 2 will not draft at the same rate as mid way along 2, by this technique. Could extending the curves to create the offset be a solution? I am not sure how to measure or exact the draft.
Thanks
Matthew


#7

Looking at the curves I can’t quite work out what it is you need to develop.

(ignore that it’s the PC version you can follow the same steps)

Here’s a quick (long winded!) video of how I’d get to a basic shape using what you’ve presented. From there you should be able to cut stuff away or build upon it.

http://screencast-o-matic.com/watch/cbhb6DXyWp

Sometimes it’s too much to ask of the program to do everything in one hit - you get more control if you do it in steps - it also gives you insight into how you could approach the problem in the future.

I hope that helps. Apologies if it’s nowhere near what you’re looking for :slight_smile:

Andy

Forum_frame_02.3dm (117.7 KB)


#8

Hi @2DCube,
What command are you using at 1:55-2:00 (after the Sweep1 rail) when the structure of the surface seemed to become simplified? Or was it an option to the Sweep command?

Edit: Ah, now I see, it was only a preview that changed into the final surface.

// Rolf


#9

Hi Rolf,

It was Simplesweep:

Andy