Couple question about isometric drawing and fillets.

[Lurking]

I recently started drawing in cad, and i have a couple problems. At time now i am trying to learn more of isometric drawing and i have couple questions about drawing a particular figure:

 

 

So in there i don't know how to draw that "thing" witch i highlighted in red. I don't know at witch angle i should draw it's center(center length should be 50 cm). If I would know that, i could easily draw a isocircle above. So how do i find this "right" angle?

 

Second question would be about isofillets - i read here in forums that i should do them in isocircles, and i did that and i got good results - it looks very good, but the problem is, that in this drawing, it shows that those isocircles should have a defined radius - R6, R16 and etc, but if i do round corners with isocircles, i dont get that result(in R16 case radius is even way too big). So maybe there is a way to do them "right" and have them defined? I attached that drawing, would be thankful if someone helped.

[ReMark]

You are not using LT?

[ENAA]

It seems so the center it could be a slight "off-center" for the inner diameter of the isocircle, in comparison for the center for the bracket.

Maybe you could post your drawing so far?

[Lurking]

No, i use normal autocad. Okay, wait a little bit.

[JD Mather]

The red "thing" is called a rib.

 

Use offset to set center of isocircles.

I would not spend 10 minutes doing isometric 2d as it is difficult, of limited use and old school. So much easier to simply do as 3D.

[ReMark]

While there is some merit to doing this in 2D I would recommend that in the future you model similar objects in 3D and extract the various 2D views and isometrics that are required.

[iainlines]

The "thing (it's a web)" in red looks to me that is starts at 20mm up from the bottom of your part and then runs to the bottom centre of the 70mm diameter. Draw a line from the centre of the 70mm dia. then trim it to the outer edge. The start a line from 20mm up from bottom and connect the two. That should give you the centre of the web. At least in my head without drawing the part it works. Used to do a lot of iso, not so much any more

[SLW210]

The red "thing" is called a rib.

 

Actually, it is a gusset.

 

I agree just draw in 3D.

[Lurking]

The red "thing" is called a rib.

 

Use offset to set center of isocircles.

I would not spend 10 minutes doing isometric 2d as it is difficult, of limited use and old school. So much easier to simply do as 3D.

 

Can you explain a little bit more how to do it in isometric view?

 

The "thing (it's a web)" in red looks to me that is starts at 20mm up from the bottom of your part and then runs to the bottom centre of the 70mm diameter. Draw a line from the centre of the 70mm dia. then trim it to the outer edge. The start a line from 20mm up from bottom and connect the two. That should give you the centre of the web. At least in my head without drawing the part it works. Used to do a lot of iso, not so much any more

 

But how do you know where is the center of that isometric circle? Because of the view, it's center is a little bit off from platform centre, but the picture just shows that there is a 105 length differentiating from platform centre and circles centre, but you don't know where excactly (in right side) its centre should be.

 

 

So isometric view nowadays is not used at all? I actually wanted to learn 3d modeling and found a tutorial, witch started from isometric drawing and these were the exercises, so i thought maybe i should learn this very good and then after this go to 3d modeling. But thanks guys, i should probably just start straight from 3d.

[iainlines]

Though I agree with those who say draw it in 3D, as in the long run it is easier (Iso is a pain in the ass) and the right way to go about things, the OP isn't trying to do that just yet. There's nothing wrong with learning Isometric. Maybe he/she is doing this for some kind of assignment.

 

Edit: Hadn't read the OP's latest post. Appears he is doing this to learn by himself

[Lurking]

Yeah, 3d modeling is what i wanted to learn myself, because where i study all the assignments actually is plain 2d (not even isometric, but with cuts and etc).

[ReMark]

You are right, there is nothing wrong with learning how to draw a 2D isometric. It is a good skill to have when you are in the field with nothing more than a piece of paper and a pencil. This comes in very handy when tracing piping layouts.

[ReMark]

An example of an isometric view of a pillow block generated from a 3D solid model. The isometric was created using the View Base command available in AutoCAD 2012 and beyond.

[JD Mather]

In the three MCAD programs I use, SolidWorks, Autodesk Inventor and Creo Parametric (Pro/E) that feature would be created with the Rib tool.

 

 

I prefer to use the same terminology that the software uses.

I would use the term "gusset" for a supporting part in a weldment - the gusset is a part itself in an assembly of parts welded together.

[JD Mather]

So isometric view nowadays is not used at all?

 

Isometric VIEWS are used extensively - it is the process of creating that has changed.

Back on the drawing board we had no choice in technique.

Then when we first transitioned to CAD we drug along our drawing board techniques.

At some point along the line someone realized that it would be much easier to model like the real world part is made in 3D and let the software create our 2D views for us.

(read Door Into Summer by Robert Heinlein, reference to Drafting Dan)

 

Literally 10 minutes of work.

 

These are the "sketches" I started with.

 

 

Mostly simple rectangles.

Edited November 6, 2012 by JD Mather

[Lurking]

Thanks, with a couple tutorials a tried too doing this in real 3d - and it's quite easy i can say. I probably stick with 3d then, you can rotate however you want a figure so it's easier to do fillets, holes and etc. By the way, for sake of interest, how did you knew where these rectangles starts?

[JD Mather]

By the way, for sake of interest, how did you knew where these rectangles starts?

 

The width and height determines the intersection with the circle. Don't need to know the distance - it comes out in the geometry.

You might become familiar with the Parametric tab (although this geometry is easily solved without parametric constraints).

I will try to post a proof solution tomorrow but examine where I came up with the 67 and 56 dimensions in the image I posted earlier.

Edited November 8, 2012 by JD Mather

[Lurking]

Thanks for answers guys, i got it. How could i missed that, it's so simple.

[JD Mather]

Good to see you are figuring out this stuff. Usually I have to go around and around trying to explain basic geometry.