Thursday, August 23, 2012

This last image shows the fin sanded down significantly.

This last image shows the fin sanded down significantly.  These are extremely thick fins, nearly half and inch at the base.  I have little doubt that they are strong enough, but how about adhesion to the rocket?  The OP suggests he may just do a surface mount with epoxy!  That worries me, no matter how thick that root edge.  However, he makes a valid point - tip to tip lamination will only interfere with the precision built into these fins, and has not always worked in the past on mach 3+ rockets.

"As I mentioned in a few other threads, I am currently building a 98mm MD rocket for BALLS, so I decided I'd make a build thread. I'm not going to post my full design yet, since it's still somewhat fluid as I'm building - especially with regards to the recovery system. However, I will post some pictures as I go. This design is expected to weigh in at less than 10 pounds with everything but motor (I'm actually shooting for 7, China Composite Resin - Structural Adhesive for Carbon/ Glass Fiber Fabrics Manufacturersbut I'm not convinced that will happen), has an overall length of 76.6 inches from the tip of the nose to the back of the nozzle. Unlike several of the N5800 designs proposed and under construction, I'm going for a metal-free build, in the hopes that I can make this work with all composite structures (just for a bit of added challenge). Depending on the sim you believe, as well as a few parameters that aren't quite nailed down yet, it's expected to go anywhere from 90,000 to upwards of 130,000 feet if it boosts straight and holds together, with a top speed of mach 4.2, so it should soundly take the N record if it actually holds together, as well as having a shot at the Carmack prize if it is still unclaimed as of BALLS this year.

First off, the fins. These are relatively simple shapes,China Prepreg 75g/㎡, T700 12K, Unidirectional Manufacturers not swept terribly far back (sweeping back beyond the mach angle is impractical at this speed, so I'm instead going for a mild sweep with a razor sharp leading edge). I started with 0.44 inch thick high grade CF stock, which was custom made for me (and cut to the basic fin outline) by ACP composites. It was made in an autoclave using prepreg, and it was cured at 350F, with an anticipated Tg of around 400F, so it should be substantially more heat resistant than ordinary CF plate would be. It is also incredibly strong, incredibly heavy, and incredibly high drag, due to the 0.44 inch thickness."

At a conservative 10 lbs for the airframe without motor, or 7 with some luck, this rocket will be a great test of the proposed N5800 to N5800 space shot, where the upper stage needs to be around 7 or 8 lbs to have a good shot at making 100 km.  China Composite Resin - Structural Epoxy Paste Adhesive ManufacturersGranted this time, it will take on far more heat and stress than any upper stage would see.  While the upper stage would hit mach 5+ in a two stage configuration, it would do so at 30, 40, or 50,000 feet where things are nice and chilly and the air is thin.

Thursday, August 16, 2012

Brief tips to extend bearing life

    The mobile bearing use in harsh environments, the bearing ring and the sealing cover is essential, because they prevent dirt intrusion, extending bearing life. Roll in the mill usually consists of four sealed tapered roller bearings support. Required to withstand a strong impact load, water and debris intrusion.angular bearing
    Japan, NSK has developed ultra-easy to seal a clean roll neck bearings. These bearings under severe lubrication conditions, the load capacity increased by 34%, and high reliability, long life, easy to maintain. This performance improvement is to optimize the mechanical design, using the results of new materials and patented sealing technology. Compared with the traditional roll neck bearings, the seal roll neck bearings not only basic dynamic load rating improved 34 percent, and life expectancy by 2.7 times.

    The second factor is the performance of ultra-capacity sealed clean roll neck bearings NSK has developed the Super-TF bearing steel. This material to solve the bearing life under contaminated or insufficient lubrication conditions. Experience has shown that, in the pollution of operating conditions, bearings vulnerable to debris intrusion and pollution. NSK s research shows that the pollution or marginal lubrication conditions, the bearing life can improve through the improvement of bearing steel microstructure. The new seal structure of the main seal and the hole sealed.

    The negative pressure generated in the bearing can be caused by water intrusion from the main sealing hole sealing structure has a great influence on the negative pressure. Therefore, to reduce the negative pressure in the bearing is to prevent water from entering the basic requirements. The most effective way is to make the hole to seal does not directly in contact with water, while retaining hole sealed original function – to prevent the intrusion of water and dirt from the side of the roll neck. Sealing method using surface contact instead of line contact, whether it is running the process, or static process, the surface of contact hole sealed-tight and good. Therefore, the new super-capacity sealed clean roll neck bearings with higher reliability than traditional sealed roll neck bearings.

    In addition, SKF Italy seal recently developed a new generation of oil and grease seals MudBlock. Optimize the design of the seal structure can effectively prevent the intrusion of dirt. Sealing structure for a radial sealing lip, outer diameter and seat between a clamping spring and fixed ring. The new structure there is a push baffle between the bushings and seals, and seals the outer surface of the bushing inner diameter rubber inner lip with a waterproof grease pre-lubrication. According to operating conditions and application requirements, MudBlock available a variety of flexible material. These materials include: nitrile, polyacrylic acid resin, fluorinated synthetic rubber.

Tuesday, August 14, 2012

Designing and Preparing the Car for Wrapping

Understanding the shape and size of the car and all its nuances is a crucial element in the design procedure; as a result, taking measurements just before you do any design perform can be a must. You really have to have an excellent handle on templates, templates are so key because positioning is crucial. In the event you must do a lot of reprints, then that could break your company. Authorities also suggest an auto library that contains vector pictures of vehicles, trucks and buses plus a digital camera with which to take photographs. The aim will be to know each and every inch from the car. If you don’t take time to complete this up front, then you can finish up with text more than a door manage. Although you are wrapping a 2003 Dodge Caravan, for instance, measurements are still critical since you’ll find slight differences that could cause main difficulties for the duration of installation. You can get this library in the finish of this short article.

Designing for wraps is totally diverse than other kinds of design operate, It’s like any new media, you need to find out the media and you need to learn what’s going to capture the consideration in the people. It’s far more than just putting graphics on an auto. Steer clear of using too a lot text or colours. Several individuals are utilizing rainbows on cars and that causes the intended viewer to miss the message. Actually, generating a bold statement is amongst the biggest challenges in designing for wraps. You have to hold it simple. You’ll need a robust message. You only have a handful of seconds to get the message across as the car passes by, It’s a branding media; it’s not a message media. You just show the brand for recognition more than to run a brochure.

Among the most significant errors with wrap styles is going overboard with flashy graphics or wanting to put an one-dimensional design on a three-dimensional vehicle. Commonly where your hood as well as your front bumper transition towards the side from the auto is difficult. You’re generally laying down a flat design on the hood along with a flat design on the side with the vehicles and should you possess a wacky design, then they don’t transition nicely on either side in the hood and on either side of the trunk on the back. 1 key to good results boils down to widespread sense: function closely together with the client throughout the style procedure. In fact, you can even outsource the design function, the printing and also the installation and essentially act as a sales rep. When the buyer wants to cope with you and also the price tag is fine, then go for it.

After the style perform is complete, the next step is preparing the car for installation. Suitable cleaning and preparation in the substrate prior to application is critical to the success of the wrap, due to the fact if the vehicle just isn’t thoroughly cleaned immediately prior to application, then the result could be adhesion loss. You want to ensure to get all of the dirt out of any contours and grooves, any dirt can impact how any from the film adheres to the substrate. Most vinyl manufacturers recommend cleaning the vehicle having a commercial detergent and water. If grease, oil, wax or any other grime is present, then the substrate need to be scrubbed with a solvent and wiped with a soft, lint-free cloth ahead of it dries. Isophoryl alcohol is sturdy sufficient to clean away any left more than impurities that could hinder the adhesive, but not so sturdy that it’ll harm the paint. Nonetheless, authorities recommend testing the cleaning solvent on an inconspicuous region of the application surface first to check for possible damage.

Specialists say a frequent mistake through the preparation method is just not allowing the vehicle to dry completely. It may take as much as 24 hours to get an automobile to dry entirely, specially in humid or cold atmospheres. Emphasize on the significance of surface preparation, a single widespread mistake that is effortless to know but frequently overlooked is getting the car in the proper temperature for installation. Sign shops in the north are at somewhat of a disadvantage because vinyl films are generally much more susceptible to failure in cold environments. Even if the car seems like it’s dry, if it’s cold and there’s moisture within the air, then it sticks to the surface with the car and creates barriers for the overall performance in the film.

In the event you are applying film to a newly painted surface, Avery recommends following all drying and curing directions supplied by the paint manufacturer prior to surface preparation and film application. Avery also recommends the use of top quality exterior grade paints and OEM systems. You also should prepare the glass should you are going to apply perforated vinyl to these places. Like the vehicle itself, the glass should be perfectly clean. Avery recommends removing any stickers, paint or over-spray making use of a single razor blade scraper. Then spray the glass with cleaning resolution, squeegee it dry using a soft rubber window squeegee and wipe the edges utilizing lint-free paper towels.

Thursday, August 9, 2012

Advantages of Carbon Fibre Composites

Carbon fibre can be explained as very thin strong fibres and is generally used to reinforce composite materials, particularly the category of materials known as carbon fibre or graphite reinforced polymers. It's also known as the reinforced plastic or carbon fibre composites. As a compound it's admired for being more strong and lighter than fiberglass. It is of much importance to engineers due to its sturdiness. It's a kind of material that is lighter than aluminum and stronger than steel. It's amazing.

Although, it's an expensive compound, but has an amazing weight-to-strength ratio and is a structure of graphite in which the sheets are long and thin. Carbon fibre composites are generally made from a polymer, known as polyacrylonitrile, by a compound heating process. It is regularly used because it has frequent qualities that make it an ideal compound for the construction of objects and items required to be light in weight but extremely high on strengthness.

Carbon fibre composites are extensively used in manufacturing components of aircraft and automotive products. It is a compound typically used in aerospace and automotive fields, as well as in sailboats and modern bicyclers, where the material's strength-to-weight ratio is beneficial.

Some extra properties that make it perfect are its tremendously low flex fatigue over time, it's not flammable and it's stable in the environment.

Nowadays, carbon fibre composites mainly found in racing cars, although like all latest technologies it's rapidly finding its way into more and more vehicles. These carbon fibre composites can be manufactured in huge quantities so manufactures combine it into sheets, bars, tubes and other shapes.
It can be used in numerous layers for improved strength.

The major benefit of carbon fibre composites is that its weight is just one-fifth of steel and its potency is more than of steel. These composites are widely used in manufacturing components that require durable strength and low weight.

Monday, August 6, 2012

Wind Turbine Blades: Carbon Fiber vs Glass

From its inception, the wind energy industry has had to fight to compete with other forms of electric power generation. Wind energy producers not only face that battle, but also wage war against each other for a competitive share in the wind market. Both battles boil down to a need to improve the economics of wind energy through increased energy capture. This has prompted a well-documented growth spurt in the size of turbines and rotor blades for land-based and offshore systems (see “Wind turbine blades: Big and getting bigger,” under “Editor’s Picks,” at top right). Offshore turbines are moving quickly from 3 MW to next-generation turbines rated at 5 MW and larger, on which blade lengths for both on- and offshore systems regularly exceed 45m/148 ft. As blades grow longer, the idea of converting structural areas of the blade from E-glass to significantly stiffer and lighter carbon fiber begins to make sense, despite the latter’s greater upfront cost.

Carbon fiber already has proven to be an enabling technology for turbine manufacturers Vestas Wind Systems A/S (Aarhus, Denmark) and Gamesa Technology Corp. (Zamudio, Vizcaya, Spain). Both companies embraced carbon fiber years ago, using it in select structural parts of their blades and taking advantage of the lighter weight blades throughout the turbine system. Lighter blades require less robust turbine and tower components, so the cascading cost savings justify the additional cost of carbon. “Vestas and Gamesa designed their turbines around the use of carbon fiber and, by virtue of that, the whole system cost is less than a system with an all glass-fiber blade,” confirms Dr. Philip L. Schell, executive VP of wind energy at carbon fiber manufacturer Zoltek Corp. (St. Louis, Mo.).

And that is before the increase in turbine efficiency that additional length enables. For example, the switch to carbon fiber enabled Vestas, initially, to add 5m/16 ft in blade length without any additional weight gain. The Vestas V112-3MW turbine is designed for low- and medium-wind areas and sports three 54.6m/179-ft blades. These blades have the same width as the company’s 44m/144-ft blades, but they sweep an area that is 55 percent larger. The result is considerably higher energy output.

More recently, GE Energy (Greenville, S.C.) joined the fray, specifying carbon fiber in its next-generation wind blades, including the 48.7m/160-ft blades for its 1.6-100 turbine. Yet, speaking at CompositeWorld’s 2011 Carbon Fiber conference in Washington D.C., Nirav Patel, senior lead engineer of GE Energy-Manufacturing Technology, issued a warning that carbon fiber cost and supply concerns could be showstoppers to further use of carbon fiber in GE applications. Patel also called for increased automation and improvements in manufacturing processes (see “What is carbon fiber’s place in wind energy systems?” under “Editor’s Picks”).

Notably, it may be GE’s use of carbon fiber to increase blade length on its 1.6-MW system that will ultimately push more wind energy companies to embrace carbon fiber. “GE’s decision to put a 100m [328-ft] diameter rotor on a 1.6-MW turbine has captured the attention of a lot of companies in the industry,” says Dr. Kyle Wetzel, president, Wetzel Engineering (Lawrence, Kan.), which designs wind turbines and rotors. “As a result, we are being approached by a number of companies that want to similarly upsize their machines.”
A carbon backbone

Retrofitting existing turbine designs with longer blades that incorporate carbon has become a shortcut to marketability. “It’s always best to do a system-level design — treating the rotor, the turbine, and the tower as one system — but the reality is that the energy market is so competitive and everyone is so worried about what their competitors are doing, that they often don’t have time to do a system-level design,” explains Wetzel. “So, if a company decides to go to an extremely large blade on an existing system, then carbon fiber becomes an enabling technology by allowing for increased blade length without increased weight.”

Currently, carbon fiber is used primarily in the spar, or structural element, of wind blades longer than 45m/148 ft, both for land-based and offshore systems. The higher stiffness and lower density of CF allows a thinner blade profile while producing stiffer, lighter blades. The rough rule of thumb for weight reduction, offers Schell, is at least 20 percent weight savings when moving from an all-glass blade to one with a carbon fiber-reinforced spar cap. Offshore wind systems — where the smallest turbines are rated at 3 MW — will especially benefit from the characteristics of carbon.

“Assuming that offshore continues in its positive direction and costs remain under control, I wouldn’t be surprised to see 8-MW to 10-MW turbines with 80m to 100m [263-ft to 328-ft] long blades in the next three to five years,” says Schell.

“A 100m blade made entirely out of glass fiber could weigh up to 50 metric tonnes [110,231 lb],” he notes. “When you consider achieving a 20 to 30 percent weight savings by incorporating carbon fiber, that’s a weight savings of 15 metric tonnes [33,069 lb]. Multiply that by three and it can make a significant difference,” Schell stresses.

“In a 100m blade, the weights get so high that we are starting to investigate using carbon in the skins of the blade for added weight reduction,” says Wetzel. In a conventional, land-based blade design, however, the spar cap is the only area where Wetzel would recommend CF, but Schell notes that one company is using a hybrid glass/carbon reinforcement in the root section of the blade.

“In some very specialized blades, we’ve incorporated carbon in the trailing edge in an effort to tune some of the natural frequencies of the blade,” says Wetzel. “And carbon could come into play in aeroelastic tailoring,” he adds, noting that the idea is to build a small amount of twistability into the load response of a blade with asymmetric fiber layup in the blade skin to shape the power curve and reduce loads. “It’s a concept that’s been around for about 10 years, but I think it’s going to soon find its way into some commercial wind blades — very large blades.”

Wednesday, August 1, 2012

Structure of heat-resistant film on cars

First, they added a layer resistant to ultraviolet (UV) in the colored class. Two-layer sheet has overcome the effects of fading due to sunlight, heat removal capability is also improved, though still a few points of error concern loosen adhesive film, air bubbles, ripples waves.

 Hybrid films including layers: metallic coating, colored layer After that, manufacturers continued to add layers of metal thin film dye before and after UV resistant layer. Capable of removing excess heat by the principles reflected light by 40%, reducing the error on the second film layer, extending the life of the film, but the downside appears likely reduce light transmission.

 A revolutionary efforts in the movie against heat. Manufacturers are trying to do the film becomes transparent. To do this, they need to know we feel the so-called "heat" from the three main signal sources: 38% of visible radiation (light), 5% of ultraviolet radiation (UV), 56 % infrared radiation (IR) Movies colored light most resistance, then the ultraviolet, the metal layer "lock" the infrared part. Manufacturers need to realize that "lock" completely and let infrared light passes through more.

 They start by examining the layers made of ceramic and carbon materials and have found the desired genre: film spectral selectivity. These plates are designed to "lock" 70% - 90% of infrared radiation, while only 10% of course - 30% light. They are transparent plate, blocking from 40% to 65% heat will pass through the glass.

 There is a difference between heat-resistant film used on car and on the glass door. Heat-resistant film is designed to be safe for cars but not good for the window film used by the automobile to absorb more heat is reflected heat. Movies for the opposite window, reflecting more heat absorption. Another reason is because movies require high light transmission to drive the observer.