THE 2010 ASME STUDENT MECHANISM AND ROBOT DESIGN COMPETITION
More details here: https://forum.solidworks.com/message/143698#143698
Deleting a Row from General Table
02/25/2010This question came up on the SolidWorks Forums today and after answering it I thought of sharing it up.
You have inserted a General table in the SolidWorks drawing and accidentally added one extra Row. Now you want to get rid of that line. As usual you’ll right click on the specific Row you want to remove from the table and clicked on the Delete.
But to your surprise, you can only see the option to delete the entire table and no Row. You may feel bit frustrated with that.
Now here comes the trick to delete the Row from the General Table.
1. Click on Table and you’ll see some thing like in the picture below.
2. Click these small arrows to show the Table Header. (Check, the pointer has changed).
3. Your table should like this.
4. Click on the table again.
5. Select/ highlight the Row (by clicking on the number. See the color change). Now right click on the row number, go to Delete and select Row.
6. Hurray, the unwanted Row has gone. If you want to hide the table header, click on the table again. Now click on those small arrows (look at step 2) again and your header will hide.
Let’s Go Design in 3D
02/17/20102D drafting methods are not able to relay the quality and quantity of design information because 2D methods will always rely on human interpretation or visualization skills to interact with a 2D design. This is always difficult for non design staff and almost impossible for computer systems to extract this kind of information, because computers do not have the ability to interpret.
As a result, many human errors can occur with traditional 2D design methods. In the past problems such as component collisions, incorrect quantities or parts that don’t fit, would happen because a designer who works in only 2D is forced to hold much of the information mentally.
Reducing human error by using the 3D modeling design methods minimizes the need for re-work because the design quality is greatly improved. Using 3D design modeling greatly improves design quality because it is a more complete process than 2D design. One most important thing about 3d CAD design is that people can have view of the model from all possible dimensions. It is a highly detailed drawing of what your concept will look like as a finished product.
Whether you’re designing a new innovative product, creating technical manuals, or requesting quotes from suppliers, 3D CAD design is extremely powerful. But when a 3D CAD design is transformed into a physical 3D print or job shops’ product prototypes, there is no substitute for the tactile and visual feedback a physical model provides to all participants in the design process.
Mechanical Designers usually share their work space with drafters or other engineering technicians in quiet, well-lighted surroundings separated from production areas. Working from drawings, sketches, planning sheets, and other engineering and shop data, tool designers must visualize the Design, do the panning, document and verify every step of the way.
Because of reductions in defense spending, jobs for mechanical engineering type work will decrease; however, the employment of mechanical engineers is expected to grow about as fast as the average for all occupations through this year due to the demand for new and more complex industrial machinery and tools resulting from the development of more sophisticated automated production processes.
The use of 3D modeling technology is essential when you want to develop a superior product. Such a product will not be influenced by human interpretation. Furthermore, it will look like the final model.
The other Solidworks drawings formats.
12/14/2009Detached drawings:
Detached drawings are designed so you can open and work in drawing files without the model files being loaded into memory or even being present.
You can save regular drawings as detached drawings, and vice versa.
With a drawing open, File>Save As. Change the Save as type to “Detached Drawing (*.slddrw)”.
To save the sheet format:
Sheet format files have extension .slddrt and are located in \solidworks\data.
Custom properties in the document are saved with the sheet format and added to any new documents that use the format. Click File, Save Sheet Format You can overwrite standard formats or create custom formats.
Default G codes used on most machines types.
12/09/2009G00 Rapid move G0 X# Y# Z# up to eight axes or G0 Z# X#
G01 Feed Rate move G1 X# Y# Z# up to eight axes or G1 Z# X#
G02 Clockwise move
G03 Counter Clockwise move
G04 Dwell time G04 L#
G08 Spline Smoothing On
G09 Exact stop check, Spline Smoothing Off
G10 A linear feedrate controlled move with a decelerated stop
G11 Controlled Decel stop
G17 XY PLANE
G18 XZ PLANE
G19 YZ PLANE
G28 Return to clearance plane
G33 Threading (Lathe)
G35 Bypass error checking on next line
G40 Tool compensation off
G41 Tool compensation to the left
G42 Tool compensation to the right
G43 Tool length compensation – negative direction
G44 Tool length compensation – positive direction
G49 Tool length compensation cancelled
G53 Cancel work coordinate offsets
G54-G59 Work coordinate offsets 1 through 6
G61 Spline contouring with buffering mode off
G64 Spline contouring with buffering mode on
G65 Mill out rectangular pocket
G66 Mill out circular pocket
G67 Flycut
G68 Mill out rectangular pocket with radius corners
G70 Inch mode
G71 Millimeter mode
G74 Peck drilling (Lathe) G83 Z# X# R#
G81 Drill cycle G81 X# Y# Z# R#
G82 Dwell cycle G82 X# Y# Z# R#
G83 Peck cycle G83 X# Y# Z# R#
G84 Tapping cycle G84 X# Y# Z# R# C#
G85 Boring cycle 1 G85 X# Y# Z# R#
G86 Boring cycle 2 G86 X# Y# Z# R#
G88 Boring cycle 3 G88 X# Y# Z# R#
G89 Boring cycle 4 G89 X# Y# Z# R#
G90 Absolute mode
G91 Incremental mode
G92 Home coordinate reset G92 X# Y# Z#
G94 IPM mode (Lathe) default
G95 IPR mode (Lathe)
G96 Constant Surface Feed On (Lathe)
G97 Constant Surface Feed Off (Lathe)
G110 Lathe Groove Face
G111 Lathe Groove OD
G112 Lathe Groove ID
G113 Lathe Thread OD
G114 Lathe Thread ID
G115 Lathe Face Rough
G116 Lathe Turn Rough
G120 Mill Outside Square
G121 Mill Outside Circle or Island
G122 Mill Out Counter Bore
G123 Mill Outside Ellipse pocket
G124 Mill Inside Ellipse pocket
G125 Mill Outside Slot
G126 Mill Inside Slot pocket
G130 3D tool compensation with gouge protection
G131 3D offset parallel to 3D profile
G132 3D tool compensation with gouge protection in the Z axis only
G135 5 axis tool compensation with gouge protection
G136 Included angle limit for gouge protection. G136 L#
G140 3D part rotation and plane tilting G140 U# V# W# R#
G141 Scale factor for the X axis only. G141 L#
G142 Scale factor for the Y axis only. G142 L#
G143 Scale factor for the Z axis only. G143 L#
G160 Mill 3D Cylinder
G162 Mill 3D Sphere
G163 Mill 3D Ramped Plane
G170 Set soft limits and crash fixture/chuck barriers to defaults
G171 Set backward crash fixture/chuck barriers G171 U# V# W#
G172 Set forward crash fixture/chuck barriers G172 U# V# W#
G181 Bolt Hole Drill
G182 Bolt Hole Dwell
G183 Bolt Hole Peck
G184 Bolt Hole Tap
G185 Bolt Hole Bore
CNC Machining, G codes, G0, Rapid Travel
12/09/2009G0 moves from one point to another point at the maximum traverse rate of the machine. G0 is generally used when cutting will not take place when moving from one location to another.
Multiple axis moves begin by all axes moving together at the same rate until each axis move is completed. This gives the appearance of a forty-five degree move at the beginning of the move. For the remaining distances, each axis will continue to move to the end point.
G0 is modal and will remain in effect until it is canceled by the G1, G2 or G3 codes.
G0 will not cancel any feed rates used by the interpolation modes. An F word can appear on the same line with a G0 code; however, the F word will only be used when an interpolation code is used.
G0 can appear at any point on a line to make all moves on the line rapid.
EXAMPLE:
F30. (This F word is modal).
G0 G90 Z.1 (This line will be in rapid travel).
X1.5 Y2.5 (This line will be in rapid travel).
G1 Z-.25 (The G1 will cancel the G0 and use the F30. from above).
G91 X.5 (This will be at F30.0).
G90 Z.1 G0 (This line will be in rapid travel).
CNC Machining, G codes, G1, Linear Interpolation.
12/09/2009This code is used for linear interpolation. Linear moves can be made by one, or any combination of, all the active axes.
Linear Interpolation is used to generate motion along a line, at a specified feed rate. The linear mode is established by the G1 code.
Some controllers can move up to 5 axes simultaneously, completing the movement at a point determined by the X, Y, Z, A, and B words.
EXAMPLE:
N1 O1
N2 M6 T1
N3 G0 G90 S2000 M3 E1 X0 Y0 A0 B0
N4 H1 Z.1 M8
N5 G1 Z-.25 F5.
N6 G1 G91 X1. F10.
N7 X1. Y1.
N8 X1. Y1. Z1. A360. B90.
According to the sample program above:
Block N6 moves the X axis linearly (G1 mode) 1.0 inch at a feed rate of 10 IPM. Block N7 moves the X and Y axes together forming an angular cut. Block N8 moves all possible axes together.
The G1 code will use the last feed rate established in the program with the F# word. The F# word is modal and is only canceled by another F# word. The F# will remain in effect throughout the program until another F# word is used. The F# word can appear on any line with other codes as long as the other codes have no restrictions. G1 is modal and is only canceled by a G0 code.
The G1 must be used again after using a G0 code in the program. A G2/G3 code will not cancel a G1 code.
This means that if a G2 or G3 is used it is not necessary to re-state the G1 on the following line. Also, if the arc center is not described, then a straight line will be generated.
CNC Machining, G codes, G90 Absolute Input
12/09/2009A control mode in which the motion data input is in the form of absolute dimensions. The values programmed with the axis words are the locations to move to in relation to the current zero position.
Since blocks are processed in a left to right order, both G90 and G91 may appear in the same block. G90 and G91 are position sensitive; therefore the moves to the left of the G90 code will be in absolute until the G91 code is used.
The G90 code is modal and will remain in effect until the G91 code is used.
EXAMPLE:
N12 G90 X2.0 G91 Y1.0 The X move will be absolute; the Y move will be incremental
N13 Z-.02 G5 This Z move will be incremental
N14 G90 X4. This X move will be absolute
APPLICATION OF DOCUMENT AND CHANGE CONTROLS TO DESIGN
12/01/2009The design control system has to be concerned with the creation and revision of documents, as well as the management of finished documents. Additional mechanisms are required to provide needed flexibility while preserving the integrity of design documentation. These additional mechanisms are embodied in the procedures for review and approval of various documents.
It is important that the design change procedures always include re-verifying and re-validating the design. Fortunately, most design changes occur early in the design process, prior to extensive design validation. Thus, for most design changes, a simple inspection is all that is required. The later in the development cycle that the change occurs, the more important the validation review becomes. There are numerous cases when seemingly innocuous design changes made late in the design phase or following release of the design to market have had disastrous consequences.
SolidWorks Virtual Conference: Tips And Tricks Day
11/30/2009SolidWorks Virtual Conference: Tips And Tricks Day
Join us during this one day event and learn how to create more accurate and reliable product designs using SolidWorks.
Participate in our live chat sessions, starting at 1:00pm! Our SolidWorks Experts will be there to answer all your questions, live from the Virtual Conference Auditorium.
To join the SolidWorks Tips and Tricks Day, visit http://www.solidworks.com/innovationday.
*Check out the event agenda
*Download the attendee guide
*Submit your tips
We are looking forward to having you join us online on December 2, 2009, starting at 12pm SGT & 9:30am IST.
The quality assurance model
11/30/2009Introduction
This International Standard is one of three International Standards dealing with quality system requirements that can be used for external quality assurance purposes. The quality assurance models, set out in the three International Standards listed below; represent three distinct forms of quality system requirements suitable for the purpose of a supplier demonstrating its capability, and for the assessment of the capability of a supplier by external parties.
a) IS0 9001, Quality systems- Model for quality assurance in design, development, production, installation and servicing for use when conformance to specified requirements is to be assured by the supplier during design, development, production, installation and servicing.
b) IS0 9002, Quality systems -Model for quality assurance in production, installation and servicing for use when conformance to specified requirements is to be assured by the supplier during production, installation and servicing.
c) IS0 9003, Quality systems -Model for quality assurance in final inspection and test for use when conformance to specified requirements is to be assured by the supplier solely at final inspection and test. It is emphasized that the quality system requirements specified in this International Standard, IS0 9002 and IS0 9003 are complementary (not alternative) to the technical (product) specified requirements. They specify requirements which determine what elements quality systems have to encompass, but it is not the purpose of these International Standards to enforce uniformity of quality systems. They are generic and independent of any specific industry or economic sector. The design and implementation of a quality system will be influenced by the varying needs of an organization, its particular objectives, the products and services supplied, and the processes and specific practices employed. It is intended that these International Standards will be adopted in their present form, but on occasions they may need to be tailored by adding or deleting certain quality system requirements for specific contractual situations. IS0 9000-l provides guidance on such tailoring as well as on selection of the appropriate quality assurance model, viz. IS0 9001, IS0 9002 or IS0 9003.
Concurrent engineering, the name of the game.
11/29/2009Although the waterfall model is a useful tool for introducing design controls, its usefulness in practice is limited. The model does apply to the development of some simpler devices. However, for more complex structures or devices, a concurrent engineering model is more representative of the design processes in use in the industry and is key to success in any industry, where design and manufacturing come together “and stay together” from concept to finished parts, systems, and vehicles, reporting from both the manufacturing and engineering perspectives.
In a traditional waterfall development scenario, the engineering department completes the product design and formally transfers the design to production. Subsequently, other departments or organizations develop processes to manufacture and service the product. Historically, there has frequently been a divergence between the intent of the designer and the reality of the factory floor, resulting in such undesirable outcomes as low manufacturing yields, rework or redesign of the product, or unexpectedly high cost to service the product.
One benefit of concurrent engineering is the involvement of production and service personnel throughout the design process, assuring the mutual optimization of the characteristics of a device and its related processes. While the primary motivations of concurrent engineering are shorter development time and reduced production cost, the practical result is often improved product quality.
SHEET METAL
11/29/2009Article contents:
Sheet metal drawings and fabrication
Characteristics of sheet metal bends
VERY VERY VERY…EXTENSIVE.
Installation FAQs
11/09/2009As the name suggests, this topic covers the SolidWorks Installation FAQs. If you have questions like; what should I do to my system prior to a new installation? Or how do I uninstall SolidWorks from my computer? Or why is it recommended to turn off anti-virus scanning when installing SolidWorks? Then this post is a must read to clear all your doubts. If still you have anything other than covered here, please write back or comment.
Mohr-Coulomb Stress Criterion
10/24/2009The Mohr-Coulomb stress criterion is based on the Mohr-Coulomb theory also known as the Internal Friction theory. This criterion is used for brittle materials with different tensile and compressive properties. Brittle materials do not have a specific yield point and hence it is not recommended to use the yield strength to define the limit stress for this criterion. This theory predicts failure to occur when:
s1 ≥ sTensileLimit if s1 > 0 and s3 > 0
s3 ≥ – sCompressiveLimit if s1 < 0 and s3 < 0
s1 / sTensileLimit + s3 / sCompressiveLimit < 1 if s1 ≥ 0 and s3 ≤ 0
The factor of safety is given by:
Factor of Safety (FOS) = {s1 / sTensileLimit + s3 / sCompressiveLimit} (-1)
von Mises and Tresca Stress Criteria comparison
10/24/2009The maximum shear stress criterion is more conservative than the von Mises stress criterion since the hexagon representing the shear stress criterion is enclosed within the ellipse representing the von Mises stress criterion. For a condition of pure shear, von Mises stress criterion predicts failure at (0.577*yield strength) whereas the shear stress criterion predicts failure at 0.5 yield strength. Actual torsion tests used to develop pure shear have shown that the von Mises stress criterion gives more accurate results than the maximum shear stress theory.
Maximum von Mises Stress Criterion
10/24/2009The maximum von Mises stress criterion is based on the von Mises-Hencky theory, also known as the Shear-energy theory or the Maximum distortion energy theory.
In terms of the principal stresses s1, s2, and s3, the von Mises stress is expressed as:
svonMises = {[(s1 - s2)2 + (s2 - s3)2 + (s1 - s3)2]/2}(1/2)
The theory states that a ductile material starts to yield at a location when the von Mises stress becomes equal to the stress limit. In most cases, the yield strength is used as the stress limit. However, the software allows you to use the ultimate tensile or set your own stress limit.
svonMises ≥ slimit
Yield strength is a temperature-dependent property. This specified value of the yield strength should consider the temperature of the component. The factor of safety at a location is calculated from:
Factor of Safety (FOS) = slimit / svonMises
Understanding the Limitations of a Design Patent
10/23/2009Inventors can obtain three different types of patents in the United States, namely, plant patents, utility patents, and design patents. Plant patents are rare and are used to protect a new plant that the inventor has produced asexually (without using seeds). A utility patent can be used to protect the way a new technology functions and is used. A design patent protects the visual characteristics of an item. There is often confusion among inexperienced entrepreneurs and inventors regarding the differences between utility and design patent protection. It is important to understand that a design patent protects only the appearance of an article and not its structural or functional features. It is different than a utility patent because it offers no protection for the way an article works and can only protect the unique visual “look” of a new item. As such, if you are looking to protect the way your invention works, a utility patent should be pursued. The proceedings relating to granting of design patents are similar to those relating to utility patents with a few differences. A design patent has a term of 14 years from grant, and no fees are necessary to maintain a design patent in force. If upon examination it is determined that an applicant is entitled to a design patent under the law, a notice of allowance will be sent to the applicant or applicant’s attorney, or agent, calling for the payment of an issue fee. The drawing of the design patent conforms to the same rules as other drawings, but no reference characters are allowed and the drawing should clearly depict the appearance, since the drawing defines the scope of patent protection. The claims of a design patent are different from a utility patent. A utility patent has multiple claims while a design patent is limited to a single claim. The drawings of a design patent provide a visual disclosure of the claim. In light of the differences between utility and design protection, it is important that an inventor understand the limitations of a design patent. A design patent should be filed only if the appearance of an invention is important. If it is possible to change the appearance of an invention without significantly altering its function, a utility patent is more appropriate.
John Rizvi is a Registered Patent Attorney at the Fort Lauderdale based law firm of Gold & Rizvi, P.A.-The Idea Attorneys® ( http://www.ideaattorneys.com ).
What is Meshing?
10/21/2009Finite Element Analysis (FEA) provides a reliable numerical technique for analyzing engineering designs. The process starts with the creation of a geometric model. Then, the program subdivides the model into small pieces of simple shapes (elements) connected at common points (nodes). The representation of a given region by a set of elements (i.e., discretization or mesh generation) is an important step in finite element analysis. Meshing the model is the heart of any FEA analysis. The choice of element type, number of elements, and density of elements depends on the geometry of the domain, the problem to be analyzed, and the degree of accuracy desired. Local mesh refinement tools are very important to have good mesh with gradual transitions between the mesh densities. One should have a finer mesh in the areas of high stress gradient to ensure accuracy of the solution.
What is nonlinear analysis?
10/21/2009What are the types of nonlinearities that can occur?In linear analysis, the response of a structure is directly proportional to the load. We assume that:
- the displacements and rotations are small
- stress is directly proportional to strain
- loads maintain their original directions as the structure deforms.
However any of the convenient assumptions that are made during a linear analysis may not hold good in real life situations. For example:
- A contact area may change as the load changes
- A material may no longer exhibit an elastic behavior especially after it starts to yield and flows into the plasticity region.
- The stiffness of the structure may decrease because of buckling or the material may even fracture!
- The displacements and rotations may become too large and thus there is a need to develop equations describing the equilibrium at various intervals instead of one single configuration.
The direction and magnitude of the applied force can change in large rotation problems.
3dcadware
fredvierheller
bob92003
Deepak Gupta