Doug West made a deal with the front office. As Machine Shop Manager for Micro Systems, Inc. (Ft. Walton Beach, FL), West proposed the following idea to management: Authorize the purchase of one CNC mill with an SFP (Shop Floor Programming) system and within 6 months we can manufacture all our own parts. We will be completely self-sufficient. We will no longer have to pay big bucks every year to outside job shops, wait two weeks for turnaround on a prototype only to immediately make more changes to it, and we will be able to improve our part quality because we will have more control over the manufacturing process. The front office was skeptical but willing. They authorized the purchase. After 3 months of extensive research and evaluation, the machine they selected was a Fadal VMC 20 mill with the 32MP control utilizing CNC Visualizer® SFP software (on-line). Virtual Gibbs®, (Gibbs and Associates, Moorpark, CA) a companion programming system, was purchased for off-line use.

That was six months ago. Since then, West has programmed and cut over 300 parts with the machine/SFP system. Micro Systems, Inc. has successfully made the transition from subbing out 80% of their work to manufacturing all of their own parts in-house. They have achieved this with increases in both productivity and part quality, at a lower cost.

Micro Systems, Inc. designs and manufactures drone control systems, ground training target control systems, energy control systems, and test equipment for the military and its prime contractors. "Our primary business is aerial target drone command and control systems. For weapons testing, the military needs unmanned vehicles for live missiles and air defense artillery firing," explains Cort Proctor, Director of Marketing at Micro Systems, Inc. He continues, "We provide the airborne avionics packages that allows you to fly both sub-scale vehicles and full size fighter aircraft by remote control."

A company of 77 employees, Micro Systems, Inc. currently designs all their own hardware and writes the software for these systems. Up until March 1993, they contracted out 80% of their manufacturing work to outside shops. Outfitted with only manual machines, they were forced to send out any parts that required a CNC machine for manufacturing. Doug West explains, "We were paying over $300,000 a year to outside job shops. Quality was a growing concern. We have to hold several very tight tolerances: geometric tolerances, flatness requirements, finish tolerances, etc. It was hard to find a contractor that was willing to take a risk on a part like that for a reasonable price." Turnaround times were another problem. West says, "During the prototype stage of a part, there was an average two week turnaround time between drafting, engineering changes, and correcting mistakes until we got a good first part."

West recognized that there was a better way. Already staffed with skilled machinists, if Micro Systems, Inc. purchased their own CNC machine they could bring the CNC work in-house. "We would be able to set our own schedules and meet our own deadlines. We would have more flexibility with the R&D work. We could make the changes and improvements immediately."

West knew what he was looking for, a high quality CNC mill with state-of-the-art programming capabilities. He wanted an SFP system that would allow him the flexibility to program parts his own way, without being locked into canned cycles and routines. He wanted a system that would be easy to edit and make engineering changes on the fly. He wanted to make sure that the machine and programming system held the required tolerances and quality that in the past had won Micro Systems, Inc. the Air Force Blue Ribbon Contractor status. And he wanted to be sure that although it was a powerful system, capable of handling their most intricate parts, it would be fast and easy to use. A Fadal mill with the CNC Visualizer SFP system won the selection process. In addition, they also purchased Virtual Gibbs, the off-line companion programming system for Fadal SFP, to run in the programming office. The synergy between using the two systems in tandem has helped create substantial productivity gains.

Much of the actual part programming is done on the off-line programming system using a 486 PC. For all but simple parts, West finds it more comfortable to program seated at a desk, rather that standing at a machine in a noisy shop. The graphic CAM file for the part is then transferred to the CNC machine via either the RS232 hard wiring, or by a 3.5" floppy disk. The benefit of the complementary systems becomes evident during the set-up and editing phase, at the machine.

As in any machine shop, all the editing and optimizing of the part program is done at the machine control. However, because of the on-line programming system (CNC Visualizer), the set-up man is not forced to work with cumbersome G-codes. He is able to edit, change and optimize the part program using the graphic SFP capabilities. What is the benefit? Let's look at part program set-up in a shop without SFP/companion off-line capabilities:

An NC programmer programs a part with an off-line CAM system to create a CAM file for the part. He "post processes" the CAM file to create the G-code text part program which is given to the set-up man. The set-up man spends a day setting-up the job to run. He debugs the program, makes small changes, adjusts the speeds and feeds, moves a couple of operations around, etc. He makes all these changes to the G-code part program directly, a very time consuming task, fraught with the significant probability of human error. Missed minus signs and dropped decimal points happen all the time in the editing of G-code part programs. Finally, the program is de-bugged for these errors, set-up and ready to . Keep in mind that none of the changes made to the G-code program have been made to the CAM file it was created from. Then comes the first Engineering Change Order (ECO). A change in the thickness of an inside wall.

The NC programmer makes the change to the original CAM file, re-post processes it and sends the new G-code part program back out to the machine. The problem is that the changes the set-up man spent a day making are not in the new G-code part program. The original CAM file was never updated with all the changes made on the shop floor. A very common problem. Now, the set-up man must back and make all those edits to the G-code part program again, compounding the probability of human error once more. He must duplicate the work he did the day before, and although he might be a little faster at it this time, it is still redundant work and a waste of time and money. Then comes the second change, and the third, and the fourth. Four or five ECO's are not uncommon in a first run job. If not ECO's then tooling and fixturing changes. Although this is the way the set-up process has been done since the advent of the CAM system, the failings of this method are obvious.

The alternative is simple. A Shop Floor Programming (SFP) system with a companion off-line system. SFP is a CAM system that has been tailored to work well in the machine control. It is not just an off-line CAM system that has been copied to the hard drive of the control's computer. It is designed to program parts quickly and easily at the machine control. The companion off-line system is basically the same software package with perhaps some increased functionality; it runs on an off-line computer in the office, or at home. There are several benefits to this.

The programmer uses the off-line system to create the CAM file. It is then sent to the machine. As the set-up man optimizes the program, instead of working with G-codes, he can work with the part graphically, in exactly the same manner the part was originally programmed. He can graphically verify each change, and significantly reduce the risk of human error, because the control does all the number crunching. He can make adjustments to the actual part file, as opposed to hunting through thousands of lines of text to change a feed rate. This saves time and reduces errors tremendously. More importantly, since all the changes have been made directly to the CAM file, when the next ECO comes through for that part, the programmer uses the updated CAM file to make the adjustment, and all the changes made at set-up are in the file, ready to . There is no duplication of work by the set up man.

The results of this unique approach to companion SFP and off-line programming systems have reaped rewards for Micro Systems, Inc. in several areas. "The decreases in turnaround times have been quite extensive," reports West. "The flexibility it has given us in scheduling has helped us turnaround prototypes much faster." He continues, "Graphic editing is much faster that G-code editing. To change anything physical about the part it is going to take at least a half hour to an hour to in and G-code edit. To graphically edit the same change would take a maximum of five minutes. Then you post process it and you are back up and running with a good part. I think what I like about the system the most is that has taken the tediousness away from programming."

The amount of training time to get the system running was a surprise to both West and the front office. "We were expecting a two week learning curve before we would have it running. But, within two hours of having the machine plugged in, we were cutting parts and we have yet to scrap a part!" remembers West. "We've been very careful, but with a machine shop background it's a very easy machine and programming system to use."

West certainly proved his point to the front office. Micro Systems, Inc. has saved time and money by manufacturing their parts in-house, and they have increased control over their scheduling and part quality. In fact, the experiment was so successful, Micro Systems, Inc. plans on purchasing additional CNC machines to further expand their capabilities. "We may, in fact eventually become a job shop ourselves and add another profit center to the company," reports West. In closing, he remarks, "I very highly recommend a machine and systems like this for both production and prototype shops. Even with small runs this has been a very big improvement."