Import and use DFX or DWG format 2D sketch geometry with Inventor part

[roygoldray]

Hello,

I, ve to import DFX or DWG 2D sketch formats generated by an external online spur gear generator with these settings:

in Inventor 2019 to extrude gears. Because I've difficulty generating gears with the Inventor generator, which is described in my previous post "Generate spur gears 3:1 ratio with setting pitch diameter and number of teeth".

When I loaded DFX the first time it opened, but impossible to copy selected lines with an edit of the sketch to the new part sketch, and with the next import attempt, the DFX and DWG appear blank.

I've followed How to import DXF generated by Eagle to Inventor and Importing DXF files to Inventor as well as To Open or Import AutoCAD DWG Files as an AnyCAD Reference Model but it is empty. Here is the Import Destination Option, I've tried different settings, but can't import and use the attached files (2 versions of gear in DWG and DFX): 

The only way I have imported DWG is by creating a new part, selecting the XZ plane with adding the sketch, and File > Open > Open DWG, copying growing curve lines and pasting to sketch, but this way the scale of the sketch is different, instead of ⌀ 14 mm I got ⌀ 1167 mm diameter

[cadman777]

I use Inventor 2010, so maybe it's different in 2019?

Open your DXF in AutoCAD and select all the stuff you want to copy.

Make sure you know the UNITS it is drawn in.

RMB>'Copy to Clipboard' (2019).
Open Inventor and start a Sketch.

RMB>Paste and pick a point.

Make sure you select everything and change the COLOR b/c mine always comes in black and I can't see it.

That should do it.

Now, if you want to VERIFY all the dimensions and design, you have to add Constraints and dimensions to it.

You can even use your MachineryHandbook to verify the dimensions and design.

If you do, it may be wise to just do one tooth so you can array it or make one slice of it and array that Feature.

If not, then the original data may be a very big load on your computing power.

But if you convert everything into simple Inventor entities, you will gain a lot in that area.

One more thing. When I do gearing or sprockets, I usually represent them as a cylinder with a 'halo' (a cylindrical surface) as the PitchDiameter. And I make the chain a simple 'H' design that's Swept around a profile of chain run. That way the chain and sprockets won't drag down the computing power by keeping them simple. I would do full gears like you're doing ONLY if I'm going to get them cut and polished instead of purchased from a vendor like Martin or BostonGear.

[roygoldray]

Hello, thank you for your feedback and answer

---

I use Inventor 2010, so maybe it's different in 2019?

Open your DXF in AutoCAD and select all the stuff you want to copy.

Make sure you know the UNITS it is drawn in.

RMB>'Copy to Clipboard' (2019).
Open Inventor and start a Sketch.

RMB>Paste and pick a point.

Make sure you select everything and change the COLOR b/c mine always comes in black and I can't see it.

That should do it.

---

I did all these steps according to the first part of the guide and seems like the spur gear online generator DWG sketch is not available to copy. Also, I do not quite understand the second part where you're adding constraints and dimensions to the sketch and resizing the curve:

Now, if you want to VERIFY all the dimensions and design, you have to add Constraints and dimensions to it.

You can even use your MachineryHandbook to verify the dimensions and design.

If you do, it may be wise to just do one tooth so you can array it or make one slice of it and array that Feature.

If not, then the original data may be a very big load on your computing power.

But if you convert everything into simple Inventor entities, you will gain a lot in that area.

---

Seems like I need some explanation examples for this method:

---

One more thing. When I do gearing or sprockets, I usually represent them as a cylinder with a 'halo' (a cylindrical surface) as the PitchDiameter. And I make the chain a simple 'H' design that's Swept around a profile of chain run. That way the chain and sprockets won't drag down the computing power by keeping them simple. I would do full gears like you're doing ONLY if I'm going to get them cut and polished instead of purchased from a vendor like Martin or BostonGear.

---

[cadman777]

To get the geometry, I just unzipped your zip file and then opened the DXF in AutoCAD.

Did you try that?

If you did, and didn't see any geometry, then maybe the COLOR of the geometry is black and you can't see it.

If so, then try this in AutoCAD: Ctrl+A to select all geometry, then change the color in the Properties dialogue.

Find attached 2 examples.

'1a' is your DXF copy-and-pasted into an inventor Sketch (HUGE bog-down on the computer!).

'1b' is copy-and-paste enough for the bores and 1 tooth (much better).

'1c' is a simplified gear w/the surface as the PD (best option).

Note: I guessed at the PD b/c I don't have your gear spec.

I had to work on the tooth profiles to get them to extrude correctly.

I didn't fix them the way they should be fixed b/c they were Polylines and require a lot of time to fix.
The problem with your DXF file is that it exported from your gear generator app as a Polyline.

You may want to export it it from that app as a Spline and import it into Inventor that way.

The Polyline shows sharp edges, but the Spline will be smooth.

Exporting can be a tricky thing, depending on the app it's coming from.

[roygoldray]

I don't have AutoCAD on this computer, but with the opening part in Inventor, all the gears are in inches, and with a copy of the Project Geometry lines it is 1162 millimeters:

[cadman777]

with a copy of the Project Geometry lines it is 1162 millimeters

OK, but that's your gear OD, not PD.

I'm a bit confused about what you need to accomplish.

Your screen cap shows you have gears on the screen.

Are they inside Inventor's editor?

If so, then what are you having problems with?

Also, when I copied the geometry from AutoCAD and pasted it into Inventor, I ran into the problem that it copied twice.

So I had to delete every piece of geometry 1x to get a clean sketch.

What a PITA!

Also, when I tried doing it the easy way, the file had so much geometry that it took FOREVER for it to import.

The easy way is opening a sketch inside Inventor and invoking the Import DWG command, like you show above.

Incidentally, I NEVER use the Inventor GearGenerator, b/c is SUCKS!

Unless they improved it since 2010, I would advise against using it.
Same w/the BoltGenerator and ShaftGenerator.

Most of those 'productivity tools' SUCK.

I've only used them enough to know NOT to use them.

[roygoldray]

They are in the Import options window, which also shows some extra and random lines of geometry, and your example is opened in Inventor, but still, with the big incorrect size, the same result is if I load generated files with DWG Open or Import in Inventor. They are generated with an "evolventdesign" online spur gear generator with a 1/3 ratio, where the small 14 teeth gear is a 14 mm pitch diameter, the outer circle 16 mm, and the big 44 teeth gear is a 44 mm pitch diameter and 46 mm of outer diameter.

It seems like it is my lack of knowledge and experience with this tool because I can't find the correct setting for the required gear. I've created a few different spur gears before with Inventor Gear Generator using the Export Tooth Shape, and they are perfectly working.

Here is my close result for the required gear setup calculated without errors, but the Center Distance is too big 74.289 mm, I'm trying to reduce the size of the small pinion gear to 15-20 mm of outer diameter, or the size of the big gear, accordingly to change scale for the Center Distance and size of pair gear from Inventor Gear Generator.

[cadman777]

Why didn't you just go to Boston Gear or something like that to get your gears?

They provide 3d models you can just download.

Takes less than 5 minutes to pick each one.

Is this a special gearset that you need to make it yourself?