Learning to use CAD

[Cedge]

Thank you MM.... It is indeed computer generated. There are slightly more than 3500 individual components in that project, with all the proper bits programmed to be animated, if I ever manage to get a computer that can take the pressure. The technique is called "Ray Tracing" and computes the reaction to light on the various surfaces.

Steve

 

[steamer]

Hello Cedge!


Wonderful work! Thanks for sharing that!

I was thinking about documenting the creation of a part or two using Alibre for the benefit of those trying to learn.

What do you think?

Dave

 

[Brian Rupnow]

Cedge--Those are stunningly beautifull renderings. The CAD I use is strictly utilitarian, not a lot of art to it. I know that there are "photo rendering" add on packages for use with Solidworks, but in my line of work they don't "buy the groceries". I know that the Solidworks software I use for machine design also has "packages" (which of course can all be added at an additional cost) for mold makers, sculptors, artists, etcetera. I wouldn't begin to know how to turn out anything as gorgeous as the pics you posted.---Brian

 

[CrewCab]

Steve, those are "works of art"............ are you sure you ain't just downloaded them ........ : ................ just kidding mate ......... honest 8)

I remember the term "Ray Tracing" from a couple of computer guru's I came across ........ back in the 80's I think, never took it any further mi'self ....... but it seemed quite time consuming ............. or have I lost the plot ........... again ???


Just to try and date this, .......... and for no particular reason except I'm bored ........... : ................ I believe a 486 DX-2 66MHZ Computer was "State of the Art" back then and "Mr Pentium" ........... was just about to knock on the door


How times change .................. ??? ............. and very quickly

CC

 

[Hilmar]

If "YOU ALL" would like me to show you something regarding that I could, but I will wait to be asked

Just this afternoon I Drew an expansion link in Turbo Cad. Noting big in 2D.
Then I tried to expand it to 3D, tried to give it height.It worked OK but some of the curves turned in to straight lines. So I give up! Back to 2D only.
Himar

 

[CrewCab]

Back to 2D only.

You n' me both mate ................ 2D I can cope with .............. 3D ... Oh eck

CC

 

[zeusrekning]

Well I reckon I post an opinion too. I use solidworks. Absolutely love it. I wish I had the fancy imaging addition. But I think the elitism griping is a bunch of ****. If someone wants to detail the use of anything related to model engineering so be it. And please do tell us what it cost. It is a real close call with me ,as far as satisfying my desire to create, to own machinery or a really nice cad package. I just acquired machinery at home a few months back. But I've had SW for a few years now. There are a lot fewer limitations to what I can create in SW than what I can in my shop. If someone goes out and buys a wire EDM I hope they don't feel they can not post about it in fear of being elitist. Cause there are things and EDM can do that can only be done on on one. I get so sick of people whining about HSS vs Carbide, Cad vs pencil and paper, Manual vs CNC, Import vs Domestic. Buy what you want do what you want. But keep in mind most of us spend a fair amount on machinery and tools to make toys. This would seem to most that have not been bit by the bug as very ignorant. I thoroughly enjoy reading about equipment, materials, methods, and tooling I'm not familiar with.
Tim

 

[steamer]

Hi,

I have had a couple of requests, I will try.

A couple of points. As I may not have thought this through as far as I should have.... :-[ :

I use Alibre. I can't vouch that it works the same as Cadkey or Turbocad, or Rhino or whatever your using.

Differant software have differant operating styles. I will do my best, your mileage may vary

I posted this reamer on another thread.

Its a simple part. Heres how I did it. There are 473000 ways of doing it, but I chose this

Step one
I drew a sketch of the reamer body, a circle the correct size for the reamer. In this case 0.500"

I then extruded that circle to 5 inches long. In Alibre that is a default length, but it can be what ever you want, just type it in.

Next I made the tapered part of the reamer. To do that I formed a body of revolution or Revolve Boss command.
I drew half of the cone from the centerline out, and then using the Revolve boss command on the tool bar, rotated the sketch to create a conical boss. A pointed end. You can see the outline of the sketch in the picture.

Next I made the D cut. This is D/2 + .003 for D bits. This was done again with a sketch, but instead of adding geometry, I used a sketch to cut some off ( the sketch was nothing more than a rectangle)
Think of it as a giant form cutter hacking off half of the end...

I then used the fillet function to put a fillet at the corner of the previous cut, This is to reduce the stress concentration at that point in the D bit.

I have no idea if this is going to work for people, so if it isn't working...just say so...

Hope that helps some....

Dave

 

[zeusrekning]

Would work the same in solidworks. Like you said one of the many ways to do it.

 

[steamer]

Hi seusrekning,

I am fluent in Solidworks 2001 ( old!). Solidworks and Alibre have a very close "style" I did my boat in Solidworks and was able to accurately determine the center of gravity, the center of boyancy, and many other hard to compute attributes. Alibre isn't as polished as Solidworks, which I love dearly, but man it packs alot of bang for the price.

Could of done the whole thing as revovled boss.... 8)

Regards,

Dave

 

[zeusrekning]

I'm far from fluent. There is so much I still have not learned. It annoys me often b/c I feel like there is surely an easier way to complete my task. But hopefully I'll get a little more formal training on it one day. SW is very decieving b/c of how user friendly it is. I'll have to check into alibre too.

 

[BAH101]

That could also be a TurboCAD tutorial. Done the exact same way. Turbocad also has a cylinder tool, so you could form a cylinder instead of extruding from a circle.
Bryan

 

[steamer]

Well..perhaps this effort will be helpful then.....time will tell

 

[steamer]

Hi Bryan,

"That could also be a TurboCAD tutorial. Done the exact same way. Turbocad also has a cylinder tool, so you could form a cylinder instead of extruding from a circle.
Bryan"

Yes, that would be , generally speaking, a Bolean. Alibre has that feature also. I was trying to start with a 2D sketch for the sake of those normally dealing with a drawing, Bog Cad or otherwise. If you can make what your thinking about, it goes a bit easier.....

Dave

 

[Maryak]

Brian Rupnow,

Well whadyaknow! - followed your little gem about one bit at a time and at first was like 10 bits at a time NBG.

Read some more of the idiots guide to Turbocad and Eureka the keyword for me in 3D turbocad is WORKPLANES, just like it was layers in 2D.

And you are absolutely 110% spot on, one at a time and slowly slowly catchim monkey. I am pretty chuffed ;D

Nothing achieved that I want to put up against some of the wonderful efforts in this post, but thanks to you at least I'm up and crawling, not just laying there dead beat. :big: :big: :big: :bow: :bow: :bow:

View attachment 3droof.pdf

 

[steamer]

Good for you!

Dave

 

[Brian Rupnow]

Way to go Maryak!!! Congratulations. Yes, I'm not sure how other 3D programs work, but with Solidworks there are 3 default planes, Front, top, and Right. These planes all intersect at the Origin. When you are going to start making a "part", you must first select which "Plane" you are going to start your 2D sketch on. Then you make the sketch on that plane, and when you are finished the 'sketch', then you can "extrude" it. I always start my sketches on the "front" plane, to make my first extruded part. Then if I want to add something to that part at 90 degrees to the original plane of extrusion, I can select one of the other 2 remaining planes.--Solidworks also gives you the option of creating your own "plane" either on an existing surface that you have created, offset from a surface you have created, or at an angle to a surface you have created, OR to any of the 3 existing default planes. It also lets you start a "sketch" on the "face" of something that you have already created. You only really need to start your very FIRST sketch on one of the default "planes". The very first part that you make MUST be an extruded 'boss or base" to actually get a part made. After it is made, you can then start a sketch on one of the other default planes or on the side of the "part" which you have created and use the "extruded cut" command to drive a specific shape hole (cut) either through the part completely, or to a depth which you specify.

 

[Loose nut]

Once you get a little experience you don't have to draw individual parts, you can work within an "assembly" of parts that make up your project (assuming that there is more them one part). You create a work plain on an existing surface ,see Brian's explanation, and then the new sketch can use points on the older part as a reference. The previous parts in an assembly usually "fade out" so they aren't in the way of the new part being made. Hard to explain with out visuals and over the net.

The easiest way to understand 3D is not to think of it as drawing, the program does all that for you when your model is done, but it is more like virtual sculpting. You are building a virtual part or assembly which fits together just like they were in the real world, usually better then the real world. The hard part is making the real parts to the same level of accuracy that the program can draw them. It's easy to model things that are pretty much impossible to make.

 

[Brian Rupnow]

Once you get a little experience you don't have to draw individual parts, you can work within an "assembly" of parts that make up your project (assuming that there is more them one part). You create a work plain on an existing surface ,see Brian's explanation, and then the new sketch can use points on the older part as a reference. The previous parts in an assembly usually "fade out" so they aren't in the way of the new part being made. Hard to explain with out visuals and over the net.

The easiest way to understand 3D is not to think of it as drawing, the program does all that for you when your model is done, but it is more like virtual sculpting. You are building a virtual part or assembly which fits together just like they were in the real world, usually better then the real world. The hard part is making the real parts to the same level of accuracy that the program can draw them. It's easy to model things that are pretty much impossible to make.

Loose Nut--Which CAD program are you using? In Solidworks, everything goes back to the "Part" level. Yes, when you become an advanced modeler, you can create "in context" parts in an assembly, and reference existing geometry, but the part thus created is still saved as a "part" file. However, I stress, this is for ADVANCED modelers, not someone who is just being introduced to 3D.

 

[Brian Rupnow]

I tried my Expansion Link again. Got the lines straighten out but the rendering is not working out. I will ad an attachment .
#1 starting out OK in 2D
#2 gave Height in 3D and wireframe
#3 render but only the slot should be white looks this has no top or buttom

Hilmar

Hilmar---The .PDF sheet is blank.---Brian