As a freelancing draughtsperson, I have received widespread experience for my contributions in both mechanical and electrical draughting while being involved in product development, presentation, and design reviews. My work involved a combination of technical expertise and creativity. I also brings together technologies from different environments and works inventively. In so doing, I am able to translate ideas into working products that meet the needs. I also endeavour to help engineering designers in improving their productivity. My primary function was to identify the specific needs of professionals designers within the construction industry and then to meet these requirements in a professional, time sensitive and cost-effective manner. I also offer services as complex as Concept Design, Project Planning and Compiling Design Applications or Presentations. I work with a team of skilled and experienced draughtsman from different disciplines who are dedicated to providing reliable and professional service that is on time every time. We use the latest Synchronous 3D modelling software and also use laser as well as infrared reflector-less surveying equipment onsite when producing layout drawings, assembly or detail drawings and mechanical surveying depending on the clients requirements.

Wednesday, September 28, 2016

Workhop Layout | Design

Once the workshop location is determined, it's time to begin planning how to lay it out. First, acknowledge the need to formulate a plan that's realistic in terms of the space allotted. The size of the structure or workspace will place some constraints on how much can be done. Taking into account size limitations, begin fashioning a plan that keeps efficiency in mind.

The layout of a workshop will be based, in part, on how it will be used — whether for carpentry, fine woodworking, metalwork or other activities. Regardless of category, however, it's important to keep in mind the principles of efficiency and organization. A layout that's clearly thought out in terms of functionality will make all the difference in creating a workspace that offers a pleasant surrounding as well as a space that's conducive to work.
Rather than purchasing equipment first and then trying to decide where to put it all, start with a diagram instead. For the workshop in our project, the diagram included major stationary tools and storage placed along the walls, and a sizeable workbench placed in the center of the room. 


The problems related to plant layout are generally observed because of the various developments that occur. These developments generally include adoption of the new standards of safety, changes in the design of the product, decision to set up a new plant, introducing a new product, withdrawing the various obsolete facilities etc.

Objectives of a good plant layout are –
1. Providing comfort to the workers and catering to worker’s taste and liking.
2. Giving good and improved working conditions.
3. Minimizing delays in production and making efficient use of the space that is available.
4. Having better control over the production cycle by having greater flexibility for changes in the design of the product.

Principles of a good plant layout are –
1. A good plant layout is the one which is able to integrate its workmen, materials, machines in the best possible way.
2. A good plant layout is the one which sees very little or minimum possible movement of the materials during the operations.
3. A good layout is the one that is able to make effective and proper use of the space that is available for use.
4. A good layout is the one which involves unidirectional flow of the materials during operations without involving any back tracking.
5. A good plant layout is the one which ensures proper security with maximum flexibility.
6. Maximum visibility, minimum handling and maximum accessibility, all form other important features of a good plant layout.

Types of layouts –
1. Process layout – These layouts are also called the functional layouts and are very suitable in the conditions, when the products being prepared are non – standard or involve wide variations in times of processing of the individual operations.
Such layouts are able to make better utilization of the equipment that is available, with greater flexibility in allocation of work to the equipment and also to the workers. Imbalance caused in one section is not allowed to affect the working of the other sections.
2. Product layout – These layouts are also known as the line layouts or the layout by sequence. In such layouts, the manufacturing cycle is small with minimum material handling. The space required is small and quality control is easy to exercise.
3. Project layout – Such layouts are also referred to as the fixed position layouts. In these layouts, the components, heavy materials, sub assemblies – all remain fixed at one place and the job is completed by movement of machines, men and tools to the location of the operations.

For most workshop applications, efficient workspace design follows a triangle, with the most important workstations at the three corners of the triangle.

A shop geared toward woodworking would have lumber storage located at one corner of the triangle. Storage space for wood — both long pieces and flat plywood pieces — should be adequate. Raised storage, such as racks or shelves mounted on the wall, must be sturdy. Wood storage should also be in close proximity to the stationary tools or machines (table saw, jointer, power planer, etc.) to avoid frequently carrying heavy wood across the span of the workspace. Wood storage should be handy and near the area where the heavy woodworking tasks will take place. Keep in mind that a considerable amount of space will be needed around stationary tools such as a table saws and jointers for manipulating large pieces of raw lumber.

The second corner of the triangle is in the center of the room and, in our case, is where the workbench is located. Following work progress in sequence, the workbench is typically the second workstation where medium-duty work is done after heavier preparatory or wood-milling steps are finished. The workbench is where work is typically done using hand tools or smaller power tools such as hand drills, routers and joinery tools.

The third corner of the triangle is the finishing station, where fine and detailed work takes place. At this station, tasks such as sanding, wood finishing and painting may take place. Since the detailed work is likely to be done here, it may be critical to keep this station more organized, clean and free of dust than the others.
Segregating the functional workstations in this way helps to keep the right tools and materials where they are needed for specific tasks. Meanwhile, keeping the three workstations in the close proximity of the triangle configuration makes it easy to proceed from one phase of a project to the next in a logical fashion.
Adequate storage for tools is essential, but easy access is also highly important for an efficiently designed workshop.

General tool storage can be in an area adjacent to the triangle so that individual tools are in easy reach for any project. Efficient design helps eliminate wasted time searching for necessary tools, and wasted steps carrying items back and forth — both of which can add up quickly.

Mamphake Mabule
Technical Writer | Dihlakanyane Books

c. 2016, Mabule Business Holdings

Monday, September 19, 2016

Power Plant | Engineering

When looking for opportunities to improve the performance metrics of a plant, pumps and fluid handling systems should be primary targets for evaluation, optimization and maintenance due to the sheer number and the influence on overall performance. Both centrifugal and positive displacement pumps are utilized in power generation applications. Of the two, engineers are generally more familiar with centrifugal pumps, which use an impeller to move fluid through the application process. The velocity of the rotating impeller imparts energy on the liquid and causes a rise in pressure (or head) that is proportional to the fluid's velocity. Positive displacement pumps – and, in particular, rotary variants – are less common, but can prove to be more cost effective and offer more efficient fluid handling in many applications. Instead of creating pressure, positive displacement pumps simply move liquid. Pressure is generated due to resistance to movement of the liquid downstream of the pump.

Things to Consider:
Whether you are an original equipment manufacturer (OEM), an engineering, procurement and construction (EPC) firm designing a new system, or a power plant operator looking to improve the performance and reliability of an existing system, here are 5.5 things to consider regarding pumps and pumping systems.

1. Liquid
The type and nature of the liquid being handled is a primary consideration when determining which pump technology to use. When handling viscous liquids such as heavy crude oil, bunker or residual fuel oils, low sulfur fuels and distillate fuels, multiple screw pumps – a variant of positive displacement pumps – provide remarkably good operating efficiencies as opposed to centrifugal pumps. The high efficiency performance of multiple screw pumps provides a clear advantage over centrifugal pumps where liquid viscosity exceeds 100 SSU (20 centistokes). Progressing cavity pumps are an excellent choice for wastewater and fuel sludge, as they can handle fluids that are contaminated or contain abrasive materials.

2. Supply
The specific hydraulic characteristics of positive displacement and centrifugal pumps lead to clear recommendations to keep total cost of ownership (TCO) as low as possible. When the system pressure is subject to change, a positive displacement pump is recommended, as it will remain efficient even when operating at varying pressures. While centrifugal pumps provide good efficiency within a relatively limited range of heads (pressures), this efficiency deteriorates rapidly if the head is too low. It suffers even more when the head exceeds the ideal range. Positive displacement pumps are the most economical choice when liquid viscosity changes, but flow volume remains constant. The efficiency of centrifugal pumps drops rapidly when viscosity is outside the optimal range (also known as the Best Efficiency Point, or BEP), whereas positive displacement pumps are less susceptible to these fluctuations.

3. Discharge
Whether pressure is constant or not is another key factor in the determination of which pump technology is better suited to the application. When the system has varying pressure requirements, centrifugal pumps will be forced to operate outside of their Best Efficiency Point, increasing the stress and wear on the pump. In these conditions, positive displacement pumps are the better choice to ensure high reliability. Today's high performance three screw pumps can operate with system pressures up to 4500 psi (310 bar) and flows to 3300 gpm (750 m3/h) with long term reliability and excellent efficiency. Power levels to 1,000 hp (745 kW) and higher are available.

4. Operations
When specifying pumps, consideration should be given to the mode of operation as well as to the operating conditions; will either change significantly? If flow volume remains constant, but pressure or delivery head varies, positive displacement pumps are the right choice due to their fixed displacement design. In contrast, centrifugal pumps are particularly efficient when operating on water-thin liquids at fixed operating conditions where it is possible to select the pump based on exact requirements. Centrifugal pumps will incur noticeably higher costs for spare parts, maintenance and downtime if viscosity and pressure are not constant. In either case, costs can be significantly reduced by operating a pump close to its most efficient range.

5. Sizing & Selection
Selecting the right type of pump – centrifugal or positive displacement – is important, but it is also critical to ensure that the pump and fluid handling system is properly sized. Figure 4 is a performance curve typical of multiple screw pumps. It shows excellent efficiency over a broad range of discharge pressures. When properly sized, multiple screw pumps also can handle various grades of liquid fuels, such as distillate or residual oil, using the same pumps and driver. This can provide a utility with some diversification of available oil supplies. For example, combustion gas turbines can be started and stopped using light distillate fuel while running on less costly (and higher heat value) heavy fuels.

If each piece of equipment is over-engineered, the power plant will have a system that is too large, performs at less than optimum efficiency, consumes excessive energy and adds higher maintenance and service costs. Conversely, a pump that is undersized may cost less at the outset, but the cost to rework or replace the system to meet performance expectations will outweigh the initial savings. The best rule of thumb is to size for worst-case flow and power requirements. In order to ensure the system is delivering adequate flow – especially in applications where fuel is being delivered to a turbine – size the pump for the highest temperature and lowest viscosity conditions. In contrast, during startup (cold) conditions, the fluid will have a higher viscosity, resulting in a higher power requirement. In this case, motor sizing is also important, making sure it can deliver the required power. Screw pumps offer excellent suction lift capability, which provides an operation margin for "upset" conditions, such as during startup when the liquid may be cold and more viscous or when there is an extended distance to the supply reservoir. This operation margin allows the use of smaller supply piping, reducing component costs and a simpler design. Centrifugal pumps offer good potential for optimization efforts simply because there are more of them. Centrifugal pumps should be selected for, and normally operated at, the manufacturer's design rated conditions of head and flow. This is usually at the best efficiency point, which is where pump impeller vane angles and the size and shape of the internal liquid flow passages provide the optimum combination of pressure and flow. As you move away from a centrifugal pump's BEP, the shaft will deflect and the pump will experience vibration. This causes reduced performance and accelerated wear.


Power plant operators tasked with improving efficiency and reliability should initiate a scheduled preventive maintenance program as part of the operational plan. Pumps used in auxiliary systems for lubrication will, by nature of their clean working conditions and application, require less preventive maintenance than pumps used for primary applications such as fuel injection and fuel forwarding. In both positive displacement and centrifugal pumps, the following components should be inspected, serviced and replaced when necessary to ensure optimum efficiency and reliability:
• Radial Bearings: if not sealed, these will need periodic lubrication and may need to be replaced if vibration or excessive heat is being generated
• Mechanical Seals: check for leakage and replace if necessary; it should be noted that a mechanical shaft seal is not a zero leak device
• O-rings and Gaskets: check for deterioration and replace if necessary

As a service to their end users, many pump manufacturers provide these parts in what is sometimes called a "minor kit," allowing the customer to easily identify and order the parts they need for a scheduled maintenance program on the pump. In addition to the items mentioned above, centrifugal pumps also require inspection of the impeller, which can be replaced if worn or damaged. For positive displacement pumps, virtually every wearing part of the pump – screws, gears (in the case of two-screw pumps), and housing – can often be replaced in the form of what some manufacturers refer to as a "major kit." When repairing a pump with a major kit, the user essentially has a new pump, at a cost that is somewhat lower than replacing the entire pump. When servicing pumps and fluid handling systems, it is recommended to only use replacement parts manufactured or certified by the pump manufacturer. Knock-offs, or "pirated parts," may work initially, but are typically not manufactured to the same standards as OEM parts and could result in early failure, leading to system downtime, damage to other components or even injury. In most cases, use of non-OEM parts will void any original equipment warranties. Using parts approved by the manufacturer will result in a longer service life, extended intervals between maintenance, a more predictable process and an increased system efficiency – not to mention peace of mind.

Pumps and fluid handling systems should be primary targets for evaluation, optimization and maintenance.
Centrifugal pumps offer good potential for optimization efforts, simply because there are more of them. Pumps used in auxiliary systems for lubrication will require less preventive maintenance.

Monday, September 12, 2016

Electromechanical Modeling | Engineering

The purpose of Electro-Mechanical Modeling is to model and simulate an electro-mechanical system, such that it's physical parameters can be examined before the actual system is built. Parameter estimation and physical realization of the overall system is the major design objective of Electro-Mechanical modeling. Theory driven mathematical model can be used or applied to other system to judge the performance of the joint system as a whole.

In engineering, electromechanics combines electrical and mechanical processes and procedures drawn from electrical engineering and mechanical engineering. Electrical engineering in this context also encompasses electronics engineering. Devices which carry out electrical operations by using moving parts are known as electromechanical. Strictly speaking, a manually operated switch is an electromechanical component, but the term is usually understood to refer to devices which involve an electrical signal to create mechanical movement, or mechanical movement to create an electric signal. Often involving electromagnetic principles such as in relays, which allow a voltage or current to control other, usually isolated circuit voltage or current by mechanically switching sets of contacts, and solenoids, by which a voltage can actuate a moving linkage as in solenoid valves. Piezoelectric devices are electromechanical, but do not use electromagnetic principles. Piezoelectric devices can create sound or vibration from an electrical signal or create an electrical signal from sound or mechanical vibration. Before the development of modern electronics, electromechanical devices were widely used in complicated systems subsystems, including electric typewriters, teleprinters, very early television systems, and the very early electromechanical digital computers.

Beginning in the last third of the century, much equipment which for most of the 20th century would have used electromechanical devices for control, has come to use less expensive and more reliable integrated microcontroller circuits containing ultimately a few million transistors, and a program to carry out the same task through logic, with electromechanical components only where moving parts, such as mechanical electric actuators, are a requirement. Such chips have replaced most electromechanical devices, because any point in a system which must rely on mechanical movement for proper operation will have mechanical wear and eventually fail. Properly designed electronic circuits without moving parts will continue to operate properly almost indefinitely and are used in most simple feedback control systems, and appear in huge numbers in everything from traffic lights to washing machines.

The modeling of purely mechanical systems is mainly based on the Lagrangian - a mathematical function called the Lagrangian is a function of the generalized coordinates, their time derivatives, and time, and contains the information about the dynamics of the system. No new physics is introduced in Lagrangian mechanics compared to Newtonian mechanics which is a function of the generalized coordinates and the associated velocities. If all forces are derivable from a potential, then the time behavior of the dynamical systems is completely determined. For simple mechanical systems, the Lagrangian is defined as the difference of the kinetic energy and the potential energy. There exists a similar approach for electrical system. By means of the electrical co-energy and well defined power quantities, the equations of motions are uniquely defined. The currents of the inductors and the voltage drops across the capacitors play the role of the generalized coordinates. All constraints, for instance caused by the Kirchhoff laws, are eliminated from the considerations. After that, a suitable transfer function is to be derived from the system parameters which eventually governs the behavior of the system. In consequence, we have quantities (kinetic and potential energy, generalized forces) which determine the mechanical part and quantities (co-energy, powers) for the description of the electrical part. This offers a combination of the mechanical and electrical parts by means of an energy approach. As a result, an extended Lagrangian format is produced.

Mamphake Mabule
Draughtsman | Mamphake Designs

Monday, September 5, 2016

Product Development | Engineering

similar to the one listed below. This is a general outline of getting a product idea from concept to market. It is a time tested formula and used in many companies across many industries. There are several variants of this formula, all of them are good as they fit different situations and types of product development. The most critical time in designing a mechanical system for cost saving and improving product performance comes at the very beginning of the design process. Without a good, well thought through base design, the rest of project quickly becomes costly and can result in huge issues that result in poor product performance. Mechanical engineers that can catch problems in the early design, or have the experience to never create the problems in the first place, save many of the headaches and cost overruns that happen later in production. Below is the process broken into the phases I normally use.

Concept Phase
This is the initial phase where the idea for the new product is generated and documented. The idea here is to flush out the idea as much as possible and assess if it is worth pursuing. To some degree, this is always done by an inventor or entrepreneur before coming to me, for why else would someone hire a product design and development professional unless they already have an idea they want to pursue.

Discovery Phase
This is an added phase in my process where a customer shares their idea with me so I can bid on it. It's common practice to sign a non-disclosure agreement up front with the customer to keep what is discussed confidential (keeping a customer's information confidential is something I do even without the agreement in place, unless agreed to by the customer). I also work with the customer to flush out the idea, this usually stems naturally from my need to have a good specification to create a quote and this process can range from a short phone call for a simple design to a couple of weeks of talks if the design is complicated or requires a lot of detail. I do not charge for this service thou..... At the end of this phase I usually deliver a proposal to the customer with a firm quote for the preliminary phase and estimates for the other phases beyond that.

Preliminary Design Phase
In this phase, I create a preliminary design based on the specifications agreed upon in the discovery phase. I also create an engineering model and do any other engineering and design that is necessary to flush out the product so that there is a high level of confidence that the design will work before proceeding to detailing the parts and creating engineering drawings and documents.

This phase is really where the bulk of the product design & development is done. At the end of this phase the work is summarized and delivered to the customer at a Preliminary Design Review (PDR). A written technical report is also delivered detailing the work done in this phase. After this phase, it should be very clear to all parties what the final product will look like and what its features will be. If, after the review, the customer believes parts of the design need to be tweaked or they decide they want modification or new features added this will be incorporated into the next phase. Mechanical Engineering Professionals, will then update the original proposal and give a firm quote to our customers for the next phase before proceeding.

Critical Design Phase
Most of this phase is for detailing the design and creating engineering drawings and documents of the design presented at the Preliminary Design Review. Any changes or modifications to the design requested by the customer at the Preliminary Design Review are also incorporated before drawings are made. Once drawings and necessary documents are completed, these are sent out to manufacting houses for quote so that the customer will have a detailed price for the building of the product. I also work with manufacturers specified by the customer if they have a particular vendor that they prefer. At the end of this phase the work is summarized and delivered to the customer at a Critical Design Review (CDR). A written report is also delivered detailing everything done in this phase. Again, at the end of this phase I normally update the proposal and give firm costs for the next phase before proceeding.

Build Phase
In this phase, all the parts for the assembly are ordered, received and the product is assembled. Any kinks in the assembly process are ironed out and debugged. Bugs are sometimes surprising to many people who are new to product development because most people hear about software bugs but rarely do people hear about it being associated with mechanical or other types of projects. Most often, these are trivial and come from all sorts of areas such as a part just not being made correctly or a press fit being too tight etc. 

Overcoming bugs is large part of development and the reason why most major companies will do several revisions of a design before releasing a product to the public (alpha, beta, and release designs); especially those companies wishing to release high quality products. There should always be a buffer in an initial build of a product to allow for debugging during the build. Also in this phase, the initial manufacturing procedures are worked out and any necessary manufacturing documentation is created. Higher end or higher volume assemblies may also require specialty tools to do such things as fine alignments or to just speed up the assembly process. This would also be addressed here. At the end of this phase, fully built prototypes would be delivered to the customer.

Testing Phase
On simple projects this phase is often wrapped in with the build phase and I always do some testing of a product in the build phase before shipping a prototype to a customer. The testing can be as simple as "does it work or not?" but with more intricate assemblies this can become much more complicated as one is not just testing if it works but how well or how long it works. Tests vary tremendously on the type of product and level of quality the customer wants to achieve. These can also involve market research testing to see how well the product would be received. I work hand in hand with many customers on this phase as they usually want to be intimately involved in the testing to see for themselves how well the product works. Many times the customer takes over this phase completely. The amount of testing is most often limited by time and budget constraints.

Beta Build Phase / Release Build Phase
In the final phase a documentation package is delivery which includes detail drawing of custom components and assembly drawings with bill of matetials. For tooled parts, CAD data can be exported in a variety of formats to enable tooling directly from the CAD database to ensure accuracy and expedite the tooling process.

Often the product development cycle listed above is repeated several times mainly to iron out bugs or fix problems that were discovered in testing. The beta and release phases aren't really phases so much as a shortened iteration of the entire product development cycle. Of course, in the beta and release, the design and build phases are much cheaper and quicker to complete since one is building on a design already created instead of starting from scratch. The goal of the beta phase is usually to create a short run of prototypes that are as close to release as possible and get them into the hands of key testers, select customers or others to do some final testing before a full product launch. The release build phase is usually just to get the final bugs out of the design as production is ramped up for the initial product launch.

Mamphake Mabule
c. 2016, Mabule Business Holdings

Sunday, September 4, 2016

Small Miners | Entrepreneur

I set my sights on researching small mining operated by local small miners. I first asked the question: What is a paying quantity of mined gems? Well, when coming to gold, most small miners were satisfied with a 0.25 gram of gold per 0.914 meter, others a full gram per meter. These operations can run 1.829 - 2.743 gross meters of material an hour. Another question was: What will it take to cover the cost of equipment, the time, maintenance, and bond? The operations normally cost about R144,789.00 on average to get going, including the backhoe, vibratory screener, highbanker, long tom, water tub, water tanks, reclamation bond, and other support items. 

In some operations the equipent is accumulated over time, some were home built and designed, other equipment were purchased just for the operation. To get started, I was advised to buy second hand equipment. To go with a new backhoe and screener would proberly cost R144,789.00. Get some gold first! Whether new or used equipment, someone has got to be the mechanic. I'm always reminded that the operation involve digging the hardest packed, heaviest material all the way down to bedrock. It takes a toll on the equipment. Welding, and a mechanical background are very helpful. Daily maintenance is a must! As a draughtsman with hands on experience as a mechanic, I too had to look at the equiment maintenance reports over to be sure something simple doesn't shut down the operation early. Time for Review.....The miners sample their claims, find out what the department of minerals and energy requires for small prospecting mining claim (Notices or Plan of Operation, etc.), checked out the assest register containing all equipment, and reclamation bond. For most small miners, it took several years to fine tune their equipment and modify them to work best in the material they were processing.

I noticed tha material management was the key, whether small miners were running a small operation, or moving hundreds of meters a day. I would recommend automating as much of the material handling process as possible, Plan equipment and material handling routes. Those working creek bed, tell me that the operation quickly reclaim themselves with a good rain. The material processes from the creek generally goes toward road improvement or other necessary uses because once it is put back in the creek it becomes "dredge/fill" material that is regulated. In upland washes and benches, some would mix the size of material when refill. When leaving the fine gravels for last, it will be the first to wash off when the water is raging down the hill, and most environmental issues involve the clarity of the water. When prospecting mainly dry creek beds. Things like clay and vegetation will be a determining factor on how much area the mining operation can run per hour without refreshing the water. Water wells or boreholes are another great commodity to have close by. First, make sure the gold is in the ground, then common sense and attention to detail will go a long way toward having a successful operation.....

Mamphake Mabule
c. 2016, Mabule Business Holdings