topic Re: Sheet metal bending radius rules. in Fusion Design, Validate & Document Forum

Sheet metal bending radius rules.

CLmoss — Fri, 03 Mar 2017 21:55:31 GMT

How does Fusion 360 handle sheet metal bending rules, like radius. Is it up to me to state or are there suggestions.. or what? I am building a 19" 3U (5.25" high) rack mount enclosure. I am about done with the front panel. So now it is on to the cage or actual enclosure with bends and PEM nuts. This will be made with 1/16" aluminum sheet. It might be 6061 or 5052 of some T or another. I will be designing the top and sides with CE standard air slots. I know what I want as I have build a model out of 1/8" without bends using my compound miter saw, table saw and drill press. Since there few bends on the model I thought I would check in here to see if there are any videos on doing this which would explain things like radius, etc. I know Solidworks does.

Just thought I would float that out there.

And Yes, it would be nice to have a flat metal function in Fusion 360 about now.

Jim

Re: Sheet metal bending radius rules.

TrippyLighting — Fri, 03 Mar 2017 23:11:13 GMT

Sheetmetal has been rolled out to some as preview function and hopefully we don't have to wait too long for it to be released to everyone.

Re: Sheet metal bending radius rules.

CLmoss — Fri, 03 Mar 2017 23:18:32 GMT

Well, does that mean I cannot create boxes or enclosures with what is there in Fusion right now and spec radius of bends? The sheet metal shops will tell me what they would like. Can you NOT bend sheet metal in Fusion?

Re: Sheet metal bending radius rules.

TrippyLighting — Sat, 04 Mar 2017 02:53:35 GMT

No, at least not currently with a sheetmetal functionality similar to Solid Works.

Re: Sheet metal bending radius rules.

TheCADWhisperer — Sat, 04 Mar 2017 12:36:07 GMT

@CLmoss wrote:

... Can you NOT bend sheet metal in Fusion?

Bending a flat is (almost) always the incorrect technique in any MCAD software that has sheet metal tools.

You should be able to model anything (finished form) with standard tools that can be modeled with sheet metal tools.

The sheet metal tools are simply optimized to follow standard rules like uniform thickness, cylindrical or conical bends...

The customer pays for the finished form, so you should be modeling in finished form.

The fabricator should have the knowledge and experience of creating part from the finished form dimensions.

Now if you are making in-house or working very closely with the fabricator - you could (if Fusion had the tool) supply a Flat Pattern.

But each material and process tooling has specific parameters that influence how you create the Flat Pattern.

When you bend material - the material compresses on the inside bend radius and stretches on the outside bend. The "neutral plane" (no bending or stretching) is generally not smack in the middle of the thickness.

The fabricator uses a "k-factor" or bend table or formula (see your Machinery's Handbook) to determine the correct flat pattern dimensions to end up with the correct finished form dimensions (the product that the customer pays for).

So model away keeping uniform thickness and cut out of paper your idea to make sure unfolding will not result in interference. Attach your *.f3d file here for someone with Autodesk Inventor (full set of sheet metal tools) to check.

Re: Sheet metal bending radius rules.

CLmoss — Sat, 04 Mar 2017 13:27:42 GMT

Very Interesting Post.

Can you show me an example of what you are saying? I mean, a video or how this is done like you say? An enclosure that will be made with sheet metal, that in CAD has been designed in finished form with standard tools. One that includes/shows overlaps and flaps or lips that are required for sheet metal strength and for attaching bottom and top plates?

See examples attached.

Re: Sheet metal bending radius rules.

TheCADWhisperer — Sat, 04 Mar 2017 14:54:04 GMT

How much modeling experience do you have?

Can you make an attempt yourself and attach the result here?

Re: Sheet metal bending radius rules.

CLmoss — Sat, 04 Mar 2017 15:14:09 GMT

Well, I am an old fashion guy. This is my first CAD effort. To create the prototype I just used, I think I said this above, measuring instruments, power saws and a drill press. I created a working model using these. Now it is time to use Fusion 360 to formalize all the elements into one set of drawings. I am a programmer and electronic designer. So I know about software. I am not a mechanical engineer. I do know what I want as I have already made a hard model. If you cannot bend aluminum in Fusion 360, then, where do you go?

My question is to anyone who sees things in Fusion they way you do, that can demonstrate it with a link to some video somewhere. I really don't want to try to reinvent the wheel here by successive attempts at an approach that I have just heard about and not sure even works. That would not work. I appreciate your input and want to believe it. I just don't understand clearly how this would work in Fusion 360. If you cannot bend aluminum in Fusion 360, then, where do you go from that point? I think you are stuck. There must be some support videos or instructions with drawings out there that demonstrate doing what you said.

Again, reference my photo links above.

Re: Sheet metal bending radius rules.

TheCADWhisperer — Sat, 04 Mar 2017 16:56:08 GMT

@CLmoss wrote:

... If you ~~cannot bend aluminum~~ in Fusion 360, then, where do you go?

If you ~~cannot bend aluminum~~ in Fusion 360, then, where do you go from that point? I think you are stuck. ....

Again, reference my photo links above.

Very simple.

You model in the finished form - just like in your photos.

Even if you could Bend, (or Fold) that is (usually) not the correct technique to model a sheet metal part in an MCAD software.

Have you gone through the Help>Tutorials?

Can you create a fully dimensioned sketch and an extruded box?

Nearly all of my models take 2 or 3 attempts at minimum.

I use what I learn from each successive attempt to hone in on my design intent.

Re: Sheet metal bending radius rules.

TheCADWhisperer — Sat, 04 Mar 2017 19:33:25 GMT

Can you sketch a rectangle with flanges at top and attach it here?

Re: Sheet metal bending radius rules.

CLmoss — Sat, 04 Mar 2017 20:23:26 GMT

I think this is the wrong way to go. This was the way to go when I created the front panel. However, this is the long way around the barn for an actual cage. With all the fancy constructions that are shown in the promotional materials, and in fact in the splash screen, it seems like there should be more flexibility to create here. Even if I made a flat cover for your box outline, considering the 1/16" material that I am working with, it would be impossible to join as there are no facing surfaces. Would I need to simply make flat pieces that float in space near each other?

Maybe we are overlooking something.

Is there a way to weld straight edges together, for example? I can see making an outline of, say, a cardboard box with no flaps using a cube then a -extrusion, but then when it comes to the flaps that seal the cardboard box, you are stuck. I am starting to see what everyone here is complaining about. There should be a way to make two objects stick together if you can't bend objects. Like the outline of the shell of the simple box and it's flaps. What? do I have to use screws for everything? Even that would not work with sheet metal because you need two facing surfaces.

It is weird. As I type here, to the the left of my dialog box, I see a breaker box with all kinds of bent sheet metal.

What is the purpose of Fusion 360? I mean, Autodesk already has Autocad. Why did they start this program up?

Re: Sheet metal bending radius rules.

CLmoss — Sat, 04 Mar 2017 21:01:12 GMT

Maybe I could make a box. Then do a -extrusion that comes within 1/16" of the top and bottom. Then another -extrusion that takes out everything but the lips on the top and bottom. Then a -extrusion that takes out all of the back but for the back lips. That might work.

This reminds me of the early dbase programs where you have to make a everything out of like 5 commands.

Re: Sheet metal bending radius rules.

CLmoss — Sat, 04 Mar 2017 21:04:19 GMT

Then cut out thin corner slots on the lips to allow for bending.

Re: Sheet metal bending radius rules.

TheCADWhisperer — Sat, 04 Mar 2017 21:40:55 GMT

@CLmoss wrote:

I think this is the wrong way to go. .....

Good luck with your efforts!

Re: Sheet metal bending radius rules.

CLmoss — Sat, 04 Mar 2017 21:50:26 GMT

Yes. Not just me. This thread is likely being read by thousands of users in the same situation. Good luck to all of us.

Re: Sheet metal bending radius rules.

TheCADWhisperer — Sat, 04 Mar 2017 22:42:47 GMT

@CLmoss wrote:

...What is the purpose of Fusion 360? I mean, Autodesk already has Autocad.

@CLmoss

Oh man, that is a blast from the past. I remember starting out on AutoCAD 30 yrs ago.

In this century, I use modern MCAD tools.

Re: Sheet metal bending radius rules.

CLmoss — Sat, 04 Mar 2017 22:59:43 GMT

Right...

So, what about my question. I know people using AutoCad to create enclosures just like I attached in my previous posts. Is it the ability to do the CAM part? I looked up MCAD and could not find what that means exactly. At least enough to differentiate it from what AutoCad does. I mean, you posted graphics of, what I am assuming are your past projects, and they show bent sheet metal. Those must be from your Autocad days, correct?

I tried to learn AutoCad when it was in DOS just enough to lay traces on PCBs. The learning curve was not worth the time. I am starting to get Fusion in a very limited way of course. At least I can find the bathroom.

Re: Sheet metal bending radius rules.

TheCADWhisperer — Sat, 04 Mar 2017 23:19:30 GMT

@CLmoss wrote:

... I looked up MCAD and could not find what that means exactly. ...

.....I tried to learn AutoCad when it was in DOS just enough to lay traces on PCBs. .....

MCAD = Mechanical - Computer Aided Design (as perhaps contrasted to Architectural or Civil or ...).

Another trip down memory lane.

Back in the last century I used to teach laying out PCB traces, photo screening and etching.

This was a controller interface to Parallel Port (remember those) and programmed with QBASIC.

Back then we were making the transition from through-hole to surface mount components.

Re: Sheet metal bending radius rules.

TrippyLighting — Sat, 04 Mar 2017 23:36:12 GMT

What a blast from the past!
I did the keystone project work for my engineering degree 30 years ago in AutoCAD including the PCB design. Hatching a cross section in AutoCAD on DOS was hit or miss. Ethced and hand populated the PCB's more or less on the Kitchen table . Before that it was rub-on symbols and traces.

I feel ill hanging out over a beer reminiscing these times 😉

Re: Sheet metal bending radius rules.

CLmoss — Sun, 05 Mar 2017 00:10:36 GMT

Right. Well, I used rubylith on 20x drawings to make ceramic hybrids from 1978 to 1989 when I went back to school for a degree in Businesss. I had parts on the space shuttle as well as many other places. I was published by IEEE. Now I am trying to make enclosures with Fusion 360. So once more, why did Autodesk create Fusion and not just continue with plug-ins for Autocad?