[Rance]

Guys (& Gals),

I've been Xpress'ing in the evenings and am getting my head around this CAD thing. Since the free one does not come with a parts library, that is one of my first tasks. I've built a bolt or two, a nut, a T-nut, along with some router-specific parts. I started this thread as a possible venu to discuss parts-design but more importantly, to SHARE OUR PARTS. I'll post what I have as soon as I fix a couple of problems I have with the ones I've already created.

In making bolts, I've tried to add threads but am unable to get the 'OK' on the dialog to be enabled. That tells me I'm not providing all the necessary info, etc. for Alibre to add the threads. Any insight here would help.

Also, In building a parts lib., for a given bolt size (1/4-20 for instance) do I have to make several parts, one for each length I'll be using? Thanks for your relentless help.

[spalm]

Rance,

I believe that Xpress only allows 25 components in an assembly. We are going to have to be creative to avoid this problem. One of the first things to go is bolts. Or another way to look at it is to make major components as a single component. Then in a separate assembly, define how to make it. Take a torsion box for example. The major assembly will contain a solid box to keep the component count low, then a separate assembly that will describe how to make this box. This is a major bummer, but does the job.

We will need bolts in the end. IMHO I don’t care if the threads show on a bolt. They can always be added later to make it pretty. But yes, length does matter. You can left click on the Extrude (in the left hand window) and select edit, and then change the length. Change this to common values while saving to descriptive file names to get a complete set.

Steve

[Rance]

Steve,

Yep, you're right. Look here to find some more detail about inserting sub-assemblies to get around the 25 part limit. I agree w/you on the bolt threads. And even for the bolts, I think for building an assembly, just use one long bolt for everything for alignment purposes (if needed), then delete them before saving the assy.

One BIG problem I'm having is with the angle iron that the bearings are bolted to. When I design it, looking at the XY axis, it looks like an 'L'. That's not it's natural orientation when inserting it into an assembly so I end up needing to rotate it A LOT. I got close one time trying to rotate it correctly but basically have been unsuccessful. I even tried 'Precise Constraint' but the Angle part of it only seems to work intermittantly for me. I'm sure its just that a noob doesn't understand Xpress well enough but I've not been successful. I have all the parts built for the bearing assembly except for the angle iron. Actually, I have one built but I need to rebuild it to orient the 'Z' axis perpendicular to what I currently have, and rotated 45 degrees. I may have to enlist you to create the angle iron part for me. LOL

Rance

PS: I already have this all drawn up on graph paper. You don't know how close I am to just shooting a pic of that with a camera and posting that. :nono:

[ger21]

Rance,

I believe that Xpress only allows 25 components in an assembly.

I think that's only for the first 100K that signed up. Anyone after that only gets 5.

[spalm]

Yikes,
5 is really small. Seems like you can play games to trick it. But yuk.

[Rance]

Well, I just tested mine and the limit on my installation is 10. :frown: Not 5, but certainly a far cry from 25. Maybe I was the 99985th user.

[dannyboysd89]

If you are one of the first 100K you can import files from a CAD Library, sounds like some of you may not be. I use www.ohyeahcad.com, I have the Alibre Expert, and they have gotton away from the add-on part library in the last coiple of months and went t o a mess of an online library. I can not find a thing so I use ohyeacad. This library is exactly what used to be the add-on for Alibre. try it out and explore it, you can all sorts of fasteners and even angle iron is there.

Dan

[ger21]

Well, I just tested mine and the limit on my installation is 10. :frown: Not 5, but certainly a far cry from 25. Maybe I was the 99985th user.

More like 100,001 unfortunately. If you have 10, then I must have been mistaken. I am somewhere around 48,000, but have neot tried to build an assembly yet.

[spalm]

DannyBoy, thanks for the link. While poking around there I noticed TurboCad V11 for $125. Gerry weigh in here. It seems that this is an AutoCad type of system. I am really bummed with the restrictions from Alibre. I just want (for now) to do assemblies like the attached pdf that I did in Inventor. I want to buy my own system to use to build assemblies. Going to CAM is another story, but everyone seems to have dxf output. I really liked Inventor’s interface (but way to large and expensive) and Alibre’s seemed about the same. I don’t get the same feel from my copy of AutoCad Light, I can not even design a torsion box in it. The pdf shows (to me at least) that I am not totally CAD illiterate. What is it, what am I missing? What do I call the kind of CAD that has the click and shoot interface of Inventor and Alibre (and I think SolidWorks)?

Not feeling good about this,
Steve

[Rance]

Gerry,

I was figuring that the first user could insert 100,000 parts, and the 99,999th user could only insert 1. Seriously, I'm doubtful that I can live with only 10 parts.

DannyBoy,

Just from looking at the home pg. it looks GREAT. Thanks for the link.

Another viable alternative that might just work is 'Blender 3D'. And the best feature is that it is FREE. Blender is a GNU freeware pkg that a lot of Linux folks use for generating characters & animation. At first I didn't give it much thought but you can run it on a PC too, you don't need Linux. Steve, did I mention that it was FREE? I was introduced to Blender only 2 days ago and sent my son after it for some of his interests so I don't know much about it yet. However, it 'could' be another possiblility for our CAD drafting needs. Steve, did I mention that it was FREE? I have to go back to work now but I'll try to check it out more this evening. Oh, one more thing Steve, did I mention that it was FREE? BTW 'Free' is not a four letter word, it is just after 'Two'.

Rance

PS: Oh, and there are SEVERAL tutorials out there too.

www.Blender3d.org

[ger21]

What is it, what am I missing? What do I call the kind of CAD that has the click and shoot interface of Inventor and Alibre (and I think SolidWorks)?

Not feeling good about this,
Steve

There are 2 basic types of CAD programs. Parametric Solid Modelers (Alibre, Inventor, Solidworks, .....) and then "old style" CAD, which mostly started as 2D CAD and then 3D options were added along the way.

These two types of CAD programs function in completely different ways. If you learned on one type, switching to the other can be difficult. I use AutoCAD everyday, and while I can probably model anything I want in Alibre, it would take me a long time to figure out how to do it. Modeling in AutoCAD is easy for me. For you it's probably the other way around.

It sounds like you'd prefer the parametric type. I'f the only restrictions you don't like about Xpress is the assembly limit, I'd but the $199 assembly expansion. Even at full price ($1295?) Alibre (full version) is the cheapest out there.

Using TurboCAD (I prefer DesignCAD), you can build the same models, but not parametricallly. You can't go back and change a dimension and have the whole model change. You'd have to redo averything affected by that change. There are no constraints or anything like that. It's a completely different system/

The benefit of a 2D type system, is you can quickly draw toolpath .dxf's and export them. Then use something like SheetCAM, you'll have the ability to cut probably any part on your machine with just a 2D drawing. There's no need for the 3D model.

A system like Alibre, on the other hand, can be more difficult to get basic 2 1/2D machining from. SheetCAM won't load 3D models, so you'll need a much more expensive CAM program to derive 2 1/2D machining from a 3D model. There might be easy ways that I'm not aware of though.

It all comes down to how much do you want to spend, and what type of system do you want.

Btw, you can download demos of both DesignCAD and TurboCAD from www.imsisoft.com

[ger21]

Rance, I can almost gaurantee you that you'll find Blender has a pretty steep learning curve. I've never used it, but have a little 3D animation background. If you want to model characters and organic shaped objects, check out Silo at www.nevercenter.com There's a free (apparently your favorite word ) learning version, and the full version is onl $109.

[Rance]

... free (apparently your favorite word ...

Yep, Steve's too I think. And sometimes we get what we pay for.

I don't mind a steep learning curve, however, from what you described, going from Blender to G-Code may have some of the same drawbacks that Alibre will have. In that sense, Blender may not be any better of a solution.

Rance

[ger21]

Blender would be fine for doing 3D work with something like MeshCAM. But most hobbiest use 2D .dxf to g-code programs, like ACE (free ) or SheetCAM. For that type of work, 2D CAD is all that's needed.

Another option is to draw your 2D .dxf's in an inexpensive CAD program, like TurboCNC, DesignCAD, or even A9CAD (free again), and copy and paste into your sketches in Xpress to create your 3D models.

[ger21]

More free stuff.

http://www.wings3d.com/
http://www.anim8or.com/main/index.html
http://www.4dblue.com/home.html

[ger21]

Steve, rereading your post, you said you can't design a torsion box in AutoCAD LT. Do you mean 3D? AutoCAD LT doesn't do 3D.

[Rance]

Gerry,

So a Parametric Solid Modeler is one where you can change the dimension of one part and others adjust automagically? Is Xpress a PSM?

I'm guessing that using a 3D modeler (with or without PSM) might be nice for designing your machine for building purposes but modeling a 2D part to be cut would be better off done on something else. Am I catching on?

Rance

[ger21]

Gerry,
So a Parametric Solid Modeler is one where you can change the dimension of one part and others adjust automagically? Is Xpress a PSM?

Yes, and yes.

I'm guessing that using a 3D modeler (with or without PSM) might be nice for designing your machine for building purposes but modeling a 2D part to be cut would be better off done on something else. Am I catching on?

Rance

It depends. A good CAM program, say something like Visual Mill, can take the 3D part from Xpress and create the 2 1/2D g-code to cut it. The problem is that there are no inexpensive CAM programs that can do it. MeshCAM creates 3D g-code, which is not ideal for most machine parts.

So for hobbiests, the best way is usually 2D .dxf files. I don't know if you can get 2D .dxf's from Xpress, or if they would work correctly.

Does this make sense?

[Rance]

Yep, and Yep.

Steve says everyone's Xpress seems to have dxf output. And Yep, it's starting to make sense. Thanks.

[spalm]

Thanks Gerry. Good explanation. I get it. Paying for limitation removal from Alibre sounds like it might work for me. Right now I want to play with assemblies so I really want this kind of system. I did some test parts, saved them as dxf drawings, and loaded them into AceConvert with no problems. It was really painless.

I don’t mind paying a reasonable amount of money for software although I would rather not if I don’t have to. I was actually thinking more of the users of this site which really need to save a nickel but they are probably not modeling machines. Alibre’s free offer is still a good buy.

Steve