Detailing up a Sheet Metal Drawing 1

[AeroNucDef]

Hi all,

I've been told by my manager that I will be doing some sheet metal design work in a couple of weeks, I think it's something like transition cones, and a few boxes. I'm OK at creating the parts but I have no idea how to detail up a sheet metal drawing.

I know that SW's automatically puts in the bend orientation on a flatten sheet drawing, but how would I include all the bend radi, bend allowance, and so on.

Could someone please upload a pdf or jpeg of a fully detailed sheet metal drawing so that I could do a little learnin' please.

Thanks all.

 

[newma]

Check the attached PDF file.

mzn

 

[PatCouture]

I think the best resource for the right answers would be the place where the bending will be done. If it's done by a subcontractor I'm pretty sure he will be able to tell you exactly what information is required on the drawings.

Patrick

 

[AeroNucDef]

Newma, Thanks for the drawing. I noticed that it's just detailed up as a regular part, which is good news. I always thought that I would have to flatten the part, then detail it.
Many thanks

Hi Patrick, Thanks for the info. I'm going to ask the company that does the work for their bend tables.

 

[Updraft]

iwonafish,

If you are buying a complete part from a vendor then you really should not need to supply a flat pattern. Technically you do not care how they arrive at the finished part so long as they meet your specifications. However, there are many sheet metal shops that are using SWX or other 3D products so having your finished part in a suitable solid format is typically a huge benefit. It saves them the time and trouble of recreating the part from your drawing.

You definitely should confer with your vendor and find out what you can do (drawing and solid file of the finished part at least) to make it easy for them to be successful for you. That is mutually beneficial.

- - -Updraft

 

[Updraft]

I meant to add that if the vendor is using 3D software they can take the solid of your finished part and flatten it with their own bend data.

- - -Updraft

 

[fcsuper]

I'm not sure your exact situation, but the drawing should represent your final product. It may not be valuable to you or your vendor for you to create flat patterns. Flat patterns, bend radii, k factors, etc can be shop specific and even machine specific. Design and draw your sheet metal in the final state. If you vendor wants your files to create their own flat pattern, then that will be better than you trying to create one for them.

Matt Lorono, CSWP
Lorono's SolidWorks Resources & SolidWorks Legion
Follow me on Twitter

 

[ctopher]

I'm not sure how to "detail up" a drawing.


Chris
SolidWorks 10 SP4.0
ctopher's home
SolidWorks Legion

 

[DiegoLGraves]

fish, it's helpful to the sheet metal shop to dimension with your design in mind. Use the dimensions to indicate the fit required - inside dimensions where required, outside dimensions where required, feature to feature, or feature to edge/surface. Ordinate dimensions often don't show your intentions. Gtol helps if applied correctly. Please tolerance accordingly. Block tolerances suitable for machining are often not economical for sheet metal.

A flat view is helpful for estimating cost and tooling. You can mark your flat layout reference only. On a complicated sheet metal part - multiple bends with limited gaging edges, a note stating optional construction methods may be acceptable will sometimes gain you a less expensive part.

One final note, the sheet metal shop will want to customize the flat blank to work with their tooling. For edge flanges use the flange position inside or outside, not the bend outside. It makes it simpler for them to make changes without reworking the model too much.

regards, Diego

 

[AeroNucDef]

Updraft,
Thanks for the reply. I asked the company who's going to manufacturer the part from my drawings for their bend tables and so on.

fcsuper,
Thanks for the advice. I'm starting to realize that doing a sheet metal drawing is the pretty much the same as any other part drawing.

Hi ctopher,
What I mean by "detail up" is putting the dimensions, notes, and so on on the drawing.

Hi Diego,
Thank for the advice, that's very helpful.
Should I include geometrical tolerancing on the drawing? Or is that going over the top. Because a lot of the drawings that I do do not require this.

 

[StrykerTECH]

Before sending it to the subcontractor making the part. Always verify that it does flatten, and is constructed in a manner that takes the bend radi and thickness out of the the tolerance equation. I.E. always bend inside, and thickness inside.
That way the manufacturer can change bend radi and k-factor and not change any of the critical to function dimensions on your overall formed part.

StrykerTECH Engineering Staff
Milwaukee, WI

http://www.stryker-tech.com/

 

[DiegoLGraves]

fish, the short answer to "Should I include geometrical tolerancing on the drawing?" is no. Unless, 1. you are trained to apply tolerance correctly, and 2. the overall project fit is controlled by Gtol.

Your mileage may vary. I love our customer who intelligently applies Gtol because it gives us freedom to make the part to fit. I also love our customer who intelligently applies linear tolerance because their manufacturing engineering review allows for normal variation.

If you make the outside dimension of the inside part the same as the inside dimension of the outside part, did you allow for variation? Can you use a slot in place of a hole? If you haven't been in a sheet metal fabrication shop, take the time to visit your vendor or your own shop, and see the equipment, processes and talk to some fabricators.

Regards, Diego

 

[fcsuper]

I think Diego's point about item 1 is that if you know GD&T, you wouldn't asked if it should be used. However, I would generally recommend to use GD&T (but learn it before you try to).

Matt Lorono, CSWP
Lorono's SolidWorks Resources & SolidWorks Legion
Follow me on Twitter

 

[DiegoLGraves]

Matt, thanks, you are correct.

 

[GRF]

Going back a few steps to the including flat view: We used to supply a flattened view on the print with the max length and width called out and bends lines showing all the intended bends (no dimenions on the bend line locations) on the print to give the supplier something to look at to come up with a quick idea on the amount of material they would need for the part and the bending for quoting purposes. We also would always supply a solid model of the part as well. For prototypes we usually only would supply the solid file.