topic Re: Modelling Threads in Inventor Forum

Modelling Threads

anthonyserridge — Thu, 27 Jul 2023 14:50:56 GMT

Hi all,

I am an engineering lecturer and I will be teaching CAD again thith coming year and was wondering if there is an inbuilt way to model treads in inventor as opposed to having to go to fusion. I have found over the last year fusion is less user friendly for students (and myself having learnt on inventor years ago).

If there isn't a way to do it without 3rd party add ons why not? It surely must not just be me who finds this to be the main failing of inventor.

Re: Modelling Threads

Gabriel_Watson — Thu, 27 Jul 2023 15:22:37 GMT

Use this free add-on:
https://apps.autodesk.com/INVNTOR/en/Detail/Index?id=2540506896683021779&appLang=en&os=Win64

Re: Modelling Threads

CGBenner — Thu, 27 Jul 2023 15:33:53 GMT

@anthonyserridge

Direct modeling of threads is still not present in Inventor. It has been requested a few times over the years, you can see some of the Ideas HERE by doing a search on "threads". Vote for your favorites! Good luck!

Re: Modelling Threads

LT.Rusty — Thu, 27 Jul 2023 16:28:04 GMT

@anthonyserridge wrote:

It surely must not just be me who finds this to be the main failing of inventor.

Why is it a failing? What's the actual advantage of having threads present on the solid model, other than burning up extra CPU and GPU cycles to calculate and display? The way it shows now is pretty much ideal for doing drawings or for machined parts: the hole size that's shown is more or less the tap drill size for 100% threads.

Re: Modelling Threads

CGBenner — Thu, 27 Jul 2023 17:39:47 GMT

@LT.Rusty

Modeled threads are required for 3D Printing more than anything else. Printers cannot read the thread data from Inventor's cosmetic threads.

Re: Modelling Threads

LT.Rusty — Thu, 27 Jul 2023 18:03:25 GMT

@CGBenner wrote:

@LT.Rusty

Modeled threads are required for 3D Printing more than anything else. Printers cannot read the thread data from Inventor's cosmetic threads.

I know about printed threads. However, absent some extremely expensive hardware, printed threads are almost worthless except as demonstrations of how much time you spent to calibrate your printer. (For reference- at one point I had my setup dialed in well enough to print functional 85% threads at 1/2-28.) Just the variations in filament from one roll to the next can take functional threads and make them unusable on the next print.

Thing is, they're weak. If you put actual real-world torque on them, they'll generally just tear out, and tolerance stackup issues have a nasty habit of forcing your threads to be so loose that there's hardly any engagement if you want off-the-shelf fasteners to work.

Applications that really benefit from functional threads generally get designed to have brass threaded inserts that get heat-set, or there's a pocket for a nut or something else, rather than having printed threads.

Re: Modelling Threads

johnsonshiue — Thu, 27 Jul 2023 23:14:21 GMT

Hi! On top of what experts already mentioned, the proper way to create such thread geometry is to use Solid Sweep, which mimic the thread cutting process much closer.

Another option is to use Fusion 360. It does have the ability to turn on the physical thread in the Hole feature. Also it has more extensive support for 3D printing workflows.

Many thanks!

Re: Modelling Threads

Rich-T — Mon, 31 Jul 2023 01:00:27 GMT

Good points 'johnsonshiue' but why doesn't inventor have this functionality built in? Swapping between software platforms is a PITA and is not efficient.

I get the feeling that Autodesk isn't interested because they've already done it for F360 - so why should we bother with plugging it into Inventor?

Re: Modelling Threads

mslosar — Mon, 31 Jul 2023 14:30:27 GMT

For them to consider adding it, you'd have to give a benefit for them doing so.

I can't think of reason to use them short of 3D printing. Even with printing, as pointed at earlier, you spend a ton of time getting them to properly work with your printing set up. I got bolts to work, but never nuts. I wound up pulling nuts from the shop to use on the printed bolts 🙂

Re: Modelling Threads

LT.Rusty — Mon, 31 Jul 2023 15:55:20 GMT

@Rich-T wrote:

Good points 'johnsonshiue' but why doesn't inventor have this functionality built in? Swapping between software platforms is a PITA and is not efficient.

I get the feeling that Autodesk isn't interested because they've already done it for F360 - so why should we bother with plugging it into Inventor?

Again: what purpose would it serve to have the threads modeled in Inventor? I'm still uncertain of what the purpose is in Fusion, tbh.

Any threads that you're going to 3D print, you're almost certainly going to be modeling those from scratch to get your clearances and tolerances correct if you want them to work. Other manufacturing processes, you don't need a visual representation there, and all you're doing is loading down the system with unnecessarily flashy graphics. It's certainly not going to help your FEA and dynamic simulation to have all those extra non-planar surfaces to figure out.

Re: Modelling Threads

JDMather — Mon, 31 Jul 2023 16:19:40 GMT

@anthonyserridge wrote:

Hi all,

I am an engineering lecturer and I will be teaching CAD ...

@anthonyserridge

It is my opinion that every student should know how to model 3D threads if for no other reason than to gain an understanding of thread nomenclature and geometry.

Having cut thousands of threads on the shop floor in my early years - Solid Sweep is not required to create the correct geometry.

(371) 3D Printable Threads in Autodesk Inventor - YouTube

Also, I have successfully 3D Printed threads on higher end ($30k+) printers.

Other approaches outlined in >>this thread<< Message 4 and 5.

Re: Modelling Threads

SBix26 — Mon, 31 Jul 2023 20:57:23 GMT

Echoing everything that @JDMather said!

There is one exception, though, to the difficulty in modeling functional threads for 3D printing, and that is when printing in metal. While printed metal parts are not (yet) as strong as machined, they are much stronger than printed plastic, and resolution is much better also.

Sam B

Inventor Pro 2024.1 | Windows 10 Home 22H2

Re: Modelling Threads

LT.Rusty — Mon, 31 Jul 2023 21:04:26 GMT

@SBix26 wrote:

Echoing everything that @JDMather said!

There is one exception, though, to the difficulty in modeling functional threads for 3D printing, and that is when printing in metal. While printed metal parts are not (yet) as strong as machined, they are much stronger than printed plastic, and resolution is much better also.

Sam B

Inventor Pro 2024.1 | Windows 10 Home 22H2

When the finances start getting to the point where a metal printer looks like it might be around the same cost as my own private tropical island and an army of mercenaries... that's when I might start to look at modeled threads as being a need.