3D cad design sequence

[Gordon]

I keep finding different ways to do things than the way I did them. The same was true when I started using my 2D cad 25+ years ago. The problem is I will probably not remember all of this stuff the next time I use it. I am not using it on a continual basis. I mostly make some drawings and then make the parts. That means that it is probably going to be weeks before I use the program again. At my age I have trouble remembering what I had for lunch. I am 82 so I only have another 18 years to work with it.

 

[Richard Hed]

I keep finding different ways to do things than the way I did them. The same was true when I started using my 2D cad 25+ years ago. The problem is I will probably not remember all of this stuff the next time I use it. I am not using it on a continual basis. I mostly make some drawings and then make the parts. That means that it is probably going to be weeks before I use the program again. At my age I have trouble remembering what I had for lunch. I am 82 so I only have another 18 years to work with it.

Yes, that's what I found--When I went thru the tutroriAls again, I found things I had forgotten which were very useful. But so what? Just go thru the tutorials again. Did you try some Chineswe herbs for your memory? they can help.

 

[GreenTwin]

That is why I make screencaptures of every step.
2 years later I have complete mememory of what I did, via the screencaps.

I am no spring chicken any more, but there are ways to circumvent the memory thing.......leave a paper trail.

.

 

[johnmcc69]

Again, probably by design. How would SW know which point in your ACAD sketch should be connected to the SW sketch origin? I think what you mean is SW ignores your ACAD origin so it temporarily appears to float? Until you provide it some requisite information to align & anchor to its universe (which is trivial to do). Actually makes perfect sense to me. SW is doing you a favor. Remember SW a 3D modeler which means a sketch plane is not limited to the 3 primary XYZ based planes. Planes can be orientated at any angle in 3D space, however you define it. Furthermore as my prior example tried to show, the planes may well change & update if they are based on underlying features which have changed, which is exactly what you want. Anyway lets say you are in SW about to sketch on one of these seemingly random angled planes, how could SW guess the origin of your 2D model? They are apples & oranges. This is another side effect of how you've chosen to work, not a SW program limitation. Not sure but I cant image this would be different in any other 3D modeler. I suppose it could guess the origin & lock it down, but if it guessed wrong, now what?

By way of analogy, when you import a background jpeg into SW to act as a basis for a design, SW doesn't know how many pixels equals an inch or mm or if the picture is the side/top/bottom/cross section. How could it? So first you specify the correct plane & import. Now it does provides a useful tool. Upon importation it pops up a distinct reference line which you can re-orient & slide grips to reference positions & dimension the line. Now the background grid is essentially dimensionally scaled to the picture, which means any subsequent sketching you do (tracing features) automatically has a corresponding dimension that makes sense relative to the jpeg.

.I've decided to move this topic here, out of my 2D CAD thread.

@petertha: When I import a sketch into Pro-E (& this is not a sketch created in ACAD or else ware, but totally in Pro-E)), it gives me options as to scaling & placement. I can select an orgin or (X0Y0Z0), & put it exactly on the 3D location I want it.

As an example, I have quite a generic sketch of a "Hexagonal" section, when I'm in my sketcher I can import this into my sketcher, & because it was PROPERLY constrained, I can insert it at any scale & location I want. IE: in insert the sketch & it prompts me for a location, by selecting a point, I also set the scale factor at the same time.

I would be willing to bet that you can save a sketch right out of your own 3D CAD program & re-use them.

JoHn

 

[petertha]

When I import a sketch into Pro-E (& this is not a sketch created in ACAD or else ware, but totally in Pro-E)), it gives me options as to scaling & placement. I can select an orgin or (X0Y0Z0), & put it exactly on the 3D location I want it.

Looks like SW does much the same. This link & videos shows the SW import wizard & many related available settings, including defining an origin. I guess if you skip defining the origin it will appear to have been plopped in there randomly. I know you can also copy-paste as a shortcut which likely may not offer the same control vs the wizard. Maybe that's the source of confusion.

https://www.javelin-tech.com/blog/2...rks-reference-sketches-from-2d-dxf-dwg-files/


https://www.solidsolutions.co.uk/solidworks-videos/importing-a-dwg-or-dxf-file-into-SOLIDWORKS.aspx

 

[Jasonb]

It's the same with Alibre too, if I want to copy a sketch used for one part and place it for use in another I get two options.

1. Pastes it in exactly the same location relative to where it was constrained (positioned) in the original.

2. All parts of the sketch can me moved around the screen as one and placed where I want. They don't retain the original position constraint but do still have all their constraints relative to other items that make up that sketch.

 

[David Shealey]

--------------------------------Snipped-------------------------------------------

I have never used constraints on any engine I have modeled.
I am told I MUST have constraints, but I don't use them, and have never had a use for them.

I have used 3D modeling for about 20 years professionally, and do not understand how you do assemblies without constraining/mating! Just having one or two missing constraints (or mates) in an assembly can cause real issues for me.

 

[GreenTwin]

We have a Tower of Babel going, and nobody is using consistent definitions of anything.

Assemblies in SW use "mates".
I use mates.

There is no way to discuss our way out of this topic.
Everybody has their own terms, and everyone applies them differently.

I have done my best to explain this topic, but I am definitely bailing on this because we are getting nowhere with the conversation.

I am out of time for any further discussions about 2D or 3D.

.

 

[Gordon]

Still progressing on this. I have found dozens of ways to no do things. I get something that I think is correct and then I try to do something with it and find that I have built in conflicts. Turning on notifications for conflicts has helped so that I know immediately that I have a problem. Just because it looks right does not mean that it is right. Constraining a part to a surface instead of concentric means that it will not rotate. I have found out that inserting a part and then rotating it causes all kind of problems. Better to get it in proper orientation before I start moving it around. I am having a problem figuring out how to align parts with an axis or plane. I am presently experimenting with importing cad drawings from another source. Presently trying to work on some spur gears. Keep notes.

 

[Jasonb]

Gordon. if you wnat to align a part with a plane one way is to right click the part and select "show reference Geometry" thsi will then show the 3 planes you constructed the part with in brown. Then fairly easy to click one of the main green planes and one of the brown ones of the part and use whatever constraint you need. Right click again to turn off the parts ref geometry.

 

[Gordon]

I have downloaded the 3D drawings from the vendor site. I then opened the 3D drawing and it loads but I cannot do anything with it. There is no way to edit a sketch. Sketches and extrusions are not imported. Perhaps I should download a DWG or DXF and then work on that. Part of the problem may be that I am working with Atom3D and it does seem to be missing some things. Holes to make different screw configurations for instance. Obvious there are going to be differences between the $150 program and $1000 program.

 

[Jasonb]

Gordon, can you post a link to what you downloaded

See if you can download and open this part of mine frame.AD_PRT

 

[Gordon]

I can open your file but this forum will not allow me to download sldprt files. Got the file from Rush Gears. I tried importing DWG but it will not let me make a drawing because there are too many conflicting points.

https://www.rushgears.com/tech-tools/part-search/build-custom-gears

 

[Jasonb]

download the gears as a 3D STEP file and then open it with Atom.

 

[Gordon]

This is what happens when I first project to sketch and then try to extrude. Then I get this:

9003: The sketch cannot be used because an endpoint is wrongly shared by multiple primitives or has overlapped figures.

 

[Jasonb]

Not sure why it won't work for you, this is one imported as a STEP, using project to sketch I get the sketch of the gear profile and can then extrude that sketch

Another way to make the gear wider would be to use "scale/mirror" and select "non uniform" the enter the percentage increase for one axis

 

[Gordon]

Not sure what the problem may be but when I extrude it extrudes the bore but not the gear teeth in spite of showing both teeth and bore. I am not able to delete the bore. I am about ready to call it a week. It will still be there next week. Not sure how awake I will be on Monday. We switch to daylight saving time so we lose an hour of sleep.

 

[awake]

Gordon, hopefully you gained an hour of sleep ...

 

[Gordon]

Gordon, hopefully you gained an hour of sleep ...

This time change thing really throws me off. The clock says 7 AM but my body knows that it is actually 8 AM. Takes me at least a week to get my body to accept the change. I handle the losing an hour much better.

 

[awake]

I don't handle either transition very well. I would be happy if they would go ahead and let us stay with "daylight savings time" all the time ...