Daily Archives: October 18, 2017

Fillet Brazing vs. TIG Welding Frame

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Brazing, a lower temperature process than welding, uses a bronze rod to create a fillet–a French word for ribbon–pronounced FILL-it (not fill-LAY). It was previously thought higher welding temperatures would ruin good tubing. We now know because welding is faster, the damaging effect of higher temperature is mitigated by shorter heat duration. While disagreements about the relative merits of lower temperature vs. shorter duration continue, a properly fillet-brazed joint will certainly have greater accident “survivability.” For example, if you run into a tree or parked car, a fillet-brazed joint is less likely to fail. Either joint will withstand decades of normal use.

 

Because the bronze fillet is softer than the steel tubing it joins, a skilled craftsman can sculpt a brazed joint without cutting into the tube. Please note that the quality of this sculpting (or craftsmanship) is highly variable–look for large smooth fillets with compound radii and long feathered edges. Beware of “overbite.” Overbite, a result of hurried or sloppy work, is where part of the steel tube has been carelessly filed away at the edge of the fillet. This creates a stress riser that can lead to frame failure. Unfortunately, overbite is a common flaw found on many fillet brazed frames.

Y10R01 CR-MO FILLET BRAZED FRAME

Unavoidable downside of fillet brazing #1: Price.

 

Because fillet brazed construction requires much more time and skill, the price of a properly fillet brazed tandem frame will be $300-$500 higher. If the price differential is lower, inspect the joints carefully before taking delivery. Because of the price, most bicycle customers choose a TIG welded frame.

 

Unavoidable downside of fillet brazing #2: Weight.

 

A filleted joint, like a lugged joint, is slightly heavier than a TIG-welded joint (4oz penalty on a single bike, 12oz penalty on a tandem).

 

Because a properly fillet brazed frame is the ultimate hallmark of a skilled frame builder, the best reason to buy a fillet-brazed frame is because you value the artistry and can appreciate the builder’s skill.

 

If you need more information about fillet brazed frame, I can recommend that you can visit the website of MAXWAY Cycles Co., Ltd… The company is specializing in producing kinds of bike frames such as city bike frames, cyclocross bike frames, fillet brazed frame, MTB bicycle frames, trekking bike frame, etc. More details about bicycle frames, please feel free to send inquiry to MAXWAY.

 

 

Article Source: http://www.gtgtandems.com/tech/brazing.html

The Utilization of Vertical Injection Molding Machines

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When it comes to making items that combine light weight, durability, and pleasing shape, look and feel, there’s nothing that quite matches modern plastics. And this is especially true of hand-held items, such as small electronic appliances, where providing ergonomic shape and a grippy, easy-to-hold surface are particularly important.

 

Whether they’re GPS receivers, medical devices, toys, or even kitchen utensils, the best way to produce such items is through the process of over molding. It involves the molding of two different plastics, one on top of, or around, the other, so as to produce what amounts to a single, unified structure that’s strong on the inside yet flexible, colorful, and easy to hold on the outside.

 

Benefits of over molded plastics devices include:

 

  • More Resistant To Shock
  • More Resistant To Water
  • More Resistant To Dust And Vapor
  • More Resistant To Vibration
  • Make Devices More Comfortable To Use
  • Make Devices Just Plain Prettier

 

By now, over molding is a standard process in the injection molding industry, but some methods of executing the process is superior to others. The challenge is to make sure the two pieces, rigid substrate and outer elastomer, to fit together just so, with no gaps, no slack, no possibility of slippage and with no chance of one part pulling on and distorting the shape or integrity of the other. Getting these two molded parts to match up just right takes a good deal of skill and experience. No adhesives can be used, and there should be no manual assembly steps involved, either – it’s mainly a matter of making molds that create a perfect fit and then performing the actual molding process with extreme precision.

 

And it’s here that the right machinery also helps a great deal. Indeed, the best way to produce over-molded parts is with a vertical injection molding machine. It relies on the gentle force of gravity to clamp the inner and outer parts together.

 

That’s different from a horizontal injection molding machine, which relies on mechanical clamping, a method that requires more time and effort and raises the risk of improper fit: Gravity’s pull is always there, always trying to dislocate parts in a horizontal mold. The vertical mold simply takes advantage of gravity instead of trying to fight it.

 

Vertical injection molding equipment is designed with open clamps and rotary tables, which gives them the advantage of being able to work with multiple molds and simultaneous operations such as pre-molding, injection-, and post-molding. The result: less need for manual intervention, greater efficiency, greater productivity, and less cost. What’s more, vertical molding machines often save significant space on the factory floor.

 

In short, vertical injection molding is the method of choice when it comes to producing high-strength, high-touch parts for the electronics, medical, military, and similarly demanding industries.

 

More information about vertical injection molding machine, try to visit the website of Multiplas Enginery Co., Ltd... Multiplas is a leading industrial solutions provider that offers versatile moulding solutions, innovative design and manufactures for the production systems, and provides comprehensive technical support services to the customers committed in 3C electronics, electrical, automotive, medical / optical, and other technical moulding sectors. If you have any interest, please feel free to send inquiry or contact them directly.

 

 

Article Source: http://info.crescentind.com/blog/bid/40004/Over-molding-and-the-utilization-of-vertical-vertical-injection-molding-machines