CNC Applications Introduction
The many unique features of a PCNC create a versatility that allows it to be used in a wide range of applications. Below are some of the instances that illustrate how the unique value and features of the machine can have a substantial impact on the cost or success of an application.
Engineering Prototype, Research and Development
Too often engineers find themselves squeezed between the R&D department and the production machine shop. Here’s a typical scenario: In a CNC machine shop with high speed machining centers, the shop runs efficiently: the expensive machinery is kept busy with a well-planned job queue of production parts. Materials, machine time, tooling, jigs, fixtures, and all the rest have been carefully synchronized for continuous flow and high productivity. In the middle of it all, a wild-eyed R&D engineer shows up with a poorly documented sketch; he wants the part on his desk the next morning. Production schedules snarl with development schedules. Cost accounting is fudged, and then some people wonder why the productivity of the machine shop seems to be dropping. Sales people wonder why the new developments take so long. It’s all very Dilbert.
Personal CNC offers an alternative. Its low cost makes it perfectly suited to one-off designs. A PCNC allows engineering departments to keep a machine “at the ready”, dedicated solely to R&D work. There are many benefits to this approach. The prototype turn-around time is quicker, the product designers gain a clearer understanding of the manufacturing process, and consequently the final design is easier to manufacture when the production model shows up in the job queue of the production machine shop. Development with the use of a PCNC is more efficient, and allows a clear separation of the cost accounting of the daily conventional manufacturing processes from the costs of development.
Expensive production machines can support their high cost only when they are kept occupied in high value processes. A PCNC would not normally be considered a production machine tool, however, when it is judiciously applied in secondary operations, it can leverage the productivity of other machines.
Consider this case: a block of aluminum needs 12 minutes and 6 tools on the front side and 6 minutes with a single tool on the back side. Doing 100 pieces will take 1800 minutes. That’s 30 hours of time for the operator and the vertical machining center (VMC).
Now consider the alternative of running a VMC with a PCNC 1100™ parked off to one side. The operator passes the work from the VMC to the PCNC 1100. The 6 minutes on the backside takes 8 minutes on a PCNC 1100, but it’s done during the 12 minute operation. The total operator time drops to 1200 minutes instead of 1800 minutes. The use of the PCNC 1100 for secondary operations in this situation saves 33% on labor cost and 23% on capital equipment cost. (note below)
Because the PCNC 1100 runs on 230 VAC single phase and the PCNC 770 on 115 VAC and are easily moved with a pallet jack, the they can be moved around the machine shop for secondary operations wherever it is needed.
NOTE: Assuming we’re operating a $45,000 VMC and a $7000 PCNC and looking for 100% payback on 2 years of 1 shift operation. This is 4000 hours of operation. The VMC by itself has a machinery time cost of $11.25 per hour ($45,000 / 4000 hrs). The VMC + PCNC has a machinery time cost of $13.00 per hour ($52,000 / 4000 hrs). Without secondary operation we have 30 hours at $11.25 or $337.50. With the secondary operation setup we have 20 hours at $13.00 or $260. The machine time cost of $260 is 77% of $337.50, a 23% savings.
Short Run / Rapid Response
The conventional VMC requires a well-established G-code program for trouble-free operation. When the machinist is faced with a situation requiring short runs and rapid delivery of new designs, it simply isn’t practical to develop a full G-code program. Working in a mixed mode, with manual operations, conversational mode, and partial G-code segments, is most easily accomplished with an open machine. In these situations high-speed rapids are a liability, not an asset. A PCNC mill works exceptionally well under those conditions.
Starting a new business is always a high-risk operation. The high capital cost of fully automated equipment is difficult to justify and often impossible to finance without a proven business plan. A PCNC can get you started at very low cost. By using a PCNC instead of a fully automated VMC during startup, your business plan will have significantly lower capitalization costs and slightly higher labor costs.
This is a classic bootstrap technique: it gets you up and running and proves the plan. Once the business is established and the sales are demonstrated, it becomes much easier to justify an investment in more automated equipment.
Hobby Business / Midnight Engineer
There are few things more rewarding than developing your own product or invention. It may lead you to untold wealth, or simply keep you out of the bar. But you’ll never know unless you try.
Many people try to start a new business while keeping their day job. One of the problems of this approach is the difficulty in establishing relationships with local machine shops when you’re limited to working evenings and weekends. Your contractors will probably be unable or unwilling to meet you on your time; they may not consider you to be an important customer. You may have trouble getting what you need when you need it. However, if you can produce your own prototypes and short runs of production, you will reduce your cost, your frustration, and the time between your initial idea and final product.
The best educational tools both demonstrate theory and allow actual practice. Until the development of the PCNC 1100, the machinery designed for education limited students to working with machinable wax, plastic, or perhaps some light metals. While interesting, it allows little more than a demonstration of machining theory.
To move beyond theory and into practice requires a machine capable of performing genuine industrial processes: cutting steel, iron, stainless, and even tougher nickel based alloys. With its serious accuracy and real world capability, a PCNC can offer your students a much greater understanding of the way things work, the processes of manufacturing, and the needs of industry.
Whether you’re rebuilding antique cars, building a custom bike, or creating a homebuilt aircraft, the ability to cut three-dimensional shapes in a wide variety of materials is essential. We find it particularly odd that some people consider a $7000 tool to be just too expensive for hobby use, yet they won’t blink an eye at $10,000 snowmobiles, $15,000 fishing boats, and $65,000 SUVs. Unlike many other kinds of hobby equipment, a quality tool is an investment that has both immediate payback in personal rewards, and long term payback in high resale value. If your dream involves making things, we encourage you to make it happen.
Some people would cringe at the idea of taking a brand new CNC mill and ripping into it to make it into something else, but that very idea makes a lot of sense to manufacturing engineers. Building a new automated manufacturing system is always an expensive undertaking. However, that new system made from pieces or sections of the a PCNC is often less expensive than a line built from new, raw components. Whether it’s a single work cell or a large scale integrated line, manufacturing systems normally have precision motion with multiple axes. Because the PCNC 1100 has an open architecture, it would be a simple matter for a trained engineer to do a bit of rewiring for PLC control. Perhaps the spindle would be replaced with an adhesive applicator or ultrasonic plastic welder. Maybe nothing more than a Z axis, spindle, and column would be used. For a manufacturing engineer, the PCNC 1100 can be a building block for the creation of larger systems.
NGO, Developing Nation Programs
There are a variety of non-government organizations (NGOs) pursuing programs to advance poor and developing nations. Micro-finance and small enterprise development projects provide funding, advisors, and support for individuals and small groups with entrepreneurial aspirations. Manufacturing in the modern world is easily done with CNC, however, in underdeveloped nations the barriers hindering the application of CNC technology are enormous. Beyond the obvious financial hurdles, there are considerable problems of insufficient infrastructure. Without 3-phase power, without factory service technicians, and without spare parts sources, conventional CNC manufacturing is simply out of the question. A PCNC, however, offers modern world CNC technology, but with a design for robust operation, user maintenance, and single-phase power. Delivering the same accuracy as a conventional CNC, but operating at lower speeds without an automatic tool changer, a PCNC is the perfect machine for entry into modern manufacturing in places where labor is cheap, people are motivated, and the conventional infrastructure is weak.
We at Tormach would welcome discussion of CNC related projects in cooperation with established NGOs that may be interested in bringing modern manufacturing methods to underdeveloped nations. In our view, success would require a small cluster of machines, a supply of spare parts, and at least one knowledgeable support staff person.