Machined flats on threaded rod

[Anonymous]

Threads aren't difficult at all, but they do not allow common modifications found on parts I need to model. For instance, a threaded rod with machined flats or flutes in the threaded portion of the rod, holes drilled through threads, keyways machined into threaded rods. These are all things commonly found in aviation parts to be modeled.

Has anyone experienced these kinds of parts and figured out how to model them accurately? I can think of hundreds of examples of parts that have threads that are machined into and modified. The world of aviation doesn't come down to bolts with perfect threads, they often get modified with countersinks, keyways, flutes, flats, holes, etc. And if you are able to model this in Inventor, I'd like to know how you are doing it.

Thanks!

[Mark.Lancaster]

@Anonymous

First thing, modeling threads in Inventor will impact Inventor performance. So does the actual threads need to be modeled?  Secondly adding the features you're asking for, seem to be a simple process so I have to ask what are you struggling with?  Can you provide any example of what you have done and not been able to finish because of these extra features?  Also what Inventor version are you using?

[Anonymous]

Inventor Pro 2016 version.

Seems like a simple thing to want to put machined features into a threaded part, but it is not!

[johnsonshiue]

Hi! Custom thread usually needs to be modeled by using helical sweep (or coil). Sometimes surface modeling can help make it easier. Modeling such geometry should not be an issue. However, helical sweep faces (thread) are quite complicated. Representing it properly in graphics requires finer faceting which can add to graphical load. The geometry itself can be heavy too.

Could you provide an example of the parts with such thread you are trying to model? Forum experts should be able to propose good workflows.

Many thanks!

[PaulMunford · Accepted solution]

The way you've modelled you part gives you two separate bodies - is this intentional?

To cut through both bodies, you need to select them both in the Extrude dialog.

I've attached a Screencast, let me know if it helps?

Paul

http://autode.sk/2F7MaVa

[TheCADWhisperer]

I would model this part essentially the same way that I would make it out on the shop floor.

In the 3D CAD realm, these should be very very easy to model (easier than making out on the shop floor).

I notice that several of your sketches are not fully defined - this is bound to cause issues, especially with iPart.

First thing I do out on the shop floor is establish an absolute datum.

[mcgyvr]

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@Anonymous wrote:

Inventor Pro 2016 version.

Seems like a simple thing to want to put machined features into a threaded part, but it is not!

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It is a simple process..

As asked already...Is there a reason why you "need" to physically model the threads or would the out of the box cosmetic representation of them be sufficient?

edit.. Just noticed Paul posted a simple video showing how to cut through multiple solids...

[The_Angry_Elf]

Not sure why you are modeling the actual threads, especially if they are not custom threads.

I'd simply create the part to size and add the graphical thread representation as you already have in the part.

Then either make the required cuts or model in the cuts and then do the thread application.

The specifications of the thread are embedded so when you detail them on the drawing, you'll get the specs spelled out as needed.

[Anonymous]

Having the threads modeled is intentional as it allows multiple variations of threads for the same basic part. A lot of turnbuckles have both left and right hand threads for example.

Anyway, the need for true profile threads is real. I think if people are making fasteners, using the cosmetic threads can work fine. Almost nothing I model can use cosmetic threads, and that's why they get modeled separately.

Thanks so much for your help on this!

[PaulMunford]

You might find this App helpful?

'The threadModeler tool has been developed to allow  Autodesk® Inventor®  users to generate a realistic modeled equivalent thread based on an existing Inventor thread feature. Users are able to select an existing thread feature in the model, which the threadModeler then converts to a realistic 3D modeled thread based on the underlying thread feature properties.

Modeled threads are accurately generated saving a lot of time and effort for the user when compared with a manual approach, bringing a higher degree of realism to your models.'

https://apps.autodesk.com/INVNTOR/en/Detail/Index?id=2540506896683021779

[mcgyvr]

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@Anonymous wrote:

Having the threads modeled is intentional as it allows multiple variations of threads for the same basic part. A lot of turnbuckles have both left and right hand threads for example.

Anyway, the need for true profile threads is real. I think if people are making fasteners, using the cosmetic threads can work fine. Almost nothing I model can use cosmetic threads, and that's why they get modeled separately.

Thanks so much for your help on this!

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Nothing written there is a reason you must model the actual threads..

One can easily have both left and right threads using cosmetic representations in a single part.