Import ACAD File As Sheet Metal

[Quagga]

You need to learn about constraining sketches, or JD will be all over you, like a bad suit!!!!! But otherwise good job so far. I had the same problems moving from AutoCAD to Inventor in release 4. Just got to remember it's not like AutoCAD at all.

 

Cheers

 

Al

[Bill Tillman]

You need to learn about constraining sketches, or JD will be all over you, like a bad suit!!!!! But otherwise good job so far. I had the same problems moving from AutoCAD to Inventor in release 4. Just got to remember it's not like AutoCAD at all.

 

Cheers

 

Al

 

That's what I'm dreading...the wrath of JD....

 

And considering I've never used Inventor until less than 48 hours ago and I slept at least 16 hours of that....I am making progress... But it's hard to comprehend why I can get the model (the corrected version) into Inventor and it all looks fine. I can see the planes and flanges, edges, etc... but then when I clicked on Flat Pattern View it just rotated the model and showed me an orthographic view that has nothing to do with flat panel. I have attached this latest Inventor file so at least JD won't have to rebuild it all for me.

Cosmetic Cover Plate(05).zip

[rdharvey]

Wooo alot has gone on in this thread since Friday! would try take it further for you but i am running 2011 so can't use your 2012 file

 

Sounds like you are learning though! & doing well as you go....

 

Constraints are easy and make sense when you get your head round them - its just good practice to get used to used them to your advantage.

 

Hope you manage to get your model sorted! if there is anything i can do to help the nfeel free to ask!

[Bill Tillman]

I tried to save the file to 2011 format but unlike AutoCAD it does not seem to have that functionality. So I save the AutoCAD 2011 file and attach it here. I hope this puts it into a format you can import in your version of Inventor.

 

I have the constraints thing sorted out. When I get confused on why I can't change a line I just view all constraints and then I can see where my problem is. So that's working out.

 

I am so used to drawing in AutoCAD and when I try to sketch in Inventor I don't seem to have the hang of getting a line to go in the Z axis. I have learned to use planes and start sketches on faces which solves the problem, but when I'm in a certain sketch and suddenly need to create a line which traverses the Z axis I can't get there.

 

I examined and studied the model provided by Quagga. His advice has been very helpful. And as I studied the methods he used to create the model I was able to understand it, but like JD, I think he went about it the hard way. For example, when I created this model in AutoCAD I just made the major sections through the part located at the correct locations and used LOFT. A few SOLIDEDIT, SUBTRACT and SLICE actions and in less than 10 minutes I had the model in it's correct final form, sans the relief notches that might be needed for a sheet metal layout. When I tried to build it this way in Inventor I got all confused again so I still have some more studying to do.

 

Thanks again and any advice you can offer will be appreciated.

Cosmetic Cover Plate(05).dwg

[JD Mather]

ADDITIONAL UPDATE: I went back into AutoCAD 2011 and using LOFT was able to get the model corrected.

 

I'm sorry that I haven't had time to post solutions, but in AutoCAD or Inventor I think I would do this as a Lofted Surface (or two), trim as needed and then Thicken.

 

The surface body and Thicken commands are slick ways of using standard tools to make sheet metal parts. There is also a Lofted Flange tool in Inventor Sheet Metal, but I have to find some time to experiment to decide exactly which technique would be the easiest (I'm quite sure it could be made far far easier than the previous posted example.)

 

Make sure you take a look at these tips and tricks http://home.pct.edu/~jmather/skillsusa%20university.pdf an hour here will save you countless hours of frustration.

[Bill Tillman]

Thanks to all for the valuable replies. JD don't sweat it, I'm sure you've got bigger fish to fry and besides I feel confident that I can get this done. Let me ask a few questions on the method I'm trying to acheive this.

 

In AutoCAD I drew four (4) different sections which I PEDIT'ed to form a closed polygon. Remember I did not REGION these because if you do when you perform the LOFT the bottom surface will end up looking like a ship's hull rather than a brake shape. The four sections consisted of one for each end and two at the transition between the high side and the low side of the model. I positioned these at the correct offset from each other, the two in the middle being coplanar. I then LOFT'ed the two tall sections and then LOFT'ed the two short sections and then UNIONED them together. Then I added the flat unbent surface on the front end of the model. The holes were then a mere fomality and the model now seems correct and complete. But when I imported it into Inventor is would not unfold. I think this has something to do with the thickness in Inventor's sheet metal properties matching the thickness in the AutoCAD model's thickness, which it did not. So I created a new sheet metal type with the same thickness (.125"). This time when I tried to unfold it in Inventor, instead of giving me a pattern which looked nothing like the unfolded version, it came up with an error dialog box which said it was unable to do the ASMFlatPattern. I did some googles on this but found nothing appropriate thus far.

 

That said, I am now trying this method to get the model created totally in Inventor. Unlike the AutoCAD model I think the best way to do this is to create the bottom surface, then split it into three sections, then add flanges with the correct leg distances to the edges. I have tried to draw the sections like I did in AutoCAD but then trying the LOFT only got me to a point where I got very confused again. Still have lot's to learn about Inventor especially how to LOFT and more so how to get lines in one sketch to constrain to lines in another sketch. So here's what I'm trying...

 

While in the Sheet Metal Mode, I create a sketch which outlines the bottom surface of the model. I then extrude the bottom to .125" and then offset a few planes at the transitional locations in the model. I then try to split the solid on these work planes but I cannot split it because as far as Inventor is concerned I don't have a solid even though I have extruded the sketch. So I try this again using Standard Part and do the same process with the planes and this time I'm able to split the solid into the three parts I need. But then when I tell it to convert to Sheet Metal so I can add the flanges it tells me I cannot do this unless I remove the Multiple Bodies....

 

Alas, so close yet so far!

[Bill Tillman]

More break throughs to report.

 

1. The process of building the folded model in Inventor is proving elusive for me until I learn some more skills with how to get the sketches to interact for the LOFT method which I think would be the simplest method.
   
2. The method I tried of outlining the bottom surface, then SPLIT it into several parts has also proved elusive. But I think if you could get this to work it would involve addding many folds that it would not be as simple as the LOFT method above.
   
3. I finally tried the old, "Reverse Engineering" method and just sketched out what I believe would be the finished flat panel layout and then applied folds. Funny thing about FOLD is that when you choose to FOLD in lieu of BEND, you are asked to select the BEND lines....just to be silly I guess. I also discovered that if you layout several BEND lines in a sketch and then you FOLD along one of these lines, the other BEND lines will disappear. I guess this is due to my next point...
   
4. When you make a FOLD, the part may and probably will change orientation to the orginal X-Y-Z axis. I thought I constrained this original sketch fully but now that the model is finished I don't have it on an axis which I can easily select the top view and see what would be considered a correct orthographic view to provide to the CNC guys. This is another skill I need to learn about how to realign the completed model with the XYZ axis I want. Again something I can easily do in AutoCAD but need to find the information for Inventor.
   

The model, while finished, I'm sure will be judged as sloppy. I need to put some dimensions on it now to check that the correct dimensions are in place. And again, I still need to find a way to LOFT the finished shape and then let Inventor take care of the sheet metal layout. This is the only way I will have confidence that I can quickly layout something and get an accurate drawing which can be sent to a fabricator.

 

Learning Inventor is a brutal process. The docs are often lacking and like so many things in life, the authors of the docs proceed in a direction I don't want to go and too many times they only describe enough steps to get a new user in trouble assuming that everyone knows as much about it as they do and fill the video with totally uneccesary information and erratic mouse movements. Sheeesh! It's enough to drive a man to drink.

 

JD - The link to your PDF file with tips proved very useful. Thanks.

[kencaz]

Trying to model by making the flat pattern first will get you in trouble. Inventor is designed to help make this process easier.

 

Inventor makes it simple with a few strategically placed cuts extrusions and mirrors.

 

 

As long as you stick with Inventors sheet metal rules you wont run into to much trouble getting your flat pattern.

 

 

Yes, Inventor is not easy to learn right away. But once you get past the basics you can advance pretty quickly.

 

Good Luck

 

KC

[Bill Tillman]

I agree. Making the flat panel layout did not get everything correct. But what it did do was finally give me a model that I could get into AutoCAD. I made the adjustments to correct the dimensions there, because and only because I know how to do this in AutoCAD still not sure how to do this in Inventor. Anyway, once I saved the 3D model in AutoCAD I was able to import it back into in Inventor and yes it did work properly this time. The flat panel layout came out correct. So I am still having to learn the finer side of Inventor.

 

Can you tell me how you made this model? Did you layout the bottom surface and start from there? I have had some success with that method but I was thinking that the LOFT method would be more efficient but I just can't seem to get the sketch right to do the LOFT with Inventor. Could you possibly upload your Inventor file so I could study how you prepared this model?

 

Thanks again to everyone for the advice and tips.

[kencaz]

Can you tell me how you made this model? Did you layout the bottom surface and start from there? I have had some success with that method but I was thinking that the LOFT method would be more efficient but I just can't seem to get the sketch right to do the LOFT with Inventor. Could you possibly upload your Inventor file so I could study how you prepared this model?

 

Thanks again to everyone for the advice and tips.

 

Yes I started with the bottom surface, (New Sheet Metal Part). Then flanged the sides up. Cut the flange to make the step and mirrored the whole feature to the other side.

 

I'll upload the file when I get home tonight...

 

KC

[Bill Tillman]

After studying till all hours, getting my daughter through her graduation, going on job interviews and shaking off a bad cold, I think I finally got this one nailed, with a few exceptions which I could use some expert advice on.

 

Thanks to kencaz for confirming with me his method of starting off with the bottom surface of the model. I tried to LOFT but this method is still something I need more study on with Inventor. And I think the bottom first method was actually the most efficient.

 

The other thing I discovered was that by using the offset method when I was adding the vertical flange, it quickly resolved the problem I was having with the bottom surface being cut off or misshaped with a radius at the wide opened end.

 

So in a nutshell, I created the bottom, added the flange on one edge using offset, then did a cut to get the different heights for the horizontal flanges. I then added the flanges to the tops of the vertical legs and once again, the notch needed at the transition was taken care of by Inventor, which is a good thing. The holes were added and then I simply mirrored this work to the other side.

 

The only problem is with the edges of the flanges which you will see in the attached PDF file. I tried doing a Move Face but this turned out to be rather difficult and didn't give me what I wanted. The flanges at the very top have enough material for me to split off but when I use the XZ plane as the split tool it slices off part of the vertical legs as well which I don't think the fabricators will actually do nor agree with.

 

Any advice going forward with these last two points would be appreciated. Thanks again for everyone's help. I think I can confidently say that I know 10,000% more than I knew just last Friday when I opened Inventor for the first time.

Part3.pdf

[Bill Tillman]

I got got the trimming (Split) part down and have the two upper horizontal flanges now halfway there. But getting the other two surfaces to extend out the proper dimension is still eluding me. It appears in the flat panel I could make these changes but then it doesn't appear in the 3D folded model. These last two surfaces are all that appears left to get the model and the flat panel into it's final form.

 

I was able to get the additional extensions done in AutoCAD but I'd like to have an Inventor solution for this.