Original design
Nested layout of the original design
By suitably redesigning the work table as shown below, part utilization increased from 4 part nesting to 6 part nesting in the same sheet and scrap is avoided.
Fully Automatic True Shape Nesting Technology from Geometric
Monday, February 22, 2010
Redesign your components for cost reduction
A work table design modeled as shown below ended up with a nested layout involving lot of scrap.
Original design
Click here for a Nestlib Evaluation copy
Original design
Sunday, October 25, 2009
Methods and Issues in Determining Material Cost for Sheet Metal Parts
Cost of a sheet metal part comprises three major cost components such as material cost, processing cost and overheads. Determining accurate material cost has always been an issue. Theoretically material cost can be calculated as follows:
Material Cost = Area of the flat pattern*thickness*(weight per unit volume)*cost per unit weight.
But this is not a correct estimate as the flat pattern has to be cut from a standard sheet and scrap will be generated while cutting as well as due to the shape of the part. So, various methods are employed by costing professionals to estimate material cost that includes scrap cost. Considering thickness, weight per unit volume and cost per unit weight as constant, part area that accounts for scrap is calculated as follows:
1. Part Area = 1.2 times area of the flat pattern
2. Part Area = Area of the bounding box that encloses the flat pattern
3. The part under consideration is nested in a standard sheet and multiple quantities of same part are nesting. The quantity of the part is selected to fill the entire sheet.
Part Area = A*As/n*A,
Where A - Area of the flat pattern,
As - Area of sheet excluding remnants and
n is the quantity or number of parts nested in the standard sheet.
4. In few other cases, all the parts in an assembly having same sheet thickness are nested in standard sheet with a predetermined lot size.
Part Area = Ai*As/Σ(ni*Ai),
Where Ai - Area of the flat pattern of the ith part,
As - Area of sheet excluding remnants and
ni is the quantity of the ith part nested in the standard sheet.
Methods 3 and 4 are more accurate than methods 1 & 2. If the nesting software is more efficient enough as that of Nestlib, then the nesting software can automatically determine whether method 3 or 4 gives better utilization. Nestlib's optimizer module does this magic. Another important factor is sheet selection as utilization depends on the sheet size used. So, costing will further be more efficient if we can determine the optimal sheet size that gives maximum utilization. This task can also be performed automatically by inventory forecasting module of Nestlib. Even with all these above methods, we can only get a near accurate cost because the nested layouts at design stage involve only the particular part/assembly. Manufacturing might use a different nested layout involving other parts/assemblies. For a contract manufacturer, the nested layouts might even involve parts from different clients. But for costing, nested layouts at the design stage form a baseline for cost estimation and dictates a minimum utilization to be achieved during manufacturing.
i.e. if an utilization of 75% is achieved in design and an utilization of 85% is achieved in manufacturing, then it is acceptable. But if an utilization of 70% is achieved in manufacturing due to other assemblies, then manufacturing should use the nested layout given by design.
Material Cost = Area of the flat pattern*thickness*(weight per unit volume)*cost per unit weight.
But this is not a correct estimate as the flat pattern has to be cut from a standard sheet and scrap will be generated while cutting as well as due to the shape of the part. So, various methods are employed by costing professionals to estimate material cost that includes scrap cost. Considering thickness, weight per unit volume and cost per unit weight as constant, part area that accounts for scrap is calculated as follows:
1. Part Area = 1.2 times area of the flat pattern
2. Part Area = Area of the bounding box that encloses the flat pattern
3. The part under consideration is nested in a standard sheet and multiple quantities of same part are nesting. The quantity of the part is selected to fill the entire sheet.
Part Area = A*As/n*A,
Where A - Area of the flat pattern,
As - Area of sheet excluding remnants and
n is the quantity or number of parts nested in the standard sheet.
4. In few other cases, all the parts in an assembly having same sheet thickness are nested in standard sheet with a predetermined lot size.
Part Area = Ai*As/Σ(ni*Ai),
Where Ai - Area of the flat pattern of the ith part,
As - Area of sheet excluding remnants and
ni is the quantity of the ith part nested in the standard sheet.
Methods 3 and 4 are more accurate than methods 1 & 2. If the nesting software is more efficient enough as that of Nestlib, then the nesting software can automatically determine whether method 3 or 4 gives better utilization. Nestlib's optimizer module does this magic. Another important factor is sheet selection as utilization depends on the sheet size used. So, costing will further be more efficient if we can determine the optimal sheet size that gives maximum utilization. This task can also be performed automatically by inventory forecasting module of Nestlib. Even with all these above methods, we can only get a near accurate cost because the nested layouts at design stage involve only the particular part/assembly. Manufacturing might use a different nested layout involving other parts/assemblies. For a contract manufacturer, the nested layouts might even involve parts from different clients. But for costing, nested layouts at the design stage form a baseline for cost estimation and dictates a minimum utilization to be achieved during manufacturing.
i.e. if an utilization of 75% is achieved in design and an utilization of 85% is achieved in manufacturing, then it is acceptable. But if an utilization of 70% is achieved in manufacturing due to other assemblies, then manufacturing should use the nested layout given by design.
Saturday, September 26, 2009
Automatic Remnant Determination
Nowadays business is highly competitive and manufacturing firms are looking for ways and means to reduce cost at each and every stage. Reducing scrap is an important activity, which can result in considerable cost saving. Given a set of parts, It is always not possible to use the entire sheet. For example, in a sheet size of 48"x72", the parts may occupy only a portion of the sheet as shown in the figure below.
Nested LayoutThe usable remaining sheet, gray shaded area in the nested layout is called remnant sheet and can be used for nesting parts in the next manufacturing run. From nested layouts, determining such remnant sheets is generally a manual activity. Nestlib provides options to determine remnant sheets automatically. Various remnant shapes like rectangular remnant, stepped remnant, true shape remnant can be determined.
Rectangular Remnant
Stepped Remnant
True Shape Remnant
Wednesday, August 19, 2009
Automatic sheet selection for nesting
Given a set of parts, selecting a right sheet size manually is always a menace to the manufacturing engineers. Because, material utilization for the same set of parts on different sheet sizes are not same. Further, there are other challenges faced by manufacturing engineers such as
1. Sheet selection from standard sheets
2. Sheet selection from standard sheets as well as Remnant sheets
3. Combinatorial sheet selection
4. Unique sheet selection
Given all such challenges, manual sheet selection would prove laborious and inefficient in selecting the optimal sheet. Very often manufacturing engineers settle for sheets with suboptimal material utilization, which increases scrap and thereby increases manufacturing cost. With the present day need for cost cutting, these are potential problems that can be easily addressed by automating the sheet selection process. Nestlib's inventory forecasting module provides such an automated sheet selection option.
1. Sheet selection from standard sheets
Standard sheets sizes such as 48"x72", 60"x72", 72"x72", 72"x144", 96"x144", etc., are commercially available. Manufacturing engineers have to choose a sheet with maximum material utilization from these standard sheets, which requires lot of iterations. Nestlib can automatically choose the right sheet for a given set of parts.
2. Sheet selection from standard sheets as well as Remnant sheets
In certain manufacturing runs, the nested layout for a given set of parts may not consume the whole sheet. In such cases, the remaining sheet, which is called as remnant sheet is generally used for nesting the next lot of parts. Sheet selection task can get more complicated when remnant sheets from previous manufacturing runs are also to be analyzed for utilization. For a given set of parts, Nestlib can choose the right combination of standard sheets as well as Remnant sheets. Nestlib can also give remnant sheets automatically for each nested layout, which can be used for nesting in consequent manufacturing runs.
3. Combinatorial sheet selection
As multiple standard sheet sizes are available, a combination of various sheet sizes for a given set of parts may lead to maximum material utilization. For example,it might turnout profitable to select 2 numbers of 48"x72" sheets and one 72"x144" sheet for a given set of parts. Nestlib provides such a combinatorial sheet selection which automatically selects a combination of various sheet sizes with maximum material utilization as the decision criteria. Nestlib includes remnant sheets also in such combinatorial selection.
4. Unique sheet selection
Sometimes it may be necessary to nest in same sheet sizes. For manufacturing large lot sizes, identical layout in same sized sheets will render use of same die, which will reduce setup time and tooling cost. The problem is to identify the unique sheet size from among the standard sheet sizes. For example if a set of parts need 50 numbers of 48"x72" sheets and 30 numbers of 72"x144" sheets, it may be profitable to nest all the parts in either 48"x72" sheets or 72"x144" sheets depending on maximum material utilization. Nestlib offers such unique sheet selection as well, where nesting is performed on same sheet size for all the parts and the unique sheet size that gives maximum material utilization is selected.
1. Sheet selection from standard sheets
2. Sheet selection from standard sheets as well as Remnant sheets
3. Combinatorial sheet selection
4. Unique sheet selection
Given all such challenges, manual sheet selection would prove laborious and inefficient in selecting the optimal sheet. Very often manufacturing engineers settle for sheets with suboptimal material utilization, which increases scrap and thereby increases manufacturing cost. With the present day need for cost cutting, these are potential problems that can be easily addressed by automating the sheet selection process. Nestlib's inventory forecasting module provides such an automated sheet selection option.
1. Sheet selection from standard sheets
Standard sheets sizes such as 48"x72", 60"x72", 72"x72", 72"x144", 96"x144", etc., are commercially available. Manufacturing engineers have to choose a sheet with maximum material utilization from these standard sheets, which requires lot of iterations. Nestlib can automatically choose the right sheet for a given set of parts.
2. Sheet selection from standard sheets as well as Remnant sheets
In certain manufacturing runs, the nested layout for a given set of parts may not consume the whole sheet. In such cases, the remaining sheet, which is called as remnant sheet is generally used for nesting the next lot of parts. Sheet selection task can get more complicated when remnant sheets from previous manufacturing runs are also to be analyzed for utilization. For a given set of parts, Nestlib can choose the right combination of standard sheets as well as Remnant sheets. Nestlib can also give remnant sheets automatically for each nested layout, which can be used for nesting in consequent manufacturing runs.
3. Combinatorial sheet selection
As multiple standard sheet sizes are available, a combination of various sheet sizes for a given set of parts may lead to maximum material utilization. For example,it might turnout profitable to select 2 numbers of 48"x72" sheets and one 72"x144" sheet for a given set of parts. Nestlib provides such a combinatorial sheet selection which automatically selects a combination of various sheet sizes with maximum material utilization as the decision criteria. Nestlib includes remnant sheets also in such combinatorial selection.
4. Unique sheet selection
Sometimes it may be necessary to nest in same sheet sizes. For manufacturing large lot sizes, identical layout in same sized sheets will render use of same die, which will reduce setup time and tooling cost. The problem is to identify the unique sheet size from among the standard sheet sizes. For example if a set of parts need 50 numbers of 48"x72" sheets and 30 numbers of 72"x144" sheets, it may be profitable to nest all the parts in either 48"x72" sheets or 72"x144" sheets depending on maximum material utilization. Nestlib offers such unique sheet selection as well, where nesting is performed on same sheet size for all the parts and the unique sheet size that gives maximum material utilization is selected.
Sunday, July 5, 2009
Do we need need nesting in the Design Stage itself?!$
Yes, We need nesting solution in the design stage itself for optimal part design with maximum material utilization thus reducing the product cost.
1. If we have a nesting utility in the design tool itself, the designer can nest the part(s) and check his design immediately for material utilization and redesign suitably to improve material utilization. Design modifications done at an early stage are less penalizing and eliminates costly and often iterative design modification/change process.
2. Nesting at the design stage also helps to design parts to suit standard coils rather than sheets, which will reduce the manufacturing cost.
3. Nesting at the design stage is helpful to identify the right sheet size and the quantity early, thus expediting raw material purchase.
4. Nesting integrated with a modeler helps contract manufacturers to estimate the sheet metal product cost accurately to give a competitive quote, thus increasing the possibility of winning the contract.
5. Nesting integrated with a modeler can help in Should Costing as well, to calculate accurate costs and to negotiate for better prices.
1. If we have a nesting utility in the design tool itself, the designer can nest the part(s) and check his design immediately for material utilization and redesign suitably to improve material utilization. Design modifications done at an early stage are less penalizing and eliminates costly and often iterative design modification/change process.
2. Nesting at the design stage also helps to design parts to suit standard coils rather than sheets, which will reduce the manufacturing cost.
3. Nesting at the design stage is helpful to identify the right sheet size and the quantity early, thus expediting raw material purchase.
4. Nesting integrated with a modeler helps contract manufacturers to estimate the sheet metal product cost accurately to give a competitive quote, thus increasing the possibility of winning the contract.
5. Nesting integrated with a modeler can help in Should Costing as well, to calculate accurate costs and to negotiate for better prices.
Tuesday, May 19, 2009
Geometric's NestLib
True Shape Nesting technology from Geometric
NestLib is an automatic nesting software for optimizing material utilization while fitting two-dimensional shapes on a larger sheet. NestLib incorporates several features which result in significant material saving. NestLib is one of the fastest and most featured automatic true shape nesting library available in the industry.
Why NestLib? NestLib increases productivity
- Achieves entire nesting in just a few seconds
- Contributes in completely automating the production line
NestLib saves material (Need of the Day)
- Provides highly optimized and compact layout, thus reduces raw material consumption
- Reuse of waste material
- Predicts inventory requirement
NestLib is easy to integrate
- Quickly integrates with your existing system or product in less than 5 days
- Minimal programming knowledge required
NestLib can be used in the following industries
- Sheet metal industry
- Machine tools/machine manufacturers
- Companies providing CAD/ CAM solutions
- Leather industry
- Wood working/cabinet making industry
- Construction industry
- Printing industry
- Engraving/sign making industry
- Agricultural equipment manufacturers
- Automotive and aircraft industry
- Shipping industry
- Packaging industry
- Dental industry
- Pipe cutting
- Facility layout / space planning
- Product display planning in retail industry
- PCB industry
- Granite/marble/glass/plastic industry
Modules in Nestlib
- Automated True shape Nesting
- Rectangular Nesting
- Strip nesting
- Speed Nesting
- Shear Cutting
- Common Punch Nesting
- Common Flame Cutting
- Remnant Plate Generation
- Leather Nesting
- Automatic Pairing and Clustering
- Grid Fit
- Multiple Torch
- Master Plates
- Adaptive Nesting
- Inventory Forecasting Module
- Cutting Sequence Generation
Subscribe to:
Posts (Atom)