WITH MACHINES LIKE THAT... WE CAN USE YOUR HELP!

By: Ed Brown, President

Manufacturing Dynamics, Inc., Chino , California

We know that modern day military and commercial aircraft require a variety of complex structural parts. As such, there are thousands of parts that require multi-axis NC machining. Bidding is tough in this area as many machining companies bid in a very competitive market for the hard-to-get long term contracts that are now in vogue. In the small parts arena, hundreds of machine shops compete for the contracts being let. However, as parts become larger, competition becomes scarcer as the number of machine shops that can effectively compete are no more than a few dozen... and with many of them operating at or near capacity, it becomes less competitive.

The question is not 'Who is my competition?' but rather 'Are we competent enough to build the part?' We knew that we had purchased the right equipment when we were told by the representative of a large aerospace manufacturer. 'With machines like that, we can use you guys!' The machines being commented on were two new Mighty VIPER vertical machining centers.

STARTING FROM SCRATCH

Manufacturing Dynamics is a relatively new start-up machining company with years of experience behind the founders. Starting a machine shop from scratch is rough in this day and age as so much is required to get things going. First of all, one doesn't just run out and buy big capacity machining centers. Because of our experience we knew we had to have extensive NC programming ability and a tract record in delivering parts.

We started out with smaller machining centers and developed our NC programming expertise in order to get things going. CAD programs used are Computervision and CADKey. CAM programs are MasterCAM and BobCAD. With two programmers on the staff, this gave us adequate technical help in developing our NC programs. With smaller NC machining centers, we were able to prove our parts manufacturing capabilities, as well as the ability to meet delivery schedules.

After a year of proven operation, we decided that it was time to increase machining capabilities by acquiring larger machining centers. Researching which machine to buy is rather straightforward. One wants a machine that is reliable, easy to operate and maintain, accurate, and reasonably priced. One more important factor is, 'What is the delivery schedule?' Of course company literature is necessary for machine statistics, but we also wanted to talk to and visit existing owners.

The machines we decided upon were from Mighty USA, Torrance, California. Their VIPER VMCs, models VMC-2100 and VMC-3100 were just what we required in order to expand. After visiting a machine shop in Long Beach, we knew that these machines had the muscle we needed to expand our business. The unit we observed was a VIPER 2100 and it was being used to machine titanium and aluminum, and was especially adept at 'hogging' large slabs of aluminum. This was important, because our customers cannot wait for the long lead times necessary for large aluminum extrusions. It is actually more economical in the long run to machine many of these parts, especially since many extrusions require machining operations performed on them anyway.

The first machine acquired was VIPER 2100. With its 83" x 41" table, this machine filled a niche that other manufacturers did not offer. This heavy duty VMC has a heavy duty Meehanite casting, making it a very solid machine. In addition to its solid frame, the VIPER 2100 uses large ballscrew assemblies from maximum rigidity ad precision. The ballscrews are located in the exact center of each axis, which effectively eliminates heat and lost motion. High torque AC servo units are directly coupled to the ballscrews, moving the axes faster and with more precision. Equipped with Mitsubishi AC digital motors, cutting time is minimized with the high reliability and precision movement. Likewise, its arm type automatic tool changer is one of the fastest in the industry.

Once the VIPER 2100 was up and running, we had its bigger brother, VIPER 3100 delivered. The VIPER 3100 is the toughest and one of the largest C frame VMCs available on the market. Its table size is 38" longer than the 2100, enabling us to machine some fairly long pieces. Like the VIPER 2100, it is built on a heavy duty Meehanite casting to ensure maximum rigidity. The column, bed and saddle are oversized, fully ribbed and can easily support heavy loads without table deflection. The 3100 is ideal for aircraft profile machining and features large box ways.

Both machines feature the Mitsubishi Meldas 530 CNC 3D graphic controller with a 32-bit CPU. Featuring multi-window capability, the controller utilizes user-friendly interfacing and is a leader in establishing operator ease and performance.

The arm type automatic tool changer is random and bidirectional to minimize tool change time. The magazine for both the 2100 and 3100 holds 30 tools, accepting tools with a maximum diameter of 5" and a maximum length of 12" and weighing up to 33 pounds.

Acquiring the VIPERs was a Mighty big investment for us to make. However, after all of our preliminary studies including interviews with other users were completed, we felt fairly secure in expecting some Mighty big dividends as a result of this major investment. While time till only tell, indications are from our initial operation of the units, that this should be a 'slam dunk'!