LOFTING / TWISTING A FLAT BAR

[Anonymous]

Hi,

I am not sure if lofting is the correct way of going about this.

I don't have a file to show you. I need to draw a flat bar 1/2 x 1/4 twisted 90 deg half way along the length.

How can I do that?

Thank you in advance

Sammy

Inventor 2014 sp2

[JDMather · Accepted solution]

Extrude the two straight sections.

Loft between the end faces to fill the gap, click on the Mapping tab of the loft command and map the correct point-to-point transistions.

Set to Tangent conditions (to the extrusions).

Attach your attempt here if you can't figure it out.

[johnsonshiue]

Hi! You can use Coil or Helical Path Sweep to do that. In R2015, you can apply Twist angle in Sweep.

Thanks!

[karthur1]

I would use the Sweep feature with Twist added like this.

Kirk

[Anonymous]

Thank you all fof the prompt reply.

I couldn't figure out the sweep thing with a twist 🙂

I'm on 2014.

Extruding 2 sections & filling the twisted portion by lofting worked fine.

Again,

I thank you all for your quick help, wow:)

Sammy

[WILLIAMF]

Old post I came across but I do  a lot of twisting of waveguide tubing.

How do you know  which way the twist is going? Clockwise or counter clockwise?

I know you can for example put 90- degree or -90 degree but some of the shop guys ask me to indicate direction as well.

It can get a little tricky

[johnsonshiue]

Hi William,

It depends which end you are looking at. If I understood how Twist Sweep worked correctly, it is like looking at profile sketch from the start and into the path progressing direction. The twist angle should be a clockwise positive value.

Many thanks!

[WILLIAMF]

Thanks for verifying that. Have a look at the attached part. A waveguide assembly with bends- a soldered flexible section and a twist of 78.39 degrees. So two separate tubes with brazed on flanges.

Clockwise or counter clockwise. I guess what I was asking if the command line could indicate either clockwise twist rotation or counterclockwise.

It was explained to me its as if you are driving into a tunnel. Imagine the car direction following the path of the twist and that is the direction of the twist.

I think what you say" It depends which end you clamp down... and the other end is twisted. These always make me stop and think...

Thanks

[johnsonshiue]

Hi William,

My comment specifically applies to Twist Sweep. If the twist was created by other features or it is on an imported body, all bets are off. Since, there isn't any information on the body to identify the twist and how the twist was created. I was merely explaining how Twist Sweep works.

Many thanks!

[WILLIAMF]

Thankyou

I agree. The solid is a Creo imported IGES. My job is to create a working drawing to produce this part.

The part has no intelligence.

[Anonymous]

.

@JDMather

@johnsonshiue

just want to add an extra degree of complexity 

Can this be done so that a Flat Pattern can be created ?

[TheCADWhisperer]

---

@Anonymous wrote:
...just want to add an extra degree of complexity 

Can this be done so that a Flat Pattern can be created ? 

---

You might investigate the Inventor Beta http://beta.autodesk.com

[johnsonshiue]

Hi Duncan,

JD is right. Currently, Inventor is not yet able to flatten non-cylindrical bend or non-developable faces. There is an alternative workflow involving the free Autodesk Mesh Mixer (meshmixer.com).

https://forums.autodesk.com/t5/inventor-forum/unfold-complex-surface/m-p/7249578#M652238

Or, you can sign up Inventor Beta and try the Unwrap workflow.

Many thanks!

[TheCADWhisperer]

If this is not just an academic question and you really need this - I have figured out a better technique than the one demonstrated in the thread that @johnsonshiue linked and can create a video of my new technique.

Attach your *.ipt file if interested.

[via05306]

Hello,

I'm trying something similar as the original poster but twisting a flat bar in the mid section with 170° angle.  Would be interested in your having look at your method.

[TheCADWhisperer]

@via05306

You should have started a new thread and included a reference link to this thread.

Attach your *.ipt file here and I will demonstrate how to generate Flat Pattern.