problem of maintaining a volume during a loft

problem of maintaining a volume during a loft

Anonymous
Not applicable
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14 Replies
Message 1 of 15

problem of maintaining a volume during a loft

Anonymous
Not applicable

Hello everyone,

i'm troubling with a design. I'm making a rail in with a guide must pass. The problem is that the space in with the guide is supposed to go is not the same all allong my trajectory. I have a about 2 or 3mm error and i don't understand why...

 

thank you for your help é_è

 

rail_haut.PNGrail_face.PNGrail_biais.PNG

kelly.young has embedded your images for clarity.

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Accepted solutions (1)
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14 Replies
Replies (14)
Message 2 of 15

TheCADWhisperer
Consultant
Consultant

@Anonymous wrote:

... i don't understand why...


Can you attach your *.ipt file here?

(I suspect Loft is not the tool I will use to fix the geometry.)

Message 3 of 15

johnsonshiue
Community Manager
Community Manager

Hi! Like JD said, it is better to attach an example here so forum experts can comment further. Did you use Center Rail option in Loft? If the start and end profiles are proportional, I would use guide rail Sweep instead. Please attach the file here.

Many thanks!



Johnson Shiue (johnson.shiue@autodesk.com)
Software Test Engineer
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Message 4 of 15

Anonymous
Not applicable

this is the .ipt !

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Message 5 of 15

Anonymous
Not applicable

i'm struggling with the upload of the .ipt... it dosen't work when i try to upload it in my reply 😕

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Message 6 of 15

Anonymous
Not applicable

@johnsonshiue: I can't use sweep because of the mouvement I want to create. I tried to use sweep before but the joint between two sweep was not acceptable. And I tried with trajectory and guides rails, it's the same problem...

 

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Message 7 of 15

SBix26
Consultant
Consultant

The ability to attach .ipt files is temporarily (I hope!) unavailable.  Zip the file and attach it.


Sam B
Inventor Pro 2019.0.1 | Windows 7 SP1
LinkedIn

Message 8 of 15

Anonymous
Not applicable

this is (for real) the .ipt

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Message 9 of 15

TheCADWhisperer
Consultant
Consultant

Can you Attach zip rather than rar?

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Message 10 of 15

Anonymous
Not applicable

sure

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Message 11 of 15

TheCADWhisperer
Consultant
Consultant

I'll try one more time.

No third party software needed.

Only your Windows Operating System - 

 

How to zip a file with Windows OSHow to zip a file with Windows OS

Attach the resulting *.zip file here.

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Message 12 of 15

kelly.young
Autodesk Support
Autodesk Support

Hello @Anonymous I've reattached your file as .zip here for others to inspect. 

 

It appears you are using 2012 so attaching my attempt won't help you much, but would recommend making sure your sketches are Fully Constrained and investigate using Sketch Blocks to define your shape so that you can easily use it in other sketches, just have to copy and paste.

  

SketchBlock.png

 

In your case you would also have to mirror but using the block makes it much easier and controllable. That way you will only have to locate it in space with the 15° and 15mm dimensions. 

 

Setting up a sketch in the middle could help drive the shape more accurately if you want to stick with Loft, but using Guide Rail Sweep would be best as stated prior. 

 MidSketch.png

 

Please select the Accept as Solution button if a post solves your issue or answers your question.

Message 13 of 15

johnsonshiue
Community Manager
Community Manager
Accepted solution

Hi! Many thanks for sharing the 2012 part! If I understood the design intent correctly, I do not believe you would get the desirable result by using Loft. The reason why Loft may not work for this case is about the section orientation and twisting. Loft does not offer any profile orientation or twisting control. As long as the loft face pass both sections and follow the rail reasonably, it is considered a solution.

I have a question regarding the 3D Sketch Trajectory. It looks like a 2D arc and positioned in 3D space. Shouldn't it be a helix instead? The reason why I am asking is that I still believe Guide Surface Sweep is what you need. However, the path is not reasonable. It creates awkward profile orientation no matter what Guide Surface I choose.

Many thanks!

 



Johnson Shiue (johnson.shiue@autodesk.com)
Software Test Engineer
Message 14 of 15

Anonymous
Not applicable

Yeah, it's not an helix i need, it's this design exactly but without faultess in dimensions... therefore, I changed all my piece since this way was a dead end. Thanks for your help

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Message 15 of 15

Anonymous
Not applicable

thank you for those advices, I didn't knew all these details. Nevertheless, I tried to fully constrained my 2 sketches but no difference was there, so I did not pay attention to the .ipt I shared ... My bad ^^

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