Sheet metal bending radius rules.

[CLmoss]

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 

[CLmoss]

We had better stop this trip down memory lane before everyone thinks we are all 100 years old. 

[HughesTooling]

Here's a quick demo of what's coming if you want to wait around for a while. You can request access to the preview here.

Mark

[CLmoss]

NOW THAT IS WHAT I'M TALKING ABOUT!  WHEN? IS THERE A DATE?  

[HughesTooling]

Don't know when, if you read through the preview forum posts there might be something. This thread has some info on what's planned.

Mark

[CLmoss]

I saw that.  From your video it seems to be working fine. 

[CLmoss]

Are you evaluating the Beta version yet?

[CLmoss]

In line with what TheCATWhisperer said here was reflected in an email from a sheet metal forming shop this morning.  

He said  the following:

As for what we will need to make parts, we prefer the 3 view orthographic file, either .dxf or ‘dwg format. Don’t even bother with the unfolding, it’s never correct. Since Solidworks came out, what, some 20 years ago, I have seen exactly one correct unfold. Even if the bend deduction is done correctly the corner notching never is.

Looking forward to seeing your work.

Life is like a spiral.  Up or down, it is always a learning curve. 

[mrm1018]

I would question your sheet metal forming shop then...

For my day job I use Solidworks, and have been for over 15 years...  In that time I've probably designed over 500 sheet metal parts, always using the flat patterns generated by Solidworks to either laser cut or CNC turret punch the flat sheet.  The flats were then either bent on a break press or panel bender, and I cannot remember a time where the flat was calculated so poorly by Solidworks that I couldn't get my part and it's flanges to be correct to plus/minus 0.030"....many times much better.

...but sure, if your K-factor is set ridiculously far off from reality, you betcha, your flats will absolutely be wrong.

[CLmoss]

Well, see.  There is another valuable opinion.  

Folks, this is called WISDOM.  Don't forget it.  

Wisdom is the result of life experience.  

Thank you for your input. 

JM

[CLmoss]

Just like the sheet metal house owner above.   

The Wisdom of life experience. 

So, where is the discrepancy?

Both True Life experiences.  

As a programmer I must recognize that all inputs are valuable.

As a programmer I must recognize that all inputs might, in fact, be true.

Therefore, I would look at details such as variable settings, like suggested or the fact that the systems might not be compatible. Maybe there are problems with drivers or the software that uses the drivers. We cannot assume that just because we make a statement in flat metal software such as Solidworks, that true communication has taken place.  Anyone here ever heard of Positive Listening? This is done in software too.  You can make all the statements you want, but if the listener is listening in another language, although close to what you are using, it might not be received correctly or to the tolerance that you need.  Has anyone here in the USA visited places like Scotland and heard the countryside accents there?  I did with my band.  There were times that I could not make anything out of what was being said to me.  I could hear what sounded like English sounds, but there was no pattern recognition in my head that would produce words to me.  I listened over and over without getting what the person was saying.  Then to top it off, they said they liked my accent.  That it sounded "Rock & Roll".  (My what? I am from SF.  I have no accent... or do I.  Like currency exchange rates, it is all relative).  Something like this could be happening between the Solidworks and the sheet metal house software installations.  

My thoughts here.... also Wisdom. 

JM

[TheCADWhisperer]

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@CLmoss wrote:

I must recognize that all inputs might, in fact, be true.

.... Maybe there are problems with drivers  

---

You hit the nail on the head, almost.

The problem is with the driver (operator, the "software" sitting in chair typing at the keyboard to interface with the computer), not the computer software.

Anyone who knows what they are doing can create a proper Flat Pattern from SolidWorks sheet metal, but first is an understanding that this requires communication with the shop floor and an understanding of k-factors, bend allowances, bend deduction formulas (be honest, did you pull out your Machinery's Handbook and take a look).

I tried to walk you through a solution to your problem (in current release of Fusion) step-by-step, but you rejected my technique on the first step.

Good luck!

[mrm1018]

Whisperer is absolutely right...Solidworks or Fusion will not do the thinking for you.  It'll only automate the stuff you set up.  So yeah, if you don't understand how a break press works, or know why bend allowance is important...you'll probably get lots of bad flats.  Garbage in - garbage out as they say.

...but without a doubt, setup correctly CAD software capable of generating flat patterns do an amazingly good job.

-Mike

[CLmoss]

Cat Whisperer,

you should not hang onto things so much.  Gosh, as a performer if I hung onto every "slight" rejection I ever heard over the last 40 years I would be dead by now.  This is a learning environment.  I am learning from everyone, including the one man shop owner with an ME who has been in business for 30 years now, here in the Silicon Valley and others.  I think he knows a thing or two.  Just like the people here. Within minutes, I responded to your email with a method to use negative extrusions that I thought might work and pretty much followed your approach.  No, I did not "pull out a Machinery's Handbook and take a look". I don't have one and have no intention of getting one.  I just emailed a couple of shops and asked them.  They are the ones working the metal. They work with this all the time.  I am an Electronics Designer Published by IEEE with a BS In Business not an ME.  I have a need for a custom rack mount enclosure.  I have tons of of reference material on Electronic Engineering, Business and programming.  I did exactly what you now recommend.  I communicated with the shop floor which is in somewhere other city than here.  

Learning is not a smooth process.  It includes testing of ideas.  That has been around since Socrates... or So-Cates as they said in the movie Bill & Ted's Excellent Adventure.  I still wonder if there are not tricks that allow the joining of two parts without needing to use the negative extrusions out of a block of metal.  There are a lot of people here who might have figured out a workaround of some kind or another.  To have a bunch of unconnected sheets of metal floating in space, looking like a box, like you suggested, just cannot be all that we are left with. 

So I will charge on in my learning of this process.  

Thanks for your reply to my post and thank you for your best wishes. 

JM

[TheCADWhisperer]

---

@CLmoss wrote:

... To have a bunch of unconnected sheets of metal floating in space, looking like a box, like you suggested, ... 

---

Huh?

[CLmoss]

Yeah, you asked "Can you sketch a rectangle with flanges at top and attach it here?".  Flanges?  You cannot bend metal here.  Flanges would need to be on the same plane as the sheet of metal.  That was when I posted my approach of hollowing out a box, but leaving the the flanges using negative extrusions.  If you cannot bend metal, then you just have negative extrusions to work with. Go back and read the thread.  

[TheCADWhisperer]

I guess I was thinking 3 steps down the road.

Let's back up and start with Step #1.

Sketch a Rectangle and then attach your *.f3d file here.

[CLmoss]

Do you want a 2D or 3D?  Here is a Sketch 2D.

[CLmoss]

Did you see in this thread where you said the following?

---------------

CAT Whisperer

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.

---------------

That was when I said:

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.

---------------

Your comment seemed to go along with the sheet metal shop owner here who said the following.

As for what we will need to make parts, we prefer the 3 view orthographic file, either .dxf or ‘dwg format. Don’t even bother with the unfolding, it’s never correct. Since Solidworks came out, what, some 20 years ago, I have seen exactly one correct unfold. Even if the bend deduction is done correctly the corner notching never is.

---------------

I am swimming through dark and cloudy waters here.  

I am NOT the expert here.  

[TheCADWhisperer]

---

@CLmoss wrote:

Do you want a 2D or 3D?  Here is a Sketch 2D.

---

I will try to use very precise language here on out.

A rectangle is a planar 2D object, not 3D.

In the file that you attached there are two sketches with a rectangle in each.  I would delete the undimensioned sketch.

Your design will have an overall Width (distance from left to right), Depth (distance from front to back), and Height (distance from bottom to top).

>As for what we will need to make parts, we prefer the 3 view

Your rectangle should have two of these 3 dimensions - Width, Depth, Height.

From your file you have Depth as 4" (I was expecting greater distance) and Height as 2".

Are these the correct dimensions for your Depth and Height?

[CLmoss]

I disagree.  In my drawing there is one sketch with a single rectangle. See Attached. 

However, the dims are 2" x 4".  It has a Y of 2" and a X of 4".  

I am not sure what you were expecting, but for a demonstration I thought this would be fine.  I could change if you like.  Just tell me what dims you would like to see.  I looked at your first post on drawing this and it was for 5.23" x 19".  That would be the size of the front panel.  However, what I am working with now is the cage behind the front panel.  That is where the bends are needed.  The front panel is completed already.   I am not sure where we are going.  A list of steps might help me.  I think the cage dims are 4.75" x 17" x 17". I would need to double check them though as I have been focused on the front panel during this first period. 

JM