Inventor General Discussion

Inventor General Discussion

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*Tim W.
Message 1 of 15 (900 Views)

Dan Z. -> K-Factor & Bend Allowance spreadsheet

900 Views, 14 Replies
06-15-2004 12:40 PM
Dan Z., this is especially for YOU. However, it also applies to everyone using Sheet Metal in Inventor: I've created an excel spreadsheet to figure out K-factors and Bend Allowances. Right now it works with "Inches" as the unit of measure. I too have been upset with how complicated it is to modify K-Factors and Bend Tables. I don't use the same equation that Inventor uses, I use this one for Bend Allowance: Bend Allowance = [ ( Thickness x F-Factor ) + (Bend Radius x 1.57 ) ] x ( Bend Angle / 90° ) The F-Factor which is specific to steel, hard brass, copper, and aluminum is 0.64. Use an F-Factor of 0.55 for soft brass & soft copper OR 0.71 for bronze, hard copper, and spring steel. Then, I use this one to determine the K-Factor from the Bend Allowance: Bend Allowance = PI x ( Bend Angle / 180° ) x ( Bend Radius + ( K-Factor x Thickness ) ) Re-arranging it to solve for the K-Factor, the equation becomes: K-Factor = [ Bend Allowance / PI x (Bend Angle / 180°) - Bend Radius ] / Thickness There are some other things I threw in to the equations like unit "round-off", and something I call "small bend angle correction". There are also two Bend Tables included - one for the specified Thickness & Bend Radius only, the second includes editable Bend Radii and the specified Thickness. Both go from 0 to 180 degrees in 1 degree increments. These worksheets should be saved as txt files and imported into your current sheet metal style. BUT you've got the option to use just the K-Factor, OR just the Bend Table, Or both (by using different Sheet Metal Styles). Because I don't want anybody tampering with the equations, the worksheet is password protected. I've also hidden the equations for now. This is mainly because I've put a lot of work into it, and I don't want someone suing me if they change something to make it calculate incorrectly. However, I will send an "unprotected" version directly to YOU if you post an email address that I can send to. (feel free to encrypt the address to avoid spammers, but just make the encryption something I can decipher). ... I haven't re-written it to work with "mm" yet, because I don't use those units for sheet metal. However, I think it still works without too much hassle if you just ignore the units. For now, wherever it says "in" think "mm". Obviously, you'll have to use the Custom Thickness feature exclusively. In the case of exporting a bend table, be sure to switch the units in the resulting *.txt file BEFORE importing it into Inventor!! The next version may include a switch for "mm". Please post any questions / concerns / differing ideas to the NEWSGROUP only! Also, be sure to read the instructions tab to learn how to use it and see a list of my assumptions. Best wishes, Tim W.
*Larry Caldwell
Message 2 of 15 (900 Views)

Re: Dan Z. -> K-Factor & Bend Allowance spreadsheet

06-15-2004 01:21 PM in reply to: *Tim W.
Looks like a nice job Tim. ~Larry "Tim W." wrote in message news:40cf509f_2@newsprd01... > Dan Z., this is especially for YOU. However, it also applies to everyone > using Sheet Metal in Inventor: > > I've created an excel spreadsheet to figure out K-factors and Bend > Allowances. Right now it works with "Inches" as the unit of measure. > > I too have been upset with how complicated it is to modify K-Factors and > Bend Tables. I don't use the same equation that Inventor uses, I use this > one for Bend Allowance: > Bend Allowance = [ ( Thickness x F-Factor ) + (Bend Radius x 1.57 ) ] x ( > Bend Angle / 90° ) > The F-Factor which is specific to steel, hard brass, copper, and > aluminum is 0.64. > Use an F-Factor of 0.55 for soft brass & soft copper OR 0.71 for bronze, > hard copper, and spring steel. > > Then, I use this one to determine the K-Factor from the Bend Allowance: > Bend Allowance = PI x ( Bend Angle / 180° ) x ( Bend Radius + ( K-Factor x > Thickness ) ) > > Re-arranging it to solve for the K-Factor, the equation becomes: > K-Factor = [ Bend Allowance / PI x (Bend Angle / 180°) - Bend Radius ] / > Thickness > > There are some other things I threw in to the equations like unit > "round-off", and something I call "small bend angle correction". There are > also two Bend Tables included - one for the specified Thickness & Bend > Radius only, the second includes editable Bend Radii and the specified > Thickness. Both go from 0 to 180 degrees in 1 degree increments. These > worksheets should be saved as txt files and imported into your current sheet > metal style. BUT you've got the option to use just the K-Factor, OR just > the Bend Table, Or both (by using different Sheet Metal Styles). > > Because I don't want anybody tampering with the equations, the worksheet is > password protected. I've also hidden the equations for now. This is mainly > because I've put a lot of work into it, and I don't want someone suing me if > they change something to make it calculate incorrectly. > However, I will send an "unprotected" version directly to YOU if you post an > email address that I can send to. (feel free to encrypt the address to avoid > spammers, but just make the encryption something I can decipher). > ... > I haven't re-written it to work with "mm" yet, because I don't use those > units for sheet metal. However, I think it still works without too much > hassle if you just ignore the units. > For now, wherever it says "in" think "mm". Obviously, you'll have to use > the Custom Thickness feature exclusively. > In the case of exporting a bend table, be sure to switch the units in the > resulting *.txt file BEFORE importing it into Inventor!! > The next version may include a switch for "mm". > > Please post any questions / concerns / differing ideas to the NEWSGROUP > only! Also, be sure to read the instructions tab to learn how to use it and > see a list of my assumptions. > > Best wishes, Tim W. > > > > >
*Gary W. Lynn
Message 3 of 15 (900 Views)

Re: Dan Z. -> K-Factor & Bend Allowance spreadsheet

06-15-2004 01:43 PM in reply to: *Tim W.
Tim, We would sure like to have a copy (with formulas & unprotected). Our "sheet metal" tends to run more on the side of "plate", so we need to expand the table. This is the best example I've run across yet - much better than the stock sample. Thanks in advance, Gary W. Lynn glynn@westerntrailer.com "Tim W." wrote in message news:40cf509f_2@newsprd01... > Dan Z., this is especially for YOU. However, it also applies to everyone > using Sheet Metal in Inventor: > > I've created an excel spreadsheet to figure out K-factors and Bend > Allowances. Right now it works with "Inches" as the unit of measure. > > I too have been upset with how complicated it is to modify K-Factors and > Bend Tables. I don't use the same equation that Inventor uses, I use this > one for Bend Allowance: > Bend Allowance = [ ( Thickness x F-Factor ) + (Bend Radius x 1.57 ) ] x ( > Bend Angle / 90° ) > The F-Factor which is specific to steel, hard brass, copper, and > aluminum is 0.64. > Use an F-Factor of 0.55 for soft brass & soft copper OR 0.71 for bronze, > hard copper, and spring steel. > > Then, I use this one to determine the K-Factor from the Bend Allowance: > Bend Allowance = PI x ( Bend Angle / 180° ) x ( Bend Radius + ( K-Factor x > Thickness ) ) > > Re-arranging it to solve for the K-Factor, the equation becomes: > K-Factor = [ Bend Allowance / PI x (Bend Angle / 180°) - Bend Radius ] / > Thickness > > There are some other things I threw in to the equations like unit > "round-off", and something I call "small bend angle correction". There are > also two Bend Tables included - one for the specified Thickness & Bend > Radius only, the second includes editable Bend Radii and the specified > Thickness. Both go from 0 to 180 degrees in 1 degree increments. These > worksheets should be saved as txt files and imported into your current sheet > metal style. BUT you've got the option to use just the K-Factor, OR just > the Bend Table, Or both (by using different Sheet Metal Styles). > > Because I don't want anybody tampering with the equations, the worksheet is > password protected. I've also hidden the equations for now. This is mainly > because I've put a lot of work into it, and I don't want someone suing me if > they change something to make it calculate incorrectly. > However, I will send an "unprotected" version directly to YOU if you post an > email address that I can send to. (feel free to encrypt the address to avoid > spammers, but just make the encryption something I can decipher). > ... > I haven't re-written it to work with "mm" yet, because I don't use those > units for sheet metal. However, I think it still works without too much > hassle if you just ignore the units. > For now, wherever it says "in" think "mm". Obviously, you'll have to use > the Custom Thickness feature exclusively. > In the case of exporting a bend table, be sure to switch the units in the > resulting *.txt file BEFORE importing it into Inventor!! > The next version may include a switch for "mm". > > Please post any questions / concerns / differing ideas to the NEWSGROUP > only! Also, be sure to read the instructions tab to learn how to use it and > see a list of my assumptions. > > Best wishes, Tim W. > > > > >
*Stephen R
Message 4 of 15 (900 Views)

Re: Dan Z. -> K-Factor & Bend Allowance spreadsheet

06-15-2004 01:59 PM in reply to: *Tim W.
Hello Tim, If you could send an unprotected copy, I would appreciate it. Thanks, Stephen R. srottloff@ no spam etcusa.com "Tim W." wrote in message news:40cf509f_2@newsprd01... > Dan Z., this is especially for YOU. However, it also applies to everyone > using Sheet Metal in Inventor: > > I've created an excel spreadsheet to figure out K-factors and Bend > Allowances. Right now it works with "Inches" as the unit of measure. > > I too have been upset with how complicated it is to modify K-Factors and > Bend Tables. I don't use the same equation that Inventor uses, I use this > one for Bend Allowance: > Bend Allowance = [ ( Thickness x F-Factor ) + (Bend Radius x 1.57 ) ] x ( > Bend Angle / 90° ) > The F-Factor which is specific to steel, hard brass, copper, and > aluminum is 0.64. > Use an F-Factor of 0.55 for soft brass & soft copper OR 0.71 for bronze, > hard copper, and spring steel. > > Then, I use this one to determine the K-Factor from the Bend Allowance: > Bend Allowance = PI x ( Bend Angle / 180° ) x ( Bend Radius + ( K-Factor x > Thickness ) ) > > Re-arranging it to solve for the K-Factor, the equation becomes: > K-Factor = [ Bend Allowance / PI x (Bend Angle / 180°) - Bend Radius ] / > Thickness > > There are some other things I threw in to the equations like unit > "round-off", and something I call "small bend angle correction". There are > also two Bend Tables included - one for the specified Thickness & Bend > Radius only, the second includes editable Bend Radii and the specified > Thickness. Both go from 0 to 180 degrees in 1 degree increments. These > worksheets should be saved as txt files and imported into your current sheet > metal style. BUT you've got the option to use just the K-Factor, OR just > the Bend Table, Or both (by using different Sheet Metal Styles). > > Because I don't want anybody tampering with the equations, the worksheet is > password protected. I've also hidden the equations for now. This is mainly > because I've put a lot of work into it, and I don't want someone suing me if > they change something to make it calculate incorrectly. > However, I will send an "unprotected" version directly to YOU if you post an > email address that I can send to. (feel free to encrypt the address to avoid > spammers, but just make the encryption something I can decipher). > ... > I haven't re-written it to work with "mm" yet, because I don't use those > units for sheet metal. However, I think it still works without too much > hassle if you just ignore the units. > For now, wherever it says "in" think "mm". Obviously, you'll have to use > the Custom Thickness feature exclusively. > In the case of exporting a bend table, be sure to switch the units in the > resulting *.txt file BEFORE importing it into Inventor!! > The next version may include a switch for "mm". > > Please post any questions / concerns / differing ideas to the NEWSGROUP > only! Also, be sure to read the instructions tab to learn how to use it and > see a list of my assumptions. > > Best wishes, Tim W. > > > > >
Distinguished Contributor
dzender
Posts: 184
Registered: ‎05-24-2004
Message 5 of 15 (900 Views)

Re: Dan Z. -> K-Factor & Bend Allowance spreadsheet

06-16-2004 09:29 AM in reply to: *Tim W.
Tim,

Thanks a lot.

Your table looks alot different than inventors samples, which make me wonder even more what the heck inventor looks at when it is reading the table. Currently I use (Bend Allowance = PI x ( Bend Angle / 180° ) x ( Bend Radius + ( K-Factor x
Thickness ) ) ) for bend length using the K-factor values .5 and .3333 under certain conditions.

I will try this out and see how it works!
Distinguished Contributor
csmac2004
Posts: 390
Registered: ‎03-03-2004
Message 6 of 15 (900 Views)

Re: Dan Z. -> K-Factor & Bend Allowance spreadsheet

06-16-2004 10:45 AM in reply to: *Tim W.
I wouldn't mind having a copy, but I can't find where it is posted (the protected version). My email is scott@jireh-industries.com
Scott MacDonald
Inventor 2013 Product Design Suite
Vault Professional 2013
Windows7 x64
Autodesk Inventor Certified Professional
Distinguished Contributor
Michael Quinn
Posts: 117
Registered: ‎01-07-2004
Message 7 of 15 (900 Views)

Re: Dan Z. -> K-Factor & Bend Allowance spreadsheet

06-16-2004 11:07 AM in reply to: *Tim W.
Hi Tim
It sounds like we my be able to use this spread sheet. Could you post this for the group or if you are sending copies to others here is my email.
Thanks
Mike
mquinn@dewengineering.com
*Dan Z.
Message 8 of 15 (900 Views)

Re: Dan Z. -> K-Factor & Bend Allowance spreadsheet

06-16-2004 11:27 AM in reply to: *Tim W.
It is my first time using the news group envirenment so hopefully this post goes through. "Tim W." wrote in message news:40cf509f_2@newsprd01... > Dan Z., this is especially for YOU. However, it also applies to everyone > using Sheet Metal in Inventor: > > I've created an excel spreadsheet to figure out K-factors and Bend > Allowances. Right now it works with "Inches" as the unit of measure. > > I too have been upset with how complicated it is to modify K-Factors and > Bend Tables. I don't use the same equation that Inventor uses, I use this > one for Bend Allowance: > Bend Allowance = [ ( Thickness x F-Factor ) + (Bend Radius x 1.57 ) ] x ( > Bend Angle / 90° ) > The F-Factor which is specific to steel, hard brass, copper, and > aluminum is 0.64. > Use an F-Factor of 0.55 for soft brass & soft copper OR 0.71 for bronze, > hard copper, and spring steel. > > Then, I use this one to determine the K-Factor from the Bend Allowance: > Bend Allowance = PI x ( Bend Angle / 180° ) x ( Bend Radius + ( K-Factor x > Thickness ) ) > > Re-arranging it to solve for the K-Factor, the equation becomes: > K-Factor = [ Bend Allowance / PI x (Bend Angle / 180°) - Bend Radius ] / > Thickness > > There are some other things I threw in to the equations like unit > "round-off", and something I call "small bend angle correction". There are > also two Bend Tables included - one for the specified Thickness & Bend > Radius only, the second includes editable Bend Radii and the specified > Thickness. Both go from 0 to 180 degrees in 1 degree increments. These > worksheets should be saved as txt files and imported into your current sheet > metal style. BUT you've got the option to use just the K-Factor, OR just > the Bend Table, Or both (by using different Sheet Metal Styles). > > Because I don't want anybody tampering with the equations, the worksheet is > password protected. I've also hidden the equations for now. This is mainly > because I've put a lot of work into it, and I don't want someone suing me if > they change something to make it calculate incorrectly. > However, I will send an "unprotected" version directly to YOU if you post an > email address that I can send to. (feel free to encrypt the address to avoid > spammers, but just make the encryption something I can decipher). > ... > I haven't re-written it to work with "mm" yet, because I don't use those > units for sheet metal. However, I think it still works without too much > hassle if you just ignore the units. > For now, wherever it says "in" think "mm". Obviously, you'll have to use > the Custom Thickness feature exclusively. > In the case of exporting a bend table, be sure to switch the units in the > resulting *.txt file BEFORE importing it into Inventor!! > The next version may include a switch for "mm". > > Please post any questions / concerns / differing ideas to the NEWSGROUP > only! Also, be sure to read the instructions tab to learn how to use it and > see a list of my assumptions. > > Best wishes, Tim W. > > > > >
New Member
stuart_worc
Posts: 1
Registered: ‎10-05-2004
Message 9 of 15 (900 Views)

Re: Dan Z. -> K-Factor & Bend Allowance spreadsheet

10-05-2004 06:29 AM in reply to: *Tim W.
Any chance of a copy - We have all but given up trying to do it ourselves !

thanks

E-mail stuart.wilson@thorlux.co.uk
Active Contributor
Nicholas Webb
Posts: 28
Registered: ‎11-11-2004
Message 10 of 15 (900 Views)

Re: Dan Z. -> K-Factor & Bend Allowance spreadsheet

11-11-2004 03:46 AM in reply to: *Tim W.
Very impressed with your tables, have you done the mm version yet?

As a relative beginner, where do you put the table so that sheet metal style looks at it?

Cheers
Nick

Ps, can you send a table to edit?
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