Sheet Metal lofts/shapes

[boylini]

Hi,

I am making a hopper to dispense sand, but I can't figure out the process to make the shape I want. I thought it would be easy! This is pretty much the first sheet metal part I've tried to make apart from easy tutorial things. I'm OK at normal parts.

I've mocked up the rough shape I want from a normal extruded part (attached). I've also attached the start of a folded version. I've had lots of attempts and none of them have really got anywhere.

How can I make this??

Thanks.

[IgorMir]

Could you send a screen shot of the item you are trying to model? I am with IV 2010 still.

Thanks,

Igor.

[JDMather]

This might give you some ideas.

Find the red End of Folded marker in the browser.

Drag the red EOF down step-by-step to see how I created the features.

I added two Corner Seams at the end to tighten up one of the corners. 

If you want to do this - experiment with the settings to see the possible results.

[JDMather]

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@IgorMir wrote:

Could you send a screen shot of the item you are trying to model? I am with IV 2010 still.

Thanks,

Igor.

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[JDMather]

I just realized that I missed one bend (actually Inventor did) - but you should be able to figure it out.

Since Inventor didn't auto-bend I would probably make the face with a gap where the bend should be and then add a Bend feature.

Oops, the fix is easier than I thought.  Examine the sketch for that face and you will see that I projected the wrong edge for the face (see the upper horizontal line).  I projected the inside edge rather than the outside edge.

[IgorMir]

Thanks Jeffrey,

Is that picture taken from your file or the OP one? Form that picture I can't really see how that hopper can be unfolded. I will give it some more thoughts...

Regards,

Igor.

[boylini]

Hey thanks a lot for your help guys, sorry I forgot to change the filetype Igor.

Your hopper looks really good JD. I don't totally understand how you made it yet but I'll study it carefully and figure it out.

Regarding the bend that didn't bend- I have adjusted that top horizontal line on Sketch 12, and it does seem to have bent it properly now. 

You also used 0.5mm thickness, which makes the edges join pretty nicely together. If I change this to 2mm though, then the edges move quite far apart. I put corner seams in the other corners to close them up, but then I get a warning-

If I Accept then it does it anyway but does this mean it cannot be physically made?

If I don't close the seams then the edge gap is possibly too wide to weld up:

Do you have any ideas?

[rdyson]

See attached, I edited the "long" corner seam per this:

And changed the "short" corner seams to arc weld.

That seems to have cleaned up the flat pattern but you might still want to do some edits on it to simplify these cuts:

[IgorMir]

Here is a model done in a Sheet Metal module. Flat Pattern is error free.

Regards,

Igor.

[Anonymous]

Sorry for hijacking onto this thread here, but I have opened the files you have provided to boylini, and have some questions,

Does one typically cut and bend a hopper such as this on one piece? I am just looking at the bend order annotation in the flat pattern view and it doesnt make sense to me (I am not implying that it is wrong)

I am curious as to how one would make this is a typical fab shop? I would split this into 5 sections??  Cut at bends 5, 3, 13 and 7. Am I making too much work for our welders?

Thanks!

[JDMather]

I don't think anyone here got that far yet (determining how many sheets of metal, or what order to make actual bends).
I think we were just trying show some examples of how to get the faces..

[Anonymous]

But how would one (using Inventor) and the part you attached above, come up with a set of fabrication prints? I understand the limitations are on what the brake operator can do, but is it impossible to build that hopper in one piece on brake press?

I started a thread here with something that was similar to this hopper but I decided to go with a skeletal type model because I needed the parts to be separate in order to get a proper flat layout for our burn table.

[rdyson]

This is what I was refering to needing cleanup. Probably okay for a laser cutter but could potentially drive a punch press crazy:

[JDMather]

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@Anonymous wrote:

 I would split this into 5 sections?? 

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I view my initial attempts at simply gaining an understanding of the geometry.
If splitting up into sections for fabrication purposes - it looks to me like at the most 4 sections (remove the Rip down the front).

[Anonymous]

Yes that is right, I forgot that you made that rip to allow for a flat to be created.

And would you use derive to extract your 4 separate parts?? This is where I get lost and unsure of how to proceed. I know how to make a final product, (but not manufacturerable) so I typically create all my parts individually and place them into an assembly and check for fit. If i need adjustments, then I adjust the part. This method is much more work.

[JDMather]

If ended up ripping into more than two parts I would go back to Standard Part modeling environment (since Inventor doesn't support mutli-body solids in Sheet Metal Environment) and push out the individual parts with Manage>Make Components (this is really a short cut to Derived Components).  But yes, I would model all in one file to establish fit/clearances rather than fool with assembly environment.

[Anonymous]

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@Anonymous wrote:

 go back to Standard Part modeling environment (since Inventor doesn't support mutli-body solids in Sheet Metal Environment) and push out the individual parts with Manage>Make Components

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This is the step I was missing, I am getting the idea now!

Thanks for the help JD

[boylini]

Hi Sean, thanks for your interest in my hopper!
I actually have no idea what the best way to physically make something like this is.

I totally agree that looking at the bend order diagram it looks pretty difficult, if not impossible to make on a brake press.

We use a pretty good sheet metal shop to make things like this for us, and in the past I have just drawn something like JD has here- a drawing of a finished part without paying complete attention to its manufacturability. I carefully dimension it and make it clear that they can use whatever method they think is best to make it.

In this case though I think I will offer them the folded metal part and ask them if it is any use, otherwise I will separate it into 4 sides and they can cut it out and weld it up.

And thanks again for everyone's help. Is there anything JD doesn't know? How long have you been doing this??

[JDMather]

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@boylini wrote:
I totally agree that looking at the bend order diagram it looks pretty difficult, if not impossible to make on a brake press.

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Right click to Reorder Bends.