Creating 3D frame smartly

[s2105398]

Dear all,

since I got such excellent advice on here recently, I was wondering whether someone could help me out creating a 3D frame like shown in the screenshot 1. I have currently created a 2D frame like shown in screenshot 2. There are probably multiple ways of doing this, but before messing up the basis of my project I was hoping somebody could suggest the smartest way of doing this. Options I came up with were 3D sketch or design the bottom layer and then connect both somehow with vertical bars.

Thank you so much,

Lalit

[swalton · Accepted solution]

I don't usually bother with frame generator, so my workflows may not be the best.  I usually find it easier just to stick-build the frame from scratch.  I usually don't know what I want the frame to look like before I start the design effort.

When I use frame generator, I tend to make a "frame sketch" part.  In that part I create a series of 2d sketches and workplanes to define the frame centerlines.  It takes some thought and planning to build my frame sketches before I start frame generator.  I want to include critical dimensions and define the reference geometry in a way that will allow me to modify the frame in the future. I may or may not constrain components in higher-level assemblies to the frame part.  Think about motor mounting plates, anchor pads on columns, or other items that will be attached to the weldment.

I place frame members on the sketch lines as necessary.  I try to use a single line to a member, so I don't end up with 6 different ipt files for a 2x2x2 1/4" angle, 12" long.  My company wants a single part detailed on a single idw, with a unique part number/file name that matches our standard.  Pulling 6 part numbers and creating 6 idws for the same geometry is not smart. I like to use component patterns or the repeat member command to minimize the number of individual ipt files to build the frame.

[cadman777 · Accepted solution]

For a frame like the 2nd pic, I would use FG.

@swalton pretty much nailed it.

I hardly use 3d sketches since they have a tendency to go out of whack down-stream when things change near the end of a project. So almost all my work w/FG is done using 2d sketches on WorkPlanes. I try to use the least amount of WorkPlanes and sketches as possible, esp. on a big frame, in which case I usually divide it into sub-assemblies.

Any custom platework I make with non-FG parts and appropriately constrain, or Derive the frame sketch into the part and use it as a reference so the part can be grounded to the origin of the assembly.

If you're slick about it, you can add wires (sketch lines) to a plane that isn't on the right plane for a member, and then offset the member to get it where you need it to go.

If there are small stray parts that would require a lot of WorkPlanes and sketches, I usually make them all in a 3d sketch at the very end of the wireframe part and connect them to existing geometry. That saves a lot of extra WorkPlanes and sketches. Also, I try to limit the FG to parts that don't have assembly features, such as holes and cuts. That's what happens with stairs and railings. I'll make the stairs stringers and platform from custom parts, and the railings with FG. Makes it easier to detail and to locate and plan the railing geometry.

Now if you detail every part, then you have to make provision for that using ViewReps (or now I believe you use ModelStates). Then you have to make provision for drawing PartsLists and detail views with the labels. So it can get involved if you have a lot of detailing to do. This is where you do your planning ahead of time if possible, which determines how you structure the project.

There are many ways to do this, but since your pic2 frame is simple, the quickest is probably using FG. The more experience you have, the more versatile you become with how you make frames.

[Gabriel_Watson · Accepted solution]

Great advice from the replies above.

I would just add that if you have not worked much with Inventor and wish to do this the fastest and simplest way possible, a 3D sketch for FG works well in this particular frame, given how most elements are 90deg to each other. Just abuse the "parallel with .." for axes:
 

The trick is adding dimensions and keeping it all properly constrained, which you have to check by dragging end points of the lines. I made a mockup in Inventor 2022.2 to illustrate things for you (see attached), but there is still lots of work on weldments and frame trimming/joints to be done:

P.S.: reuse frames whenever possible, if you introduce new frames after the first frame creation.

[s2105398]

Why are you guys so helpful?? This experience is fast-tracking my learning more than I ever thought was even possible. Thank you!

[SBix26]

In addition to the good advice given above, don't forget that frame members can be attached to things other than sketch lines.  Point-to-point is possible, and the edges of surface and solid bodies are available.

I typically start a frame skeleton with a surface body or two.  I can then use the edges to place members, and the faces for sketches to define more members.  Here's a sample:

I prefer surface bodies over solid bodies simply because they are transparent by default.  It's also helpful that they have no mass, I suppose, since the layout part is included in the assembly.

---

Sam B

Inventor Pro 2022.2 | Windows 10 Home 21H2