June 16, 2020 Volume 16 Issue 23

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Self-lubricating polymers improve surf machines

A company in Brazil that designs fitness training equipment that simulates the movements of a surfboard reduced costs by 70 percent by switching to bearings manufactured by igus, the Germany-based motion plastics expert. The bearings also cut down on maintenance significantly.
Read the full article.


CNC machining for prototypes or low-volume parts

For plastic parts, CNC machining allows you to test the form, fit, and function of prototypes prior to tooling up for the injection molded production parts. For both plastic and metal, CNC machining provides fast turnaround and low cost for small quantities of parts. Learn all about ICOMold's CNC machining capabilities, which typically include tolerances to within +/- 0.2 to 0.3 mm for plastics and +/- 0.05 mm for metals. Parts that are CNC machined can also exhibit better structural integrity than those that are 3D printed, due to the nature of the manufacturing process. Secondary processes also available from ICOMold.
Learn more.


Reverse engineering software with never-before-seen features

3D Systems' Geomagic Design X 2020 combines robust 3D scan processing and complete CAD design functionality to enable faster, more accurate, and reliable reverse engineering. Using the software's newest features, engineers will benefit from streamlined modeling workflows as well as expanded modeling pathways for complex, revolved parts. The newest Geomagic Design X release includes an Unroll/Reroll function that enables an engineer to unroll the mesh to automatically extract a 2D sketch, make the modifications needed, and then re-roll the sketch for additional engineering. Wait, what? Wow. The software also includes a new Selective Surfacing feature that combines very fast organic surfacing with high-precision feature modeling methods.
Learn more.


Great Resources: One guide for all your retaining ring questions

Finding the best possible solution for your design challenge is no easy task. Smalley engineers have created a brand new Ask the Expert - Retaining Ring FAQ E-book that answers all of your retaining questions in one simple guide.
Get the guide today.


All about lead screws and how to apply them

Lead screws use the helix angle of the thread to convert rotary motion to linear motion. Learn all about their benefits, performance characteristics, design choices, life cycles, and more in this in-depth article from Thomson Industries.
Read the full article.


No Drip Spray Nozzles sanitize, clean, and cool

EXAIR's new 1/2 NPT No Drip External Mix Air Atomizing Spray Nozzles work in the same way the company's standard atomizing nozzles do, but have the added benefit of positively stopping liquid flow when compressed air is shut off. External Mix Air Atomizing Spray Nozzles have the highest flow rates and allow the air and liquid flow to be adjusted independently. They can be used on liquids above 300 centipoise. The patented No Drip design requires no additional air line to control the No Drip feature.
Learn more.


New from Ruland: Slit couplings

Reliance Precision Limited is now offering its slit couplings through Ruland's eCommerce platform and extensive worldwide distribution network. Slit couplings are zero-backlash and manufactured from a single piece of aluminum with intermittent slit cuts, allowing for high torque and torsional stiffness capabilities, low inertia, and long life. Reliance's design uses a proprietary slit pattern that has radiused as opposed to squared edges, reducing stresses that build up during misalignment conditions and torque loads. Equipment designers in industries such as packaging, scientific, semiconductor, solar, medical, and automation benefit from the wide range of sizes and performance characteristics offered by slit couplings.
Learn more.


Function-integrated machine frames from Rexroth include internal cable guide

Bosch Rexroth's new function-integrated profiles (FIPs) include a completely internal cable guide that allows for the safe and space-saving laying of cables, data lines, and hoses. Thanks to the new profile junctions, they can even be laid through profile connectors. The FIP range comprises four profile cross-sections with a host of accessories to build on the modular system. The entire solution can be combined with the established Rexroth modular profile system and provides an unprecedented level of design flexibility.
Learn more.


Intelligent chain monitoring avoids downtimes

Developed in-house by iwis, the non-contact chain elongation monitoring system (CCM-S) continuously measures the wear elongation of chains during operation and gives maintenance staff a timely warning that a chain needs to be replaced. If chains stretch and wear as a result of temperature and load, or if chains running in parallel have different lengths, even a deviation of one percent from the nominal chain pitch can lead to problems in a machine. With CCM-S, users can continuously monitor the elongation of chain drives using sensors without having to compromise production because of interruptions. Can be used with simplex, duplex, and triplex chains.
Learn more.


Hood latch comes in new ultra-slim design

SOUTHCO has refreshed its successful line of hood latches to accommodate the space limitations of next-generation servers, data centers, and similar applications. The new and improved HH Hood Latch features a thin profile, maintaining robust performance with a form factor of just 8 mm. The redesigned latch features an easy-to-use pop-up handle for intuitive operation. This unit offers a dual-engagement hole-mounting design, allowing for convenient installation with pin allocation at either location.
Learn more.


Robotic strain wave gearboxes

GAM has just announced the release of its new GSL series of strain wave gearboxes. The new gearboxes provide zero backlash and high torque in a small gearbox for robotic and motion control applications. This gearbox uses harmonic gearing for a very compact design that easily integrates into applications requiring high ratios and high precision in a small form factor. The GSL series is available in frame sizes 14 to 40 and reduction ratios 50:1 to 160:1.
Learn more.


How to choose commercially available O-ring cross-sections

There are 400+ standard O-ring sizes, so which is the right one for your application? What if multiple thicknesses are available for the same O-ring size? Dorothy Kern, applications engineering lead, Parker O-Ring & Engineered Seals Division, runs through the key considerations, including compression set, tolerances, contact width, and more. Very good info.
Read this informative Parker blog.


ServoClass Couplings have the advantage

Demanding applications require a coupling that holds up to shock loads caused by rapid acceleration and deceleration, start/stop conditions, and torque reversals in servo-driven systems. The ServoClass Coupling from Zero-Max has a longer-lifetime advantage because it is not as radially stiff as a bellows coupling, which reduces the reaction loads on the connected components and stresses within the coupling itself. Jaw/spider couplings do not perform as well as ServoClass Couplings either. The reason is that a coupling's spider element can deteriorate over time from heat and fatigue, shortening its lifetime. Also, jaw/spider couplings experience torsional windup in higher torque applications and have longer settling times when stopping higher inertial loads.
Learn more about Zero-Max ServoClass Couplings.


How to design the optimum hinge

Although many pin styles are available, Coiled Spring Pins are particularly well suited for use in both friction- and free-fit hinges. To achieve optimum long-term hinge performance, designers should observe some simple design guidelines. SPIROL provides these helpful recommendations.
Read the full article.


High-torque synchronous drive/timing belts

Automation-Direct SureMotion 5M and 8M (5-mm and 8-mm pitch) high-torque synchronous drive/timing belts are an excellent choice for many industrial applications. They have a curvilinear HTD (High Torque Drive) tooth profile that allows the belts to have a much larger pulley contact area for improved performance. The chloroprene belt body is heat and ozone resistant and features a high tooth-shear resistance. Widths from 9 mm to 30 mm and circumferences from 180 mm to 4,400 mm are available. Pitch sizes and widths match SureMotion pulleys to cover a wide range of power transmission requirements.
Learn more.


Air Force Research Lab improving processes for fabricating aircraft engine inlet ducts

The Kratos XQ-58 Valkyrie is an experimental stealthy unmanned combat aerial vehicle designed and built by Kratos Defense & Security Solutions for the United States Air Force Low Cost Attritable Strike Demonstrator program, under the USAF Research Laboratory's Low Cost Attritable Aircraft Technology project portfolio. [Photo: AFRL]

 

 

 

 

By Donna Lindner, Air Force Research Laboratory, Wright-Patterson Air Force Base, Ohio

Aircraft engine inlet ducts provide the engine compressor with a constant supply of air to prevent the compressor from stalling. Since the inlet is directly exposed to the impacting airflow, it must create as little drag as possible. The smallest gap in airflow supply can cause major engine problems as well as significant efficiency losses.

Part of the Air Force 2030 Science and Technology strategy includes the deployment of low-cost Unmanned Aerial Systems in mass to assist in future near-peer engagements. In order to realize this vision, new manufacturing strategies need to be identified that can support the rapid manufacturing of high-quality aerospace components at costs that are lower than what are currently available using legacy manufacturing processes.

If the inlet duct is to retain its function of providing sufficient air with minimum turbulence, it must be clean and flawless.

The Air Force Research Laboratory's Manufacturing and Industrial Technologies Division and the contractor team of Cornerstone Research Group, A&P Technology, and Spintech LLC conducted research to quantify the benefits of replacing legacy manufacturing processes with novel processes for the fabrication of an 11-ft-long, S-shaped engine inlet duct.

An 11-ft-long unmanned aircraft system inlet duct preform is shown prior to resin infusion. [Photo: AFRL]

 

 

The legacy fabrication process for the inlet duct consists of composite material preimpregnated with a synthetic resin, applied by hand, to a multi-piece steel mandrel. The mandrel is packaged and placed in an autoclave for processing. An autoclave is essentially a heated pressure vessel that supplies heat to activate resin curing and pressure to ensure there is minimal absorbency in the fully cured composite part.

The approach replaces the hand-applied composite prepreg with an automated overbraid process that applies dry fiber to a mandrel. The very heavy multi-piece steel mandrel was replaced with a light-weight, single-piece shape-memory polymer (SMP) mandrel, and the dry braided carbon fiber was processed with a low-cost epoxy resin using a vacuum-assisted resin transfer molding process.

One of the primary goals of this program is to understand part cost and production time benefits from introducing the new tooling and processing solutions.

The team completed element analysis finalization of the overbraid architecture, fabrication of a shape-memory polymer forming tool, and construction of the SMP mandrel that will serve as the tool during the preform overbraid process.

Because of inlet duct geometrical complexity, multiple iterations will be necessary to optimize the overbraid machine settings and thus minimize composite material wrinkling. A total of four inlet ducts will be fabricated, and legacy part cost and production time will be compared to the new design.

"We believe that the introduction of a reusable shape-memory polymer mandrel together with the automated overbraid process and an oven-based VARTM composite cure will lead to significant cost and cycle time reductions," said Craig Neslen, manufacturing lead for the Low Cost Attritable Aircraft Technology Initiative in the Manufacturing and Industrial Technologies Division. "Quantifying the manufacturing benefits and validating structural integrity will be critical to establishing a positive business case and convincing designers and manufacturers that the new materials and processes should be incorporated into future low-cost engine inlet duct designs."

The final inlet duct will be delivered to the government for further integration into the Aerospace System's Directorate's complementary airframe design and manufacturing program. Personnel at the Aerospace Vehicles Division will conduct static ground testing of the integrated braided fuselage and inlet duct structure.

"While we have yet to define all of the implications of attrition tolerance on design criteria and the resulting manufacturing materials and processes utilized, we do have a baseline with threshold requirements for strength and stiffness which we will assess via full-scale airframe ground tests," said Ray Fisher, aerospace engineer in the Aerospace Vehicles Division.

Published June 2020

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