Drawing Board & Beyond - Again

Transcription

1 Drawing Board & Beyond - Again December 2007 Craig Snell Craig has used Autodesk software all of his working life starting with AutoCAD R12 16 years ago at Nissan Motor Manufacturing UK Ltd. Now working at Imass Ltd, the UK s number 1 manufacturing reseller, his position of Senior Training Consultant leads him to all areas of the UK to clients with many different industries. Craig spends most of his working week teaching Autodesk Inventor or AutoCAD, but also teaches AutoCAD Mechanical and Autodesk Viz, and is a member of the UK ATC Advisory Board. Craig is married with two daughters, and spends his spare time with his family, watching Newcastle United and playing badminton. I don t know if you read my last article, which was about 3D annoying me. You should read it s a good article. It s not what you think I actually love 3D, but its people s lack of understanding of 3D that annoys me. That s me off my soapbox now; I ll get on with this article. In this issue of the infamous beyond the drawing border (it s only famous in my own mind, but that is good enough for me) I want to talk about a certain feature of Autodesk Inventor, namely the frame generator. I ve been using PC s and CAD systems in general since I was small, shy 16 year old starting working at a big car factory. Ever since then and for ever more you get additions to products, upgrades or new releases whatever you would like to call them, whether this is for AutoCAD or Inventor or be it Microsoft Office or the Sims, they get better year after year. I have been in the training / reseller industry for many years now, and every year new features appear in the products, now when they do appear it s my job to learn them, and pass the information on to my clients. I always think when I m doing this, that Joe Bloggs Inc could use X feature, and Bob Trollop ltd round the corner can use Y feature. The Frame generator in Autodesk Inventor is different, 99% of Inventor users can use it, whether you make furniture, widgets or big industrial machinery, to be honest I think it has been marketed slightly wrong, in the past it has been marketed has steel frame design but it is so much more, and if you carry on reading you will learn why!!! The Frame Generator You can use the frame generator in 2 simple ways, either by placing frames on an existing sketch or by creating an envelope and placing the frames on the edges. You can even bring in existing 2D AutoCAD data to use as your sketches; we will have a look at this way first. Drawing Board & Beyond_Again Craig Snell 1/16

2 Our scenario here is that we make trailers, the kind you buy to fit to your car, when you have bought too much stuff from IKEA, something like the attached photo. So we have been in this business for a while now, but historically we have been using AutoCAD to produce the drawings for the shop floor. So here is a very basic drawing of the kind of the thing, which you would give to the shop floor. Obviously the people on the shop floor would struggle making the trailer from the drawing above, so you would normally do a few other views, and maybe if you are clever even an isometric view. Still they would need more information to build the trailer such as cutting list. Now we are going to start using the frame generator to help us do this. One of the hidden features of Inventor is the ability to cut and paste directly into a sketch, it s been around for a few releases now, but a lot of experienced Inventor users do not know that the function exists. I ll do it now, and show you the results. Drawing Board & Beyond_Again Craig Snell 2/16

3 That s it, simply by cutting and pasting you now have a parametric Inventor sketch, Inventor also recognises the AutoCAD dimensions and turns those into Inventor ones, so by changing the number it will change the sketch, no more drawing accurately!!! OK, we have the basis that we will use to create our frame, Its quite simple really, save the part file, and insert it into an assembly file, no more no less, you don t have to extrude or revolve the sketches just leave it as it is. When you have created your assembly file, with the part file in at the top of the browser click where it says assembly panel, and change it to the frame generator. Next comes the hard part, (difficult in text, but that was fully laden with sarcasm). Your Panel bar will change, as it does when you change from sketch to features etc, and it will look like this. Drawing Board & Beyond_Again Craig Snell 3/16

4 Simply press the insert button, and the following box will appear. In this box you will find your normal standards, such as ISO, ANSI and DIN, and you will also find loads of different types of beams, such as solid round and square, hollow frames and I-Beams and many more. In this example I have picked a Hot Rolled Flat beam, you can also change the justification and rotation. From this point just click on the various elements of your sketch to add the frames to your assembly. After you have picked the edges (you can also do this between points if you want to), Inventor will prompt you to save an assembly file. Inventor is asking you to save a sub assembly so you get your entire frame in one file rather than having lots of individual members. You can change the filename if you want. After accepting the sub-assembly naming, Inventor will also ask you what the naming structure will be for all of the individual members, you are able to rename these files. Drawing Board & Beyond_Again Craig Snell 4/16

5 Inventor will now create the framework for you, as the following picture shows. There a few problems with this frame such as the edges don t meet, and some notches will need cut, and frames trimmed and extended, but we will look at that bit later on. In the following illustration, I have simply added a metal plate on the top of the frame, using create component, and I have also added a couple of wheels (from the Inventor Samples), you could obviously carry on, and add the axles and hitch etc, but I ll carry on without doing that. As I mentioned before, there are 2 different ways of using the frame generator, we will now have a look at the second option. The second option works by creating an envelope that will become the basis of your frame, such as building, conservatory or even decking for your back garden. Drawing Board & Beyond_Again Craig Snell 5/16

6 Starting in an Inventor IPT file, I have created my skeletal model (that is term you will hear more of in the future years of inventor). It is just a basic shape, the internal void where my frame will be. You could even go a step further, and add extra sketches onto your shape, that will allow you later to add frames to these sketches. So for the next step, again it is very similar to what we did before. Start a new assembly, and place in the part file you previously created, then save your file. Now switch to the frame generator just as we did before. Drawing Board & Beyond_Again Craig Snell 6/16

7 In this example I will use a simple square section frame which is 60 X 60mm; all I need to do is pick the edges where I want the frames to go. In the following picture you will see a preview of the places where your frames will be. Within the same box, you could change the frame members and apply them to different edges. Drawing Board & Beyond_Again Craig Snell 7/16

8 After you are happy with your preview, press OK in the dialogue box, you will then be prompted to save a sub assembly, followed by the naming convention for the individual frame members. Drawing Board & Beyond_Again Craig Snell 8/16

9 Here is the model with the frames attached to it. Now if you turn the visibility off on the base model, you will see your frame in all its glory. Now there are some other tools that you can use in the frame generator, such as mitre, and trim extend, we will have a look at a few of these tools. Drawing Board & Beyond_Again Craig Snell 9/16

10 If you take this corner here, this would probably require two different end treatments. The first one would be a mitre Simply pick the mitre, the following box will then appear. Pick your two frame members that you want to mitre (in this case the bottom members) Press OK and Inventor will finish the corner for you. To finish the corner properly, we will need to trim the vertical frame so it finishes at the mitred corner. Drawing Board & Beyond_Again Craig Snell 10/16

11 Press the Trim Extend to face button, although we are using this to trim the frame, it can also be used to extend. In the following box, pick the frame member you would like to trim or extend (blue button), and then pick the face you would like to trim or extend to (yellow button) You now have a nicely finished off corner! We will have a look at one more end treatment, before we move ahead and that is the notch command. The notch command cuts away a portion of a frame, where it intersects, very much like the normal extrude command, but it is a lot easier than the extrude tool, because there is no need to project geometry. If you look at the image below, you can see the frame intersects each other, so using the notch command we can sort that out. Drawing Board & Beyond_Again Craig Snell 11/16

12 After pressing the notch button the following box will appear, which allows you to select your frame members. The blue frame member (first selection) is the frame that you want the notch cut out of. The second selection (yellow frame member) is the frame that is going to be used as the cut geometry. After you have pressed OK, this will be the finished result, and one of the frames will have a notch cut away from it, as shown. So that s it, that is the frame generator, it s very easy to use and you get very impressive results with very little work. There are a couple of other things I would like to show you before I depart, so here goes. Drawing Board & Beyond_Again Craig Snell 12/16

13 Cutting Lists When you are doing frame like this, whether they are made from wood, steel or plastic, they will require a cutting list, basically a table on your drawing showing what lengths each frame is. Now if you are doing this sort of thing in AutoCAD, it is painful, it takes a very, very long time. If you are using the frame generator in Inventor it does it for you. To show this process I will jump back to our first frame. So in the following picture, there is a quick drawing of our full assembly. So I will create another sheet, and just show the frame, please bear in mind, that I am not actually doing anything complicated here, everything is all set up straight out of the box, it just a few clicks of a few buttons. Simply by pressing the parts list button, I can put in a cutting list, and then using the auto balloon tool, I can balloon the drawing, and here is the finished article, and I honestly pressed 2 buttons, that s all! Drawing Board & Beyond_Again Craig Snell 13/16

14 Last thing I would like to discuss is not an in-built function of Inventor, it's an add-on, but the best thing is it is free. You can get from there is loads of good free stuff, Autodesk tend to use it as a testing ground, to see if customers want the features, there has been things that have graduated from there to being bona fide products such as Autodesk Impression. Back to the frame generator, at the Autodesk labs you can download the frame customisation tool, this simple but very powerful application allows you to create your own customised profiles, and get them added to the standard frame generator library. I am not going to go in to too much detail here, as the readme files you get when you download the application are excellent, but you basically draw the profile that you want (it is better to do this with parameters) add that profile to the frame generator, and then using excel you add the sizes in that you want. If you look at the images below there are couple of customised frame I have added in So as you can see, there is another standard which I have called CRAIG. Now you will get all of your customised frames, as shown overleaf. Drawing Board & Beyond_Again Craig Snell 14/16

15 Then just as you did before simply add the frames by clicking on the edges of your space frame. Drawing Board & Beyond_Again Craig Snell 15/16

16 Well that is all from me from the moment, I hope you enjoyed my article, and I hope to write another soon, I have no idea what it will be about (suggestions more than welcome), but if you have any questions or comments about this please feel free to drop me a line Craig Snell Board of Directors Craig.snell@augi.com Drawing Board & Beyond_Again Craig Snell 16/16