Sheet metal development

[eski1]

Hello
Is there a sheet metal development tool for working out the flat sheet size for autocad
I currently use Autocad 2002LT
Cheers
Chris

 

[berkshire]

try,

http://www.litio3d.com.ar/

This is a German program that unfolds sheetmetal parts in AutoCAD.
B.E.

 

[eski1]

Cant get that to work on my copy of 2002Lt
Could it be that lt dosen't let you do it

regards henry

 

[diamondjim]

It does not list 2002LT as an
option or any LT version.

 

[berkshire]

eski1
It may be that Auto CAD 2002LT does not have 3D capability.
Here is what Litio will work with:The program runs within AutoCAD (AutoCAD R2000 or later: 2005, 2004, 2002, 2000). It has the same hardware requirements as to run AutoCAD (if you can run AutoCAD successfully, you can run the program). If you cannot generate a solid I cannot see this progam working for you.
B.E.

 

[xgrigorix]

Berkshire,

AutoCAD LT does not have any 3d capabilities. It is really just an electronic drafting board.

When I've have to figure out flat pattern on LT (a thankless task to say the least), I have drawn my part in its folded form, and then worked backwards from that. Keep in mind that the centerline of the thickness of the sheet will not yield you your blank size. Material is compressed to the inside of the bend & expanded on the outside. Typically the neutral plane that will give you you flat pattern size is 44% of the thickness (from the inside). It get more complicated when you have bends going in different directions. In this case some fudging must take place.

Also keep in mind what your radii will be. For a simple bend on a brake, for simplicities sake I will use the material thickness for the inside radius.

I conclusion, LT is not the tool you want for developing sheet metal flat patterns (at least on a regular basis). Just laying out the reality of the situation.

 

[berkshire]

xgrigorix (Specifier/Regul)
Then for what eski1 was looking for the Litio3d will not work. You are correct in your statement that the centerline will not give you the correct stretchout.
An empirical formula that I use, that gives fairly accurate results is " (.0078*t)+ (r*.01743)*A where t is the thickness R is the inside bend radius and A is the angle of bend. This formula will work for aluminium and soft steels. If the material is harder then the neutral line will move.At which point you will have to calculate the k factor for the metal concerned.
B.E.

 

[xgrigorix]

Your method is certainly a wee bit more sophisticated than mine, berkshire.

It is interesting to know this information, but none the less, it is not something that I would want to be figuring out like that on a regular basis. There are more powerful software packages out there.

Have fun with this, eski1. Perhaps its time to upgrade.

 

[IFRs]

berkshire - what units are you working with?
thickness = inches?
radius = inches?
angle = degrees?

 

[berkshire]

Yes,
You can subsitute MM for inches in this formula but you have to stick with degrees since The number .01743 is pi for one degree.
B.E.

 

[smcadman]

How complicated are your parts? Are we talking pans and some not-so-complicated parts or are we talking about square-to-rounds, transitions, elbows for ductworks?

If your parts aren't complex, then Bendworks is a program that I have recommended for several years now. You can use imperial or metric units, enter your own k-factor or use some predefined k-factors for air-bending, aluminum, stainless steel, etc.

One of the best things about this program is that you can reverse-engineer the k-factor for your tooling by shearing a part, measuring it, and then taking the measurements after braking it.

It is completely free and found at

http://www.massey.ac.nz/~odiegel/bendworks/

Correct me if I'm wrong, but I have heard that Solidworks doesn't cost too much more than full-blown AutoCAD (not ACAD LT). SW has a powerful sheet metal package built in, and stepping up to SW may be cheaper than rebuilding your parts.

Flores

 

[berkshire]

smcadman
I did not want to mention brand X in this forum but since you have, I must admit that this is the cad system I have switched to. It takes all of the "fun" out of sheet metal patterns. It just does them.
B.E.

 

[thalon]

I have a small program that will create flat pattern layouts (dxf) for all sots of sheet metal trransitions. It fits on a single floppy disk.
It's many years old (10-15) but work well. If you want more info please let me know.