When using the miter flange command in SolidWorks you have the option of setting a ‘Gap Distance’ as seen in this picture:
The gap distance was set as .069296 and the resulting ‘corner gap’ is .049. If you are wishing to add spotweld tab flanges that would fold inside of these existing flanges you need to have a ‘corner gap’ of slightly more than the material thickness. In this example I’m using 18ga which is why I went with the .049 corner gap. The mitered flange command does not give you the option of entering the ‘corner gap’ it only gives you the option of entering a Gap distance. How do you determine the Gap distance required to give you a desired corner gap?
The formula is:
where .049 is the desired corner gap.
The keystrokes on a TI 89 calculator is as follows: (replace .049 with the corner gap you desire)
KEY STROKES DISPLAY
2nd
√ √(
( √(( * - on a TI 86 press ‘(‘ twice
.049 √((.049
^ √((.049^
2 √((.049^2
) √((.049^2)
X √((.049^2)X
2 √((.049^2)X2
) √((.049^2)X2)
ENTER .069296…
With this useful piece of information I can now finish the part as such:
This started out as an exercise for myself wanting to get this procedure down on paper so I don’t have to think about when I need to do it. But I guess someone else might get some use out of it. Now I just need to create a function on the TI-89 to do this with less keystrokes…
Good tip. To simplify the function, the gap distance = corner gap * √2
ReplyDeleteYou can also use 1.414 as an approximation of √2. That might save you a bit more keystrokes.
Duh! Don't I feel dummb! Thanks
ReplyDeleteHi Jeff,
ReplyDeleteThanks for the articles on sheet metal! They are very informative. I'm one of those engineers that wish to learn more about how to properly design in sheet metal. Do you have some suggestions for me?
Thanks and keep up the great work!
Gabi,
ReplyDeleteComing from the point of being a sheet metal designer as well as seeing a lot of sheet metal designs from our customers I think the most important thing is to design your model from the start as a sheet metal part. This puts the sheet metal feature at the top of the design tree. I know that there are some instances where it seems that you can't get "there" that way but with a bit of forethought you might be able to and the stability of your model will be greatly enhanced.
Catch a Wayne Tiffany or Gerald Davis presentation. Gerald writes a excellent column that appears in "the Fabricator" every month. Both of these guys really know their stuff.
I hope this helps,
Jeff
If you want to calculate the exact value... You might think of adding a Design Table to a Template for sheet metal. Put the calculation no "Sheet2" and reference it on sheet one in the correct cell for whatever dimension name you need to use it with...
ReplyDeleteOr add it to the template as an equation and name it...so you can use it each time...