SolidWorks Gauge Table Setup & K-Factor Reverse Calculation

In SolidWorks 2009 Gauge Tables were expanded to incorporate;

a list of your stocked materials by gauge,

a list of your radius bend tools, sized for each gauge,

and a table of your custom K-Factors for each gauge, tool and bend angles!

Wow! That sounds great! So, uh, now how do I use this? How do I get it set up for our shop? That’s what this document is all about! For SolidWorks to calculate the blank length from your folded part or vice-versa we need to provide a few parameters. In particular; material thickness, bend radius, bend angle, and K-Factor. K-Factor being the compensation for the stretching & compressing that happens in the bend region. The theory is that somewhere thru the thickness is a neutral point/sheet where the flat and folded lengths are the same. Where this is from the inside of the bend is the key for SolidWorks’ K-Factor.

First, it’s important to point out that SolidWorks ships with some default tables and it’s recommended that you copy one of these as a starting point for your data. This way the formatting is preserved for it to function properly and this aids in getting help from others should you need it. ;-)

From this default SolidWorks table we can see the following:    
  

Type:  Not sure where this shows up other than in this table. Process: Shows up in the Property Manger of the Sheet Metal Feature in the Sheet Metal Gauges Group Box, Under the Table Name. Bend Type: Shows up in the Property Manger of the Sheet Metal Feature in the Bend Allowance Group Box as bold text left of Gauge Table Values. Material: Doesn’t seem to show up anywhere other than in this table.

Gauge No.: This is free text corresponds to the pull down in the Property Manager under Sheet Metal Parameters. Thickness: Value is shown in the property manager and is applied to the part. Angle: This is a column of bend angles for use. This will be presented in a pull down in the bend property manager. Radius: There is a row of what will be in bend radii pull down. This is where you’d put the tool sizes you have on hand and don’t want to deviate from unless really necessary. In this default table we see bend radii tool sizes of 0.25, 0.50, & 0.75. Below each tool radius size we see the K-Factor values. The default table shown has the same values listed several times.

Note: Make sure your gauge sizes are listed in ascending order otherwise you may receive an error when using your table that says; “Bend table is invalid”. Ref. SolidWorks Knowledge Base Article: S-022611

So, where do I get the K-Factors for my table that matches my shop?

This takes a bit of experimentation if you don’t already have the numbers. You’ll want to take a sample, measure the overall length, thickness, your bend die radius, and then bend it. Then measure the overall lengths and plug the values into the attached spreadsheet. This spreadsheet will help you reverse calculate the K-Factor for your Gauge Table.

 

Note: There two tables, one for 90 Degree bends and on for bends less than 90 degrees.

 

Note:Gauge tables are “copied” into your part file when first selected for use with the part, not referenced. This copy goes with the part should you send it to someone. I have not found a way to view or extract the table “after” it’s copied into the part. A painful side effect of the table being copied rather than referenced is if/when you choose to update the table in some way. In order to test it out or see the effect in a part, the table needs to be “re-copied” into the part. If the name of your table changed, that’s pretty obvious, but if you just overwrote the table you might think the part will “just update”, nope! You will need to edit the Sheet-Metal feature and either uncheck Use gauge table or chose a different one and pick ok. Then repeat and this time set it to Use the gauge table you just updated. This is why I created the spreadsheet to reverse calculate the K-Factors, to minimize the trial and error and reloading of the Gauge Table for test & verification purposes. 

How can I test my Gauge Table after I get those numbers in it?

I’ve attached two sample models where you can load in your Gauge Table and test it out. What’s handy about these parts is that they have many dimensions and equations in them so you can test and compare to make sure you’re getting out what you put into your Gauge Table.

 

Note: You’ll want to make sure to do a forced rebuild (Ctrl-Q) after changing anything (Gauge, Bend Angle, etc.) to update the equations.

 

Steps:

1. Open Part File for Angle Type.


2. Right Click on Sheet-Metal1, Edit Feature.


3. Browse for your Gauge Table,


4. Select Gauge & Bend Radius of choice.


5. Pick the Green Check.


6. Right Click on Sketched Bend1, Edit Feature.


7. Select Bend Angle of choice from pull down.


8. Select Bend Radius of choice from pull down.


9. Pick the Green Check.


10. Press Ctrl-Q to force rebuild.


11. Expand the Equations Folder.


12. Review Equation Values

Repeat as desired. 

Files:

K-Factor-90DegreeBends.sldprt-For testing parts with 90 degree bends. Download K-Factor-90DegreeBends

K-Factor-LessThan90DegreeBends.sldprt -For testing parts with angles less than 90 degree bends. Download K-Factor-LessThan90DegreeBends

Reverse-K-Factor-Calculations.xlsx -Spreadsheet to reverse calculate K-Factors from fabricated and measured samples. Download Reverse-K-Factor-Calculations

TESTING-K-Factor-In-Steel-90Bends.xls -Example Gauge Table I copied into the K-Factor-90DegreeBends.sldprt Download TESTING-K-Factor-In-Steel-90Bends

TESTING-K-Factor-In-Steel-LessThan90Bends.xls -Example Gauge Table I copied into the K-Factor-LessThan90DegreeBends.sldprt Download TESTING-K-Factor-In-Steel-LessThan90Bends