Insourcing Prototypes

Softronics Avoids the Long Line for the Machine Shop with DIY CNC

Small engineering firms like Softronics, Ltd find themselves in a delicate situation when building new products. Customers expect their custom radio components in a timely manner, but Softronics found it had to wait in line at the local machine shop to get the prototype made. With other large electronic builders in the Cedar Rapids area, fab shops found it easy to postpone a one-chassis job.

“If you take a one-off to an outside machine shop, you’re going to face the infamous N.R.E.,” explains Jon Byerly who now heads up in-house prototype production at Softronics. “It’s a non-recurring expense for them to generate the g-code to make one prototype. Most of the shops here are doing big jobs for Rockwell-Collins and are not terribly interested in your little electronic part. You’d have to wait until they have a lull.”

Robert Sternowski, President of Softronics, saw outsourcing of CNC cutting was eroding the company’s advantages as a small lab – its responsiveness and flexibility to customer needs. “We were getting totally frustrated with the local machine shops. Good as they were, the one-piece prototypes were prohibitively expensive, typically $1000 per part, and the shops would only do them when they ran out of other better paying long-run jobs. So despite the fact that we could design and build an entire new radio in eight weeks, we were getting killed by their lack of service to small businesses like us.”

The situation of Softronics sounds familiar to countless inventive small businesses. Fortunately, there now is a practical alternative waiting in queue. Recent availability of affordable new CNC technology capable of professional results provides a new path for prototyping. Sternowski purchased the Tormach PCNC 1100, a revolutionary mill design released in 2006 which fills the midsize gap in the CNC market. The machine costs only $6800.

“We invested in a Tormach, the only new piece of major machinery that we have ever bought, and it paid for itself after the first eight or so parts we made,” says Sternowski. Softronics already had engineering software on hand with the capabilities to translate its 3D product models into CNC g-code. Adding CNC machining tools at Softronics turned out to be easier and far less expensive than expected.

According to Byerly, who operates the mill, the result has been extremely quick turnaround on new products. “Once I get the drawing, if it’s not terribly complicated, I can sometimes turn it around in less than a week. That includes making sure the g-code is correct doing the actual machining and correcting any mistakes,” he says. Typically, Softronics produces two to four new products every month.

“The Tormach mill fills a very unique position in the hierarchy of machine tools,” says Byerly. “It fills a very unique void right in the middle between the hobby machines and the industrial mills.” Previously, the CNC market had been split between fastproduction machines, which run in the hundreds of thousands of dollars, and small desktop routers for hobbyists.

It was not an accident that the mill fit perfectly into the needs of R&D and the small business budget. It was by design. “We set out to design a mill that was especially designed for prototyping and short-run production,” says Tormach CEO Greg Jackson. “We call the concept Personal CNC because of the strong parallel we see with personal computers."

Jackson and his Wisconsin based engineers spent three years developing the optimal platform of spindle speed and rigidity to produce a CNC capability tough enough to fabricate almost any mechanical part. With a cast iron frame, the 1500 lb PCNC 1100 is large and sturdy enough to make smooth cuts through anything from easily machined polymers the toughest nickel-chrome alloys, yet is small enough to sit comfortably in an individual’s workshop. The electrical platform does not require industrial current, so the machine can operate in a light industrial space or in a residential garage through a standard dryer outlet.

“We looked around at prices of used mills, found the professional grade machines to be pretty pricey, even used,” recalls Sternowski. “They required a large investment involved in support, and having to work with fairly primitive older-generation software and interfaces compared to newer machines, which were out of our price range. After doing quite a bit more reading, we decided that the Tormach was a good investment.”

The Tormach’s rigidity makes it able to take not only heavy-duty cuts out of metal, but also the high-precision delicacy of radio circuitry. Many projects in the Softronics are miniature radios for DoD or government applications. Commonly, the radio instruments use frequencies in gigahertz -- close to radar or microwave range. This requires Bylerly to cut traces as small as 10 mils (0.010 inches) and make tolerances even twice that small. Such tasks could not be done on a desktop CNC. On the smallest parts, the machinist maintains plus or minus 1 thousandth of inch (0.001") accuracy.

“Hand in hand with the rigidity goes precision,” says Byerly. “Small motors on minimills have a tendency to burn out quickly, and even if they’re operating at 100 percent, it does not have the precision of the Tormach.”

The compromise that the mill makes to keep its cutting power and precision at a very low price take is in the rapid speed. This is the speed used to move from one cut to the next. With a rapid limit of 65 inches per minute, the Tormach mill will take a bit longer on some jobs. For one-off work, a few seconds do not matter so much, considering the prototype doesn’t have to wait three weeks in line.

“The PCNC 1100 is not designed for heavy production milling, like a Haas. But for the money, it’s the best that you’re going to do,” explains Byerly. “If you don’t do any heavy-duty high-speed industrial jobs, the Tormach can do pretty much everything you could possibly want, and does it extremely well. For the money, it is probably the best value out there, unless you want to spend 4 or 5 times as much and buy a Miyano or a Haas. If you have a small budget, the Tormach’s the only way to go.”

About Softronics, Ltd.

Softronics Ltd. is a veteran-owned small business engaged in the design and manufacture of state-of-the-art electronic equipment and systems for both commercial and government markets, specializing in radio systems for any application. Its staff has nearly 500 years of combined experience in the design, manufacture, and support of sophisticated electronic products and systems in both ISO-9000 and MIL SPEC environments. For more information, please visit: www.softronicsltd.com.