Basic CAD for New Product Idea Innovators

1- Digital technology has done as much for the engineering industry as it has for communications.

2- I wasn’t so old during the second half of my career that I couldn’t see the value of 3-D modeling and see that it was there for engineers, not only designers.

3- Instant preliminary-design results easily showed us what we should pursue and what we shouldn’t.

4- Solid Works was as intuitive as getting on a bicycle the first time.

5- It was expensive for a seat and maybe much more than needed for home use.

6- Free 3-D software is available from other companies for downloading.

7- Naturally, they can’t match the performance of Solid Works, but they don’t have to. I don’t want to recommend any.

8- My biggest concern is although my heart is in the right place, my computer system knowledge may not be.

9- I’ve stopped downloading anything that I’m not paying for. Crap happens and there goes another $150.

10- Visiting YouTube is a good place to start if looking for demo videos, which is the only way to start out. Try 3D modeling for beginners.

11- 3D modeling has always been about first defining one surface of a part.

12- With that, the part can be extruded into the third dimension turning the part into a solid model, one that has three-dimensional definition, both externally and internally.

13- After that, features are added to the surfaces using 2d definition to form a 3d feature after extruding.

14- Extruding can add material or subtract material.

15- Individual files can be compiled into an assembly where the parts can be moved around and fixed relative to one another, as in an assembly drawing.

16- The software generates files (stl.) that can be used for 3d printing or CNC machining of the product idea parts.

17- Below, the sketch planes shown are Figures 1,3,5 and 7. The extrusions are Figures 2,4,6 and 8.

18- 3D modeling is a fantastic technology, and all innovators have the aptitude to adopt and utilize it quickly.

19- Stop and examine your sketching habits sometime. You'll find they are very similar, if not the same as CAD logic.

If you follow this sequence of illustrating the development of a piece part, you'll be a natural for 3d Modeling.

Basic CAD for New Product Idea Innovators

"CAD did for innovation what the automobile did for cross country trips." 

Plastic Parts for Modern Product Concepts 

530 words

It wasn't too long ago that plastic was considered cheap. There weren’t hundreds of polymers then and the option of having glass-filled parts wasn't on the table. Who would have ever thought of chrome plated plastic parts, the product not only being attractive, but almost as resistant to abuse and fatigue as die cast metal parts? Now, with EDM (Electronic Discharge Machining), mold cavities can be created in 1/10 the time it once took tooling professionals to machine a mold cavity. Also, with multi-cavity tools, the parts from each cavity are identical. 
 
Family molds are multi-cavity only in the sense there are more than one cavity. Each cavity is for different related parts, allowing in many cases all the parts of a product to be injection molded from one mold. This saves up-front money when building the mold.

Ninety-five percent of consumer product design is plastic oriented. Most product parts come from multi-cavity injection molds; the same part being replicated in each cavity.
 
Each time the mold is filled with a thermoplastic or thermosetting polymer, more than one part is produced, keeping the piece part cost down, but on the other hand requiring the investment of one mold for each piece part. Adding glass fibers to the polymers is very cost-effective because of the value of the increased strength. Non-family molds allows a change in material and color for each part which isn't cost effective or likely possible with a family mold. Which way to go comes down to how many of the new product will be sold, larger numbers allowing more flexibility with manufacturing processes, such as injection molding.

Scrutinizing computer models of the concept piece parts by product designers  and engineers  always eliminates expensive tooling changes that might occur when the product is rushed into piece part manufacturing. Every dimension of every piece part in all products have tolerances that must be considered for assembly and function. Tolerances allow the mold designers a reasonable amount of latitude with each part specification. Naturally, tolerance accumulation must be considered by the product designer. Piece parts need to assemble problem free and function problem free. Tool designers must be versed in product design and product designers must design for manufacturing as well as the product customer. 
 
Changes to injection molds can be expensive, especially when more than one cavity is involved. Rework charges are never included in development cost budgets and must be absorbed with sales. Experience and respect for all manufacturing processes is a plus for any product design service. Designing parts that don't require adding complicated features to the mold, such as side actions, should be expected of any product design service.

All types of injection molded hand tools for shop and home should be market tested in one way or another before investing in tooling. A sense of quality is important.  Along with product designers spending many hours perfecting the parts for manufacturing, the combination of both can be expensive. This is not a problem if thousands of product assemblies are going to be sold. A product design service has no control, other than offering quality, over how many units will be sold.

Aluminum Die Cast Parts in  Product Design

856 words

The choice of product design and engineering professionals for manufacturing woodworking tools and fixtures are alloys such as aluminum and zinc, two of the best non-ferrous materials for the die casting of thin wall product parts. Combinations of those alloys are used as well.  When a product must be robust to the point it can withstand more functional force than needed, yet light enough to prevent fatigue and accidents when being used, aluminum or zinc die cast parts are the alternative over thin wall aluminum extrusions and the injection molding of plastic parts with a glass-filled polymer. The parts being able to withstand reasonable heat enters the equation as well.​​

The innovative dovetail jig shown here is a good example. The jig is intended to clamp to project boards securely held in a bench vice. It must be repositioned for each router cut, suggesting it doesn't want to be heavy and difficult to move. Yet it must be robust enough to withstand excessive clamping forces that might bow the base, which would cause unsatisfactory machining results.
 
Die cast parts are rarely solid in cross-section. Solid cross sections lead to unwanted weight, excessive material, and sink marks caused by non-uniform cooling of the part. The cross sections of the parts are usually designed with uniform wall thicknesses. Many ribs projected ninety degrees from the main surface walls provide more than sufficient strength. Optimizing all cross sections comes from the experience of the engineer as well as from proven and tested finite element computer programs. All die cast parts have draft on any surface that must be pulled from the confines of a cavity. The part walls look parallel but are not. A home example is a tray of ice cubes. With outside taper, the ice cubes can be dumped out. It's important to hire an engineering and design service that has proficiency in molding and casting technology.

Die cast parts, like injection molded parts, should be designed and engineered so they can be ejected from the molds with only one action, the opening of the mold.  Undercuts in piece part design usually result in additional slide actions, which can be costly with the construction of the dies, especially multi-cavity dies. Higher tooling costs can be absorbed with high volume products that might run for several years or more. With low volume parts, an engineering and design service should strive to keep piece parts free of features that require slides. or what the profession calls action.

Where threads are needed, steel inserts can be inserted into the die between cycles for the aluminum to flow around and capture, or the knurled inserts can be pressed into the piece part at a later stage. Parts must be ejected from die cavities with push pins. The pins will always produce a footprint, usually under the part. They are always round and not very deep. The feed gate, or the entrance of the molten aluminum into the die cavity usually must be machined off after ejection of the part.

All plastic molded and die cast parts of all processes have flash, material that flows between tool halves, each side of the parting line. When it exceeds the specification, it must be removed. Tumbling deburring is a process used to do this. The process can also be used to enhance the surface finish of the part. If the flash is excessive, it must be machined off as a secondary operation.

 Secondary operations, whether intention or not, are costly and in many cases requires  the design and construction of fixtures.  With modern mold making technology, die castings can have a smooth surface that otherwise might be expected from only aluminum plate or extrusions. Burning of the cavity instead of machining them produces smooth cavity walls that in turn transfers to smooth surface piece parts.

Very fine detail should always be discussed with the molder. This is something the product design service can't assume they can automatically have.  The molten aluminum, even under pressure,  can't always fill tight volumes with the same performance as polymers, although the fill capability is above other lower cost casting alternatives, such as sand castings. 

Products not only have to be innovative, but the processes also to produce them need to be as well, especially with challenging cost goals. 
Die cast parts do not accept anodizing to the degree of satisfaction aircraft aluminum does. Often, die cast parts can have an intentional rough surface, providing adequate draft is provided,  that accepts paint applications. After painting, working surfaces of the tool or jig are machined flat, and left free of paint. This is a process used with large parts from sand cast moldings.

Aluminum alloys used for diecasting are usually formulated with a small amount of zinc and magnesium that adds strength and improves flow characteristics of the alloy. Naturally, engineering data is available for choosing the best formula for any product application.