Vertical-Axis Wind Turbines
The whole renewable energy craze has spawned lots of development with wind energy. Many windmills are popping up in the horizontal-axis orientation, much like the traditional Dutch windmills of old. The technology has been updated to gigantic and very expensive windmills at heights in the 300-500 foot range. This of course are very expensive, and have many hurdles to overcome on each installation.
Many inventors have worked to make smaller-scale windmills. Vertical-axis equipment seems to rule the day with this scale of equipment. The smaller vertical-axis wind turbines for home use are less expensive, less intrusive, and have fewer moving parts.
I found a great video from arturomoises64 of a demonstration of some vertical wind turbines in Santiago, Dominican Republic.
The author’s description is as follows:
These wind turbines are moved by low winds and even at high speed winds they will not go out of control. They are very high torque and very efficient. They measure 6 feet height by 11 feet wide and are made out of fiberglass and steel. This design is very safe for birds and do not need to be installed as high as other types of wind turbines. They are completely silent and are esthetically pleasing, a hypnotic blend of science and sculpture
The construction of the blades utilizes a composite material molded into a complex shape to catch the wind and turn the axis, which is undoubtedly connected to an electrical generator of some sort. Simple design, great application for composite materials!
Making a Small Mold
There are many methods and materials that can be used for making a fiberglass composite mold.
I found a video from Eastbay Composites that demonstrates a method for making small molds in a very quick an inexpensive fashion.
As you see from watching this, the basic construction materials are tooling gelcoat and inexpensive bondo for the support structure.
This mold construction technique certainly has drawbacks, but also has several advantages. None of the materials required spray equipment, which is messy. Brushes are inexpensive and easily disposed. A disadvantage of this method is that surface finish might suffer from a lack of consistency on the coating thicknesses for the gelcoat and the release agents.
Using bondo as the support structure is quick and easy compared to glass and resin, but can cause problems as well. It is more likely to crack, and can warpage issues as it cures and may be hotter in some areas than others. Bondo may have some difficulty maintaining dimensional tolerance as it shrinks during cure. Industrial resins used to create molds have minimal shrinkage in their chemistry and are placed on slower to minimize heat from the chemical reaction.
For quick, inexpensive and easy parts, this method from Eastbay Composites may work well for you. What has not been discussed yet is that the mold model can be the most difficult part. Off the shelf items are easy, but custom ones may be difficult. Creating a shape or surface is time consuming and tenuous. After that is complete, you can make your mold and final production parts!
Fiberglass Pool Installation
Fiberglass swimming pools have several advantages as compared to other types, such as concrete in-ground pools, vinyl-lined pools, and above-ground pools.
-They can be built off-site in a controlled environment.
-They are lightweight for transport and lifting into place.
-They have a durable and usually have a one-piece design.
-The material allows for design freedoms that are more difficult with other materials.
The many advantages of fiberglass swimming pools in residential use are numerous. They do have disadvantages as well, just like other materials. The outdoor environment can be very tough on any fiberglass structure. Proper cleaning and maintenance is very important to keep an appropriate appearance together.
Fiberglass pools can be easily delivered on-site with medium-duty shipping equipment and lifted in place with a crane. I found a great Youtube video demonstrating a lift over a large two-story house. The pool easily goes into place, ready for surrounding landscaping.
Automotive Application: Pickup Box
Fiberglass Composites have been used for ages in the automotive industry. There are advantages to doing this, including corrosion resistance, impact resistance, and weight savings. Toyota pickup trucks from the late 1980′s were made with steel sheetmetal beds that are very rust-prone in winter climates, especially those with salted roads. The response was to use a material that did not rust–fiberglass!
Toyota Pickup Box
This Toyota pickup box has fiberglass sides to eliminate the corrosion problem. The floor and front bulkhead are steel, as well as the missing tailgate. Using composite surely eliminated the rust problems associated with these vehicles, especially since it was used in the most apparent cosmetic areas that are most visible.
This pickup bed is not on a truck, because the frames of these trucks were also extremely rust-prone as well.
Composite electrical box
One of the composites applications that I found in a junkyard was a composite electrical box. It was discarded from a former use as an enclosure for electrical equipment in an industrial factory. Other than some minor discoloration and all of the holes from conduit, it is as good as the day it was new.
The advantages of using composites in this application include non-conductivity, protection from impact, and the ability to resist corrosion in tough environments. This is why it has outlived it’s factory setting.
Composites enclosure
An item like this where it has a good surface finish on both sides is going to be made in a set of matched-mold dies in a high-pressure and high-temperature press. It is likely to be manufactured with the Sheet Molding Compound (SMC) process, though Bulk Molding Compound (BMC) could also be at work.
Electrical panel enclosure
You can see on the front door all of the holes from its former installation. Holes on the side were used as well. It was customized for its application with all of the holes, and a new unit would arrive “blank,” without holes, as most applications are customized. The composite can be cut and drilled with metal working tools such as drill bits, holesaws, and saw blades.
SMC Truck Fender
SMC (Sheet Molding Compound) works well for heavy duty truck parts, especially ones requiring complexity, strength, and impact resistance. One of the projects I am working on is a heavy truck with these SMC parts, including a hood and a driver’s and passenger’s truck fender extensions. Each of these SMC parts is very complex in geometry because of its complex application. The following is a picture of one of the SMC fender extensions.
SMC Truck Fender Extension
This SMC part is all one single molded piece, having very complicated geometry. It can also be noted that there are not any undercuts, i.e. the mold can open and close without having to move around the part. It has a mostly constant cross section, is not supported by any metal struts, and is attached to the cab by three bolts. The geometry and details to match the cab and hood styling are molded-in so that the part can be painted and bolted on the truck.
If a part needing this much complexity was manufactured with sheetmetal, it would have many more pieces of the assembly and much more bracing. Metal would also not have the resistance to corrosion and impact that is enjoyed by this composite part.
This fender extension is from a truck that has been on the road since 1993, with over 270,000 miles on it. This part has been in the wild for over 15 years, and has been exposed to tons of road salt, debris from the tires, and lots of other environmental exposures. It has survived well, only needing an update in paint to refresh its look.
Another great application of composites!
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