Sheet metal is an external workbench evolved to design and unfold sheet metal parts. When you select kfactor as the bend allowance, you can specify a kfactor bend table. It is used to calculate sheet metal flat length flatpattern. We produce a lot of sheet metal work using invento and use 0. In my previous post i talked about kfactor, bend allowance and bend deduction and what they mean in sheet metal design. When a piece of metal is being formed, the inner portion of the bend compresses while the outer portion expands see figure 1. And, you have all the dimensions of the final component in your design. Demonstrate to employers that you understand the set of solidworks tools that aid in the design of sheet metal components by completing the certified solidworks professional advanced sheet metal cswpasm exam. Relationship between bend deduction, bend allowance, and k factor. Suppose that you have designed a sheet metal component for fabrication. The kfactor is the ratio between the the neutral axis to the thickness of the material.
This can lead to a lot of confusion and errors when designing and calculating flat patterns. The kfactor is nothing more than a multiplier that can give you an accurate value for the relocated neutral axis. The kfactor is defined mathematically as tmt, where t is the neutral axis location and mt is the material thickness. Cut a sample sheet and measure its total flat length and sheet thickness in mm. Kfactors are a great tool for developing flat blanks for sheet. 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. In this article we will discuss sheetmetal bend deduction, bend allowance, kfactor, yfactor and sheet metal flat pattern calculations. As there is no special support for it in freecad, it tends to take time to design sheet metal parts, as i need to manually add sketches, extrude walls, and add fillets. When you bend sheet metal, the neutral axis shifts toward the inside. Learn what a kfactor is in sheet metal forming, learn how kfactor is used, and learn how to calculate kfactor in this video.
Design for manufacturability sheet metal guidelines bends for the ease of manufacturing, multiple bends on the same plane should occur in the same direction. Me is a community and comprehensive knowledge base for the engineering design and fabrication of sheet metal. Steel kfactor pressbrake forming solidworks forums. The k factor is the most important and elusive variable of bending, because it varies both as a function of the material and according to parameters such as angle and tooling. In sheet metal design, the kfactor is used to calculate how much sheet metal one needs to leave. In low carbon steel sheet metal, the minimum radius of a bend should be one. Because of the specific properties of any given metal, there is no easy way to calculate that value perfectly, hence the chart in figure 2. The kfactor is fundamental to designing precise sheet metal products. You can specify an explicit bend allowance or bend deduction for any sheet metal bend by entering the value when. Therefore, it is not part of the standard freecad install.
Just like ba and kfactor, sheet metal bend deduction is also a very crucial part of sheet metal design terminology. Sheet metal fabrication ranges from deep drawing, stamping, forming, and hydro forming, to highenergyrate forming herf to. So for a very large radius bend where the neutral axis lies right in the center of the material, the k factor would be exactly 0. Let me make it clear that it is a very important term used in sheet metal design. Kfactor is a ratio that represents the location of the neutral sheet with respect to the thickness of the sheet metal part. If you design your bent sheet metal parts in cad software that has a special sheet metal environment, use it. Design methodologyapproach a dummy 3d cad model of the assemblies has been made using assembly.
Calculate k factor, bend allowance and y factor for sheet metal. The kfactor is fundamental to designing precise sheet metal. How to set up sheet metal gauge tables engineers rule. Cad tools use kfactor to calculate sheetmetal blank size. Calculate k factor, bend allowance and y factor for sheet.
Sheet metal operationpart 1sheet metal design series. Avoid large sheet metal parts with small bent flanges. Duct system design guide first edition 2003 mcgill airflow corporation mcgill airflow corporation one mission park groveport, ohio 43125 duct system design i notice. No part of this work may be reproduced or used in any form or by any means graphic, electronic, or. Calculating bend allowance, bend deduction, and kfactor.
As explained in bend allowance, when sheet metal is bent, the inside surface of the bend is compressed and the outer surface is stretched, but somewhere within the thickness of the metal lies its neutral axis, which is a line in. Best way to calculate k factor in sheet metal is by reverse engineering. Kfactors, yfactors, and press brake bending precision. We are actually in the process of dialing in our solidworks sheet metal properties to match the brakematerial we are using. Our sheet metal design will use the following specifications. In sheet metal, the kfactor is the ratio of the neutral axis to the material thickness.
Many cad programs also work out bend allowances automatically by using kfactor calculations. Well, when a sheet is bent in the press brake, the part of the sheet close to and in contact with the punch elongate to compensate for the given bend if you compare the length of this part, before and after the bending, youre going to find that theyre different. You may be wondering what exactly is bend allowance if youve never worked with sheet metal before. You can also use our flat pattern calculator for blank size calculation. Analyzing the kfactor in sheet metal bending the fabricator. When metal is bent the top section is going to undergo compression and the bottom section will be stretched. It ultimately allows you to estimate the amount of stretch without knowing what type of material you are bending. Here is an equation for the kfactor given by solidworks in the help file for bend calculation table, with no explanation. You can use this kfactor calculator to calculate k factor using reverse engineering method. To achieve the cost control and reduced design iterations and testing with physical prototypes, we deliver highquality sheet metal parts. Sheet metal design with the booming need to enhance the product quality and finishing, testing different metallurgy at affordable cost, sheet metal fabricators demand accurate fabrication drawings. How to use this kfactor calculator in sheet metal reverse engineering approach step1. Sheet metal basics sheet metal interview questions for. We use 18 gauge 316 stainless steel, our solidworks is set to.
Then learn how to create basic parts, with base features, flanges, and bends that add strength and connections. If you follow the design advice and maintain the tolerances expressed in this article, you are more likely to end up with parts. As i mentioned in my last post you need to do some tests to calculate these values for a specific sheet. Our pages on fabrication formulas, tooling terminology, and gage charts are references for the industrys engineers. In the improved design, the sheet metal only needs one bending process to complete the bending of the two sides at the same time. Continuing our focus on sheet metal forming, this issue of dfm guidebook focuses on design guidelines for bend relief parameters, distance between holes and bends and offset bend material when a bend is made close to an edge.
When making bends, it takes material specifications into account. Therefore, when sheet metal has complex bends, consider splitting a complex bend into two parts. Importance of the kfactor in sheet metal design the kfactor is used to calculate flat patterns because it is related to how much material is stretched during bending. Bend deduction explained with formula and calculator. What are bend allowance, bend deduction and kfactor. Then run your bend calculations using a kfactor that takes your. This comprehensive suite of creo sheet metal design tools helps users create features such as walls, bends, punches, notches, forms, and relief features. The kfactor in sheet metal working is the ratio of the neutral axis to the material. Once you know the kfactor, you can use it to predict the bend allowance for various angles. Design for manufacturability sheet metal guidelines. Now, you may be thinking, where this k factor is used. At form2000, we have a sheet metal engineering suite in our factory in melbourne, and we are equipped with 3d design and simulation software, which enables our team of expert engineers to reach the optimal machine selection and order of operations required to efficiently manufacture your sheet metal product.
The kfactor in sheet metal working is the ratio of the neutral axis to the material thickness. Sheet metal is used in the production of materials ranging from tools, to hinges, automobiles etc. It allows you to anticipate the bend deduction for a large variety of. Similarly, the more complicated the sheet metal bending process, the more material waste may be caused. And if you know the bend allowance, you can extract the kfactor from it. The sheet metal model built with the sheet metal addon rear. Bend the sheet to 90 degrees and measure length a and b. We will start by creating a simple sheet metal design with a threeline sketch.
Simple threeline sketch to test our sheet metal gauge tables. In sheet metal, there is a powerful bend constant known as the k factor. Now lets see how we can obtain these values for a specific sheet. Using a variety of y and k factor bend allowance calculations, designers can create flat patterns of the designs. All this information is necessary when making a flat pattern for laser cutting. Sheet metal k factor what is it and how to measure it solidworks duration. Kfactor calculator for sheet metal bending smlease design. Since the inside compression can not exceed the outside tension, the kfactor can never exceed. Our design guidelines are a good starting point for new or experienced designers looking to make sure their ideas will be able to be effectively manufactured. The k factor in sheet metal working is the ratio of the neutral axis to the material thickness. Kfactor is actually the ratio of the offset t of the neutral axis from the inside bend and the thickness of the sheet t when a piece of sheet metal is bent. Bending a known length of sheet metal is easy, but to calculate the bend. Below are some tips and guidelines for designing sheetmetal parts.
Hence all of the sheet metal designing software use kfactor, in order to provide an accurate design of the flat pattern of the sheet metal component. Hybrid design we can now create wireframe and surface features within the same. The following illustration shows a and b, used to calculate the bend allowance. It is used to calculate bend allowance and bend deduction which are further used to calculate the flat pattern. Design surface part as designed to fit in the car after trimming blankholder surface.
Bending is a manufacturing process that produces a vshape, ushape, or channel shape. Bending calculations using kfactor, bend deduction, and bend allowance. Having an accurate idea of your kfactor is key to designing good parts. Sheet metal addon for freecad open source cad software.
The k factor can be customized by excel spreadsheets and the bend radius can be set after the part has thickness by editing the sheet metal feature in the browser bar. Calculate k factor, bend allowance and y factor for sheet metal bending. Sheet metal fabrication plays an important role in the metal manufacturing world. A sheet formed part is usually obtained through a number of operation phases final surface intermediate. The setback chart is a quick way to find the setback and is useful for open and closed bends, because there is no need to calculate or find the kfactor. In this article we will discuss sheetmetal bend deduction, bend allowance, k factor, y factor and sheet metal flat pattern calculations. Please note the bending of sample part is done in the same manner as we are planning for production. Therefore it is important to have the value correct in cad software. If you noticed there is no library of material for the k factor and you were not prompted for the bend radius. Kfactor is a ratio that represents the location of the neutral line with respect to the thickness of the sheet metal. 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.
Most cad systems that have sheet metal design tools will allow you to input a k factor that the software uses to calculate the unfolding to give an accurate blank, or flat pattern. Solidworks sheet metal tools are relatively straight forward, but may not be clearly understood. We are now ready to use these sheet metal gauge tables. If you design sheet metal parts, you may know that bend relief is a notch cut made into the. The solidworks application also comes with a kfactor bend table in microsoft excel format. Sheet metal unfold rule equations ketiv technologies.
First of all, let me explain why and where you need to use this bend deduction. Mathematically k factor value is equal to the ratio of position of neutral axis and sheet thickness. In sheet metal, there is a powerful bend constant known as the kfactor. We are just starting on this project so we use the same diesbend radii for all parts. Pdf the study of design constants in sheet metal forming. Bending calculations using kfactor, bend deduction, and.
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