Loft between two rectangles with horizontal and vertical guides

ludwig_göbkes

Hello,
I'm pretty new to 3D modelling and after some months with freecad switched to onshape to design a Ender3 Fanduct (3D printing).
Currenlty I'm stuck while creating the Duct for the parts cooling fan.

I need to create a cutout to let the air flow to the "target".

I named the top cutout where the fan blowes the air in and the outlet where it should blow out onto the printed part
now i need a smooth transition in the vertical axis and an offset in the horizontal axis so that the air will travel out straight of the fan duct.

If I select my two surfaces and click loft than add guides and continuity and select the guides I created I always get the message: "Could not generate valid guides from selection" and others.
Can please someone help me out or explain to me why its not working. The document is here: https://cad.onshape.com/documents/6953f1a750ac373194a40d06/w/10d744094054381e9400bcbf/e/59fb429edb4006e1f129d481
The Sketches I want to loft are:
DuctTopCut
DuctBotOutlet
The guides are:
DuctVerticalGuide
DuctSidewaysGuideL
DuctSidewaysGuideR

I Spent hours searching for a solution which I still cant find. Thats so frustrating


Hope someone can help me. Thanks in advance.

MichaelPascoe

Looks like your off to a great start! Welcome to the forums.

Your guide sketches are positioned nicely with pretty good constraints. However, loft guides need to be attached directly to the vertices they are guiding in 3d.

Here is one approach you could take to do this:

• Create a top sketch and a side sketch (similar to what you have done) with lines or splines connecting each vertex that is to be connected from one profile to the other.
• Use the Projected curve feature with the side guides and their matching top guides to created 3d curves that connect your vertices.
• Loft the two profiles together with the new 3d guides. (Notice how this method did not turn out well. I took another approach by lofting the sides first as surfaces, then lofting the surfaces together. This made for a cleaner looking loft in this case.)
• Finally you can use the Boolean feature to remove one part from another, or while your lofting you can switch to "remove" instead of "new" loft.

Don't forget to check out the self paced courses in the Onshape learning center for other great tips and best practices.

https://cad.onshape.com/documents/01ab47d8fea50dd5f2b93679/w/b62f4d1c6c681393835ada28/e/7f819e5b44d26b4e1543b038

MichaelPascoe

Sure thing!

MichaelPascoe

Looks like your off to a great start! Welcome to the forums.

Your guide sketches are positioned nicely with pretty good constraints. However, loft guides need to be attached directly to the vertices they are guiding in 3d.

Here is one approach you could take to do this:

• Create a top sketch and a side sketch (similar to what you have done) with lines or splines connecting each vertex that is to be connected from one profile to the other.
• Use the Projected curve feature with the side guides and their matching top guides to created 3d curves that connect your vertices.
• Loft the two profiles together with the new 3d guides. (Notice how this method did not turn out well. I took another approach by lofting the sides first as surfaces, then lofting the surfaces together. This made for a cleaner looking loft in this case.)
• Finally you can use the Boolean feature to remove one part from another, or while your lofting you can switch to "remove" instead of "new" loft.

Don't forget to check out the self paced courses in the Onshape learning center for other great tips and best practices.

https://cad.onshape.com/documents/01ab47d8fea50dd5f2b93679/w/b62f4d1c6c681393835ada28/e/7f819e5b44d26b4e1543b038

ludwig_göbkes

Wow thank you sooooo much.
I have been struggling the whole weekend with this.
Now I can go on with it.
Thank you soooo much.
You made my day

MichaelPascoe

Sure thing!