The Importance of Prototyping Machine Parts

In the production of machine parts, prototyping is a very useful tool for a number of reasons. These can include aspects ranging from the practical to the financial, each of which can have a positive outcome for developer of the project.

One of the first reasons why prototyping is important is that the development of machine parts is necessary to create a working model of a system before it goes into production. This is essential as it takes the theoretical into the practical realm, where instead of predicting how things will function, the actual functionality of equipment can be observed.

As a result of this, in becomes possible not only to get a clear idea of the efficiency of the machine, but also any errors that occur or any faults in the initial design. Often, these kinds of errors can only be detected after a physical component is produced, and not from 2D or 3D drawings that are created prior to production.

This, of course, has significant implications for the developer of the project; if an item were to go into production with major flaws, this could not only result in the circulation of faulty products on the market, but also bear a heavy financial penalty for the developer, manufacturer and distributor of said machinery.

Producing any complex item of equipment without first developing a prototype of a machine’s parts can be financially risky in a number of ways. The circulation of a faulty item on the market can also lead to the damaged reputation of the developer of the product, and even compensation claims in some instances.

Another reason why the creation of a prototype of a machine’s parts is so important is that it gives the product developer the chance to test the equipment under specific circumstances. This could be the ability of the equipment to function for an extended period of time, or to handle various amounts of pressure and weight.

A prototype of a machine can also be used to observe how durable the item is, and whether its components are susceptible to issues when they are placed together as a whole in an item of equipment rather than being analysed simply as separate components. This model of a machine is therefore valuable to any testing and trialling of the equipment before it goes into production.

All of this analysis and testing allows the developer to move on to the next stage of production, which is another reason why this step is so important; it can act as a bridge between the early development of an idea and the advanced stages of refinement and adjustment that are necessary before finalising a design.

For those working in the contract manufacturing industry, the creation of a prototype can also improve the relationship with the contractee who has commissioned the project. The reason for this is that such a model can give the client the opportunity to see and experience not only what the product looks like but how it works too.

This is helpful for gleaning useful feedback, and also building a strong and transparent working relationship between the contractor and the contractee. It also reduces the risk that some manufacturers will face if the project owners are not satisfied with the final product.

Lastly, developing a prototype of a machine’s parts can help give the manufacturer of the item an accurate idea of the logistics of the whole production process; it becomes far easier to understand the real cost of production as well as how rapidly an item of equipment can be manufactured.

Constructing a working model of machinery has numerous benefits, ranging from problem solving to calculating the real costs of production. As a result, this stage in the manufacturing process is considered absolutely essential in order to produce best results.

Making an Educated Decision on Your Next Automated Plasma Shape Cutting Machine

Whether you are a first time buyer or have existing installations of plasma and/or oxy-fuel shape cutting systems, continuous advancements in technology and a growing landscape of low-cost manufacturers and integrators has clouded the automated plasma shape cutting machinery landscape.

Plasma cutting is the result of introducing an electrical arc through a gas that is blown through a nozzle at high pressure, causing the gas to turn into plasma and producing a focused flame that reaches temperatures of 50,000 degrees Fahrenheit. Automated plasma cutting systems are classified as either conventional or precision (high-definition), based on the characteristics of the cutting flame. Precision plasma systems are capable of producing parts to tighter tolerances, achieving faster cut rates, and producing less kerf and bevel than conventional plasma systems. The cost of these units can also be significantly higher than conventional plasma systems. It is therefore extremely important to properly match the shape cutting machine with the appropriate plasma cutting system.

One of the most common and costly pitfalls buyers encounter is when manufacturers or integrators mismatch machines and power sources. This is often the result of manufacturers not taking the time to understand the buyer’s requirements, having a limited or single-product line of machines, limited OEM access to power sources, and/or a lack of industry/application knowledge. These manufacturers will then often sell with a focus on lowest price instead of lowest cost of ownership, highlighting the strong point of the plasma system or the machine without regard to the limitations of the other. The best precision plasma power source available will not provide users with the desired cut quality and accuracy if it is not mated to an appropriate base machine.

There are many types of plasma shape cutting machines available in the market today. The most common machines are bridge or gantry style machines made from either fabricated steel or extruded aluminum. Construction of the machine is extremely important relative to your application. Machines constructed of extruded aluminum are typically considered to be hobbyist or artisan machines and most appropriate when doing a limited amount of cutting or when cutting light gauge materials. The plasma and oxy-fuel cutting processes create large amounts of heat which is retained in the materials being cut and can cause deflection or warping of aluminum machine components traveling over the hot cutting surfaces, greatly effecting accuracy and cut quality. Fabricated steel machines are highly recommended for any type of continuous cutting process, cutting of plate steel, and where auxiliary oxy-fuel torches may be used. Auxiliary heat shields may also be available to further protect the machine and components from extreme heat conditions.

Cutting machines are available with a variety of drive systems including single-side drive, single-motor dual-side drive, and true two-motor dual-side drive systems. A well constructed single-side drive system or single-motor dual-side drive system will perform extremely well in conventional plasma applications. The benefit of the extra precision offered by two-motor dual-side drive systems will not be realized in conventional plasma applications due to the limitations in the precision of the conventional plasma cutting process itself. Two-motor dual-side drive systems will provide the accuracy and performance required to achieve optimal results from a precision plasma process.

Sizing of the motors and gear boxes relative to the mass of the machine is also extremely important. Undersized motors and gearboxes will not be able to effectively change the direction of the mass of the machine at high traverse and cut speeds, resulting in un-uniform cut quality and washed-out corners. This not only affects the cut quality, but will also lead to premature mechanical failures.

The CNC control is the unit that ties together all of the functionality and features of the machine and plasma source. There are basically two classes of controls used on most of these machines today. Most industrial applications use industrial PC-based control systems such as those produced by Burny or Hypertherm. These units have user-friendly touch screen control panels and are housed in enclosures that can stand up to the harsh environments they operate in. Smaller machines of the hobbyist or artisan types often utilize standard PCs with I/O cards to control the drives and plasma systems. Industrial based controls are highly recommended for any application, are designed for industry specific requirements, are less prone to the typical PC problems, but can be cost prohibitive in smaller applications.

Another important, and often overlooked, feature to consider when selecting a machine is the construction of the rail system. Plasma cutting machines produce and reside in a harsh environment. It is therefore important that the components used in the construction of the rail system be robust enough to exist in this environment. All rail surfaces should be constructed of hardened materials and cleaned frequently so that they do not become pitted and gouged by the splatter of molten steel that will inevitably fall on them. Self-cleaning wheels are also a recommended feature to keep the wheels clean between regular preventive maintenance (PM) cycles. Sizing of the rails should also be robust enough to prevent deflection as the machine travels across them.

The combination of all of the above factors results in the precision and accuracy of a system. Unlike other mechanical machining processes, it is difficult to assign a standard tolerance to plasma cutting processes. Many manufacturers will strongly promote the fact that their machines have positional accuracy of +/-0.007 in. and repeatability of +/-0.002 in.. The fact is that just about any machine on the market can hold tolerances that far exceed the tolerance and capability of the plasma cutting process itself. There are many factors that will influence the cut quality you will achieve on your parts including: the characteristics of the part itself, power settings, consumables, gases used, material type, gauge/thickness of material, part layout on plate, etc.. Ask the manufacturer to provide you with cut samples of your parts or parts that closely approximate the parts you will be cutting, made on a machine/plasma combination that is comparable to what you are looking at. This will give you the most realistic representation of what to expect from a specific machine/plasma combination and the plasma cutting process itself.

Before talking to any cutting machine manufacturer, clearly identify your requirements:

  1. Identify the types of materials will you be cutting with your system (ferrous/non-ferrous, mild steel, stainless steel, aluminum, etc.).
  2. Identify the range of material thicknesses you will be cutting.
  3. If you will be cutting a variety of materials and thicknesses, estimate the percentage of each type and identify the primary types and thicknesses.
  4. Determine the size (length, width, and thickness) of plate you will be purchasing in order to properly size the table, effective cutting area, and weight capacity of your new system.
  5. You may also want to look to the future in anticipation of any future types and sizes of materials you may need to process. The upfront cost of anticipating these requirements may be substantially less than upgrading or retrofitting your system in the future.
  6. Identify the tolerances you will need to maintain. This will help determine whether you need a conventional or precision plasma system, as well as the type and construction of the base machine.
  7. Determine how many hours-per-day and days-per-week the machine will be operated. This will determine the type of base machine construction you will need, help estimate the cost of operation, and allow you to compare the cost/benefit of consumables life of various manufacturer’s power supplies.
  8. Determine how you will exhaust your equipment. Water tables do not require exhaust systems, but down-draft tables do. If there is an existing exhaust system in place, identify the capacity of the system in cubic feet per minute (CFM).
  9. Determine if you will need the flexibility to expand the system or add additional plasma and/or oxy-fuel cutting stations in the future. Some machines are capable of only carrying one or two torches, while others can accommodate slave stations for up to a combination of 10 plasma and oxy-fuel torches. Likewise, some machines have fixed cutting areas while others can be extended in length to increase cutting area or accommodate multiple cutting tables.
  10. Define the area in your facility where the machine will be located. Make note of any obstructions, hazards, or access points that will need to be taken into consideration when laying out the new system. Also, identify how your material will be handled in and out of the area (forklift or crane, aisle locations, etc.).
  11. Identify the power you have available, both voltage and amperage.

A reputable manufacturer should ask you for most of this information before making any proposals on a system. If a manufacturer does not have this information, they cannot adequately evaluate your requirements and propose a system that will best work for you and your specific application. Spending the time to identify your requirements up front will not only save you countless hours of frustration resulting from living with the wrong machine, but also save you money by not over- or under-buying a system to meet the requirements of your specific application.

10 Key Steps for Safe, Effective Simulation Training

There are 10 key steps for creating realistic, scenario-based, decision-making simulations. They are:
1. Needs Assessment

2. Levels of Simulation

3. Creating the Simulation Format

4. Designing the Simulation

5. Training & Controlling Demonstrators

6. Providing the Training

7. Equipment & Safety Procedures

8. Creating Multidimensional Scenarios

9. Creating Multiple-Use Scenarios

10. Debrief

Step 1: Needs Assessment

Instructors must begin the development of a simulation-training program with a needs assessment. On what do their officers need to spend their simulation training time? Although shootouts with heavily armed bank robbers need to be addressed, officers must train for all use-of-force levels. In fact, in a recent series of statewide instructor updates conducted in Wisconsin, Bob Willis, a nationally recognized trainer, found the most glaring need of the 1,800 instructors was communication skills. Train for the needs of your officers – not just the high-risk fun stuff.

Step 2: Levels of Simulation

All too often instructors go too fast, too soon in their simulation training. You can’t teach officers new skills and then, with little or no practice, expect them to do well in high-level, high-stress, decision-making scenarios. After introducing the new skills, instructors should use seven levels of simulation to prepare their officers for high-level, decision-making simulations. These levels include:

1. Shadow training

2. Prop training

3. Partner training

4. Dynamic movement training

5. Relative positioning training

6. Environmental-factors training

7. High-level simulations

Step 3: Creating the Simulation Format

Next, an instructor must work from a written simulation worksheet to provide the necessary documentation of what officers were trained to do. Besides the individual officer-evaluation form, these simulation worksheets should consist of a title page listing scenario type, objectives, overview and equipment; a page for student instructions; a page for role player instructions; and a page with a diagram of the scenario. These worksheets are essential for documenting training and can help you defend against failure-to-train allegations.

Step 4: Designing the Simulation

After the needs assessment, the instructor will begin designing the simulation, which consists of:

1. Developing the simulation

2. Choreographing the simulation

3. Rehearsing the simulation

4. Implementing the simulation

5. Debriefing the simulation

6. Evaluating the simulation

Carefully design, choreograph and rehearse your simulations, or they can lead to training injuries, the adoption of poor tactics and liability exposure.

Step 5: Training & Controlling Demonstrators

The most important component of successful, meaningful simulation training remains the development of well-trained, fully controlled demonstrators. Instructors must assign these demonstrators roles that are specific, limited and carefully supervised to prevent a deviation-from-role that can lead to poor training and injuries. Tell demonstrators specifically and in writing what they can do and, equally important, what they can’t do.

Remember: If you use officers for role players (and most of us do), they love to win. With adrenalin dumping, it’s hard for an untrained, unsupervised role player to remember that the ultimate goal of the demonstrator is eventually to lose (i.e., be controlled by the officer in the simulation). Yes, demonstrators need to be challenging and realistic, but if the trainee performs effective tactics, the demonstrator should give realistic responses and allow the technique to succeed.

Step 6: Providing the Training

Once the simulation is designed and practiced with demonstrators who understand their roles, the instructor can begin the simulation training. Follow this checklist:

1. Conduct an initial wellness check

2. Explain the training safety rules

3. Conduct a physical warm-up

4. Explain the simulation drill’s format

5. Conduct the simulation drill

6. Conduct a debriefing session

7. Conduct a current wellness check

Finally, instructors should make their training a positive learning experience. Properly explain what you expect of the student, conduct a fair, winnable scenario and properly debrief the student.

Step 7: Equipment & Safety Procedures

Although simulation training helps prepare our officers to survive and win encounters on the street, it must be conducted safely – there are no acceptable casualties in corrections, especially in corrections training. Wellness checks, training safety rules and safety procedures make this happen.

Simulation safety begins with the development of appropriate safety procedures, the development and use of safety officers, and the enforcement of stringent safety procedures. Many equipment manufacturers have developed safety procedures to use in conjunction with their equipment. Instructors should always follow these guidelines to prevent unnecessary liability.

Instructors must keep their officers safe from live-fire training accidents.

Step 8: Creating Multidimensional Scenarios

One of the most critical issues facing instructors of corrections tactics training is the difficulty in finding the time to focus on multi-dimensional scenarios that allow their officers to train for the full range of corrections responses. Most simulations now focus on using one of the use-of-force options (i.e., verbal, empty hand control, intermediate weapons or firearms). This creates two challenges: 1) Training officers to respond effectively to the approach, intervention and follow-through phases of any encounter, and 2) preventing officers from getting caught in a single force option loop, unable to move up or down the available force options.

To address the first issue, instruct officers to finish their simulation training with at least one full-length scenario that takes them from initial contact to debriefing the subject at the end of the incident. Address the second issue by teaching the officers transition drills that take them from verbal to empty hand tactics, empty hand to aerosol spray, baton to firearm, etc.

These multi-dimensional scenarios will assist officers in preventing the gridlock that often occurs when facing stressful situations because no bridges have been built between the multiple techniques and tactics officers are trained to use.

Step 9: Creating Multiple-Use Scenarios

Another challenge facing trainers: Over time, their scenarios are soon burned by their officers letting other officers know the scenario prior to taking the class. To combat this, create scenarios with multiple outcomes. Of course, over time even a scenario with a couple of different outcomes can be compromised.

To limit the number of scenarios needed to keep your officers honest, develop a subject-resistance matrix that gives all role players five separate roles, including:

1. Compliant

2. Shell-shocked

3. Physically resisting

4. Presenting a deadly threat

5. Fleeing

Once you define each one of the roles, you can easily change scenarios by switching the role player’s role. This effectively gives you five versions of each scenario when using one role player.

It gets even more fun when you add a second role player, which allows 25 separate scenario versions. This adds an exciting, time-saving dimension to your scenario training because now, instead of creating a whole series of scenarios on a certain topic (e.g., domestic disturbances), you can create one scenario with 25 separate responses. So what if the officers know we are working on domestic disturbances? They don’t know what version they will have to respond to.

Even more important, they will start to place the subjects that they deal with in these five separate categories and learn preplanned tactics for dealing with them more effectively. As an added bonus, officers start transferring these multiple lessons-learned in training scenarios to the real world. They begin to think about multiple endings for those routine dispatches and start to ask, “What’s different this time?”

Step 10: The Debrief

The last step consists of debriefing the officer’s responses in these decision- making, scenario-based simulations. Debriefing is a critical tool in changing and improving an officer’s future performance, but it’s often not done or done badly.

Debrief in a positive manner. The old way of reading the officer the riot act, telling them everything they did wrong and putting them back into line is both destructive and counterproductive. Instead, conduct debriefing in a team-building atmosphere that includes the following components:

• Are you OK?

• How do you think you did?

• Positive comment, if possible

• What would you do differently?

• Role player, and/or peer jury comments

• Instructor summation

In addition to this team debriefing or as a part of it, review a videotape of the incident. Because articulation (having the officer explain why they did the right thing) is an important part of the training process, include it at this point. Many training facilities add report writing and even courtroom testimony to this section.

Take officers out of the scenario and, prior to debriefing, instruct them to make an immediate verbal report to their supervisor – kind of like the real world. Finally, if the officer did not complete the scenario in a satisfactory manner, provide remedial training to bring them up to a satisfactory performance level. Document this remedial training.

Go beyond merely asking your officers what they did; ask why they did it. Make sure you listen to your officers’ perceptions and reasons for responding as they did prior to telling them what you think they should have done.

Several years ago, we designed a scenario that tested officers’ ability to use their firearm to stop a threat. Two officers responded to a domestic disturbance involving two brothers fighting. Upon the officers’ arrival, one brother was straddling the other on the floor while hitting him on the head multiple times with a steel pipe. The assaultive brother refused to stop. We interpreted this scenario as a clear shoot situation, but we were shocked that less than 20 percent of the officers fired their firearms. They used a whole range of other force options.

When we asked them why they didn’t shoot the assaultive brother, we received numerous answers, including:

• The subject wasn’t attacking them

• This was a domestic

• They weren’t sure what was going on

• They could have unintentionally shot the apparent victim

• The subject was turned away from them

• The baton was in the their hand

• Liability concerns

Some of their perceptions and tactical responses were very enlightening. Several ways they stopped the threat were especially interesting, including striking the assaultive brother on the back of the neck with a baton, which we thought was an innovative way to end the assault without potentially shooting the brother on the ground. This led us to ask officers in future classes what they saw and why they responded the way they did before giving our “right” answer to the scenario.

Conclusion

Document your scenarios and evaluations of the officers’ performance in the training, along with any remedial training given to each officer as a result.

Conduct safe simulation training. Ask yourself this question before an investigator puts it to you during a formal inquiry: “What would other well-trained, experienced instructors have done to keep themselves and their officers safe in this type of training simulation?”

What’s the difference between a tragedy and negligence?

Repetition.

Too many repetitions of needless, preventable training injuries and death have occurred. A developing standard-of-care exists and, as a trainer, you will be held accountable.

We need to conduct decision-making scenario training, but we must do it right.