It is a kfactor calculator developed by the new zealand company knac solutions. We also perform sheet metal bending with modern machines, that are supported by computer cnc steering. Select fixed face surface from where all bends will be defined step4. Sheet metal parts are some of the most important semifinished products. From there we can calculate the k factor and the bend deduction. Clinching process is used to join different material and sheet thickness parts. In sheet metal, the kfactor is the ratio of the neutral axis to the material thickness.
Sheet metal fabrication is the process of forming parts from a metal sheet by punching, cutting, stamping, and bending. This video shows the new format of k factor extracting from excel files in sheet metal. When metal is bent the top section is going to undergo compression and the bottom section will be stretched. Cutting of sheet metal is done on tested machines, where we can ensure quality cutting with appropriate tolerances. There are many other tools that can be used with this software. When you select kfactor as the bend allowance, you can specify a kfactor bend table. The sheet metal model built with the sheet metal addon rear. See more ideas about sheet metal, metal, metal bending. In reality, how a real metal part will stretch as it bends depends on a number of physical factors tooling, material homogeneity etc. How to create a custom solidworks sheet metal bend table. The sequencing of part setups, in the context of design verification or process planning activities for sheet metal bending operations, is a rather complex combinatorial problem.
Miter flange, loftedbend, corner controls, sheet metal gusset and rip are all very common tools that can make life easier for the designer. Unfold your sheet metal part and by adjusting the kfactor try to bring your bending line in a desirable distance. Similar to other metal forming processes, bending changes the shape of the work piece, while the volume of material will remain the. This causes alteration of the original form of the sheet as it passes through a pathway of series of rollers. Once the ba is determined solidworks can calculate the flattened length of the bend using the method below. When a piece of metal is being formed, the inner portion of the bend compresses while the outer portion expands see figure 1. Mathematically k factor is equal to position of neutral axis divided by sheet thickness. Sheet metal bending straining sheetmetal around a straight axis to take a permanent bend figure 20.
Methods for the sequencing of sheet metal bending operations. Sheet metal bend allowance calculations with solidworks. The kfactor depends on many factors including the material, the type of bending operation coining, bottoming, airbending, etc. It is a type of permanent sheet metal joining operation. Or y factor in the case of proe where y factor k factor 2. Many years of experience in sheet metal cutting proves that we provide quality service within the agreed time limits. A reader wrote me asking me about the kfactor and calculating bend allowances.
To be familiarized with different sheet metal joining operations and to make a. Shows up in the property manger of the sheet metal feature in the sheet metal gauges group box, under the table name. The bend allowancebend deduction of the sheet metal specified in kfactor by configuring and utilizing a sheet metal gauge table, we can speed up the process of selecting the correct wall thickness based on gauge value and selecting. It ultimately allows you to estimate the amount of stretch without knowing what type of material you are bending. Sheet metal bending bending of sheet metal is a common and vital process in manufacturing industry. V l2 rt bend allowances for cincinnati incorporated. Not sure where this shows up other than in this table. 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. A few among the most common applications of sheet metal parts are as automobile and aircraft panels, housings, cabinets. This allows me to take the measurement of the length of the bend. Solidworks sheet metal tools are relatively straight forward, but may not be clearly understood.
In practical terms, its just a generic bend allowance to use when you dont know the process or machine that is going to be used to bend the sheet. When working in solidworks to create sheet metal designs, we will often need to know three important values. In sheet metal design, the kfactor is used to calculate how much sheet metal one needs to leave for the bend in order to achieve particular final dimensions. Specify sheet metal parameters such thickness, internal bend radius and k factor. Sheet metal clinching joint creates a buttontype positive connection between two or three layers of sheet metal. Values for angles not defined within the table are calculated using a backup kfactor select bend table as the unfold method. One of the most important aspects of good sheet metal. Pdf the study of design constants in sheet metal forming. Figure 2 illustrates the sheet that is bent with the bend angle of 90 degrees. Then input the bend angle to get the arc length, bend allowance and bend deduction. Using the bend table unfolding method, sheet metal parts unfold using empirical values that are measured or derived and applied to specific bend angles within the table. Most sheet metal shops will produce their own bend tables by physically bending test pieces to specified angles and taking accurate.
Since the inside compression can not exceed the outside tension, the kfactor can never exceed. Registered users 82,370 forums 1 topics 45,379 replies 217 topic tags 4,399. The kfactor in sheet metal working is the ratio of the neutral axis to the material thickness. All sheet metal workers know the importance of an accurate kfactor or bend allowance when it comes to design. It involves joining sheet metal parts using cold forming operation. Weve even developed our own inhouse tools, spreadsheets, or other cheat sheets to get close enough because no one wants to do the math each time. The kfactor approximations given below are more likely to be accurate for air bending. Its the base value needed to calculate bend allowances and ultimately the bend deduction. Sheet metal bending is the plastic deformation of the work over an axis, creating a change in the parts geometry. In the flat patterned state i have the merge solids option selected off. After bending the sheet, insert the inner radius, and flanges a and b. The bend deduction is the amount the sheet metal will stretch when bent as. Kfactor is a ratio that represents the location of the neutral sheet with respect to the thickness of the sheet metal part. The line where the transition from compression to stretching occurs is called the neutral axis.
Most cad systems that have sheet metal design tools will allow you to input a kfactor that the software uses to calculate the unfolding to give an accurate blank, or flat pattern. A kfactor is a percentage multiplier for locating the neutral axis. Bend allowances are calculated using a k factor as follows. A sheet formed part is usually obtained through a number of operation phases final surface intermediate. In sheet metal, there is a powerful bend constant known as the kfactor. Pdf bend allowance constants for use in sheet metal forming. Jan 27, 2014 sheet metal bending is an important sheet metal manufacturing process. Bending is a manufacturing process that produces a vshape, ushape, or channel shape. Its a mathematical multiplier that allows you to locate the repositioned neutral axis of the bend after forming.
After bending the sheet we need to do some measurements as shown in figure 2. Bending guru steve benson continues his deep dive into the kfactor, arguably the most important variable in precision sheet metal fabrication. Many cad programs, however, also work out bend allowances automatically by using k factor calculations. Actual dimensions can only be found by making the bend and measuring the results. Tool ribbon toolbarattributes step 01 choose the sheet metal attribute button step 02 set up the parameters as follows figure2 sheet metal attribute for kfactor, it. The solidworks application also comes with a kfactor bend table in microsoft excel format. Possible values for kfactor standard is ansi or din radius thickness means radius over thickness. Calculate k factor, bend allowance and y factor for sheet. Analyzing the kfactor in sheet metal bending the fabricator. Prosheetmetal will subtract from the actual length of the material to compensate for the elasticity. Below the image shows how the top of the bend is compressed, and the bottom is stretched. So for a very large radius bend where the neutral axis lies right in the center of the material, the kfactor would be exactly 0.
The main reason that i compared it ti the appearance ui is that it clearly has a standard library, you custom items, and also shows what is unique to the document. The following equation relates the kfactor to the bend allowance. Therefore, it is not part of the standard freecad install. New format of k factor extracting from excel files in. Calculating bend allowance, bend deduction, and kfactor. Then input leg length a and b to get the flat size of the sheet. Im working on a series of sheet metal parts to come up with a kfactor for various thicknesses of sheet metal, and various number of bends.
Of all the mathematical constants used in precision sheet metal fabrication, the kfactor stands out as one of the most important. When you choose the kfactor option solidworks will calculate a bend allowance ba value based on. Value of k factor depends on material, sheet thickness, inside bend radius and machine used. Best way to calculate k factor is to do a simple experiment by cu. For instance you have sm thickness 1mm and you look for a flange of 10mm that means efectively that your bendline should be in a distance from the edge between 8. Sheet metal k factor user modification i also thought about referencing the parameters ui, which would work well also. The strain rate effects on forming limit diagram of sheet metal forming but i want to know the impact of this factor on wrinkling limit of sheet metal forming. How to convert a solid part into sheet metal in solid works. Bending and spring back there are three types of bending, v bending, u bending, and edge bending. Notice that the righthand portion of the dialog box updates to provide an.
As sheet metal parts are flattened or formed if you start with a flat state, prosheetmetal utilizes a y factor to allow for the fact that metal is elastic and stretches as it bends. We started with some sample pieces 6 x 6 in various thicknesses from 16ga to 38 hot roll. Calculated bend allowances are approximate, not exact. Input material thickness and and inner radius to get the data of k factor, y factor, neutral layer. Select rip edges sw automatically selects rip edges. It is necessary to set up a default attribute for sheet metal such as bend radius, kfactor etc. To calculate the bend allowance, the k factor and the derived coefficient called the y factor, insert the thickness and initial length of the sheet into the cells on the left. M p groover, fundamentals of modern manufacturing 3e 20. Accuracy of the finished sheet metal bending product depends entirely upon accurate calculation of bending allowance. Kfactors, yfactors, and press brake bending precision. Since gauge tables were introduced, all the parameters can be controlled base on the drop down selection which makes life much easier. Response to question concerning kfactors by material type and forming method. Folded sheet metal, with bottom added, after correction.
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