One lanky, but firm, fully flexible and adjustable arm sells for $3,990. But this arm can weld, paint, load and unload, lift and build.

And this arm, according to its creator, Collin E. Turner, combines intelligence with strength. It's an industrial air-powered robot, model L2500, that Turner's firm in Chantilly, Va., LASR Robotics, began marketing two months ago.

But it's only an arm, albeit one that typifies the race between Japanese and American industrial technology.

"People are disappointed when they see our robots," Turner said. Besides the new air-powered, or pneumatic, model, Turner's "arms" include third-generation motor-driven assembly robots.

There is nothing in the firm's large warehouse space that resembles R2D2, the walking, talking, heroic robot popularized in the film "Star Wars." The general public has to "realize that R2D2 is a nonfunctional unit" in the industrial sector, Turner said.

Industry "only needs arms. We only build arms," he said.

Turner, who first explored electronics in his homeland of New Zealand in the late 1960s, is adamant about the virtues of his simplified robot. He believes that it could be a key to gaining a competitive advantage over the Japanese, whom he said control about two-thirds of the robotics industry.

One reason the Japanese took the lead on robotics is that they developed simpler machines, what Turner calls "small baby robots stuck in a row." On the other hand, Americans went for "the top-level, sophisticated" models, he said.

"Most sophisticated robots don't work. They're too complex, too fine-tuned; just as a highly tuned car needs a lot of attention, so do robots. A quarter of a million dollar system, and if it doesn't work, you're out," Turner said.

Jeffrey Burnstein, a spokesman for the Robotic Industries Association in Dearborn, Mich., supports Turner's rationale.

Robotics "went through its gee-whiz and hype stage," he said. "Now it's in the real world."

The commercial application for these streamlined, no-hype models, mostly for the automotive and electronics industries, is now evident at robot trade shows, Burnstein said. "They don't have them shuffling cards anymore. That was the attention-getting phase. They were trying to dazzle, but it didn't translate into sales."

Card tricks aren't what Turner's robots are designed to do. They can thread needles, split a human hair three ways lengthwise, lift a huge truck frame, and -- in time -- they will be able to see. His 2 1/2-year-old company is still in its infancy, but he expects to triple its $1 million annual revenue figure next year.

Turner sees the pneumatic robot -- which runs on compressed air -- as the vehicle for LASR Robotic's potential growth. He said the firm already has taken more than $300,000 worth of orders for this inexpensive, 50-pound robot. In comparison, the firm's other robots are more than four times the cost of the pneumatic ones.

Turner, who designs the automated limbs, explained that most simple pneumatic robots had not progressed with the rest of the robotics field. Most of the advanced work has been performed on the more complex, expensive third-generation robots, leaving the pneumatic model behind as a "dumb" stepcousin, he said.

Turner's revolutionary move was to take the firm's new intelligent controller and put it in a specially designed industrial pneumatic robot. He also programmed the robot for a greater variety of movement.

Now the firm's pneumatic robot, which is often referred to in the industry as the "bang-bang" model, is capable of performing intelligent pick-and-place functions, as well as being able to sense and control its environment, Turner said. A Satisfied Customer

One customer who appears satisfied with the product is Donald J. Evard Sr., general manager of Tru-Motions Systems Inc., a Warren, Mich., firm that designs and builds automated assembly machines. Evard said he bought the unit one month ago to pick and place parts and that it has been "very effective."

Evard also said he would never consider purchasing a comparable unit from LASR Robotics' major competitor, the Japanese firm, Seico. "Given a choice, I prefer American," he said.

But, according to Burnstein, imports, especially from Japan, are increasing in number and continue to be a major concern to the domestic industry. He said it is difficult to determine what percentage of the $332.5 million worth of robots that the industry marketed in 1984 were Japanese, because the foreign firms have U.S.-based distributors.

For example, Burnstein pointed to Troy, Mich.-based GMF Robotics, which recently emerged as the dominant robotics company in the United States, and is a 50-50 joint venture between General Motors Corp. and Fanuc Ltd., a Japanese robotics company. The auto industry is by far the nation's largest user of industrial robots, he said.

But foreign imports are not the only problem facing a robotics firm the size of LASR.

Laura Conigliaro, a robotics industry analyst with Prudential-Bache Securities, said a lot of U.S. companies making robots are incurring high losses.

The robotics industry "appears extremely healthy, but the costs of building the units are exceeding the growth," she added.

Burnstein agreed that the marketplace for the robots is small compared with the number of suppliers, adding that there is a great deal of consolidation in the industry. Within a few years, there will be "a lot of suppliers who won't be around," he said.

For the robotics firms that make it through the shakedown period, however, the projected growth of the industry is strong. In 1982, there were 6,300 robots used in U.S. industry, according to figures from the Robotic Industries Association. Now there are 18,000 robots, and there could be 20,000 by the end of the year, Burnstein said. If this rate of growth is maintained, there could be 100,000 robots by 1990, he projected. Firm Set for Shakedown

Turner is confident that LASR Robotics has the grit to survive the economic filter that siphons out the weaker firms. His strategy will be to diversify into data communications, he said.

Prior to his leap into robotics, Turner founded Dyna Tech Packet Technology, a data-communications equipment company now located in Alexandria. He sold that firm 2 1/2 years ago, agreeing not to compete with its products for three years, he said.

However, in six months, Turner again will be free to develop and market products in that area -- and he intends to do so. Such diversification will allow him to purchase 20,000 microprocessors each year, compared with the 1,000 he uses in his business now, he said. He predicted that this increased volume of buying will reduce his costs by more than 50 percent.

Even though LASR Robotics' staff includes about 10 people with such functions as design, sales, electrical engineering, software development and administrative/purchasing, Turner appears to be the driving force in the main offices and at the robot factory that is located in the same industrial complex. Hard to Find Good Help

There is a "problem with good help," said Turner, who recieved some education in New Zealand and some at the University of Maryland. "I've gotten rid of 24 people in the last two years. The talent for robotics is not taught in schools," he said.

Turner talks very rapidly in an accent that has lost little of its New Zealand lilt in the eight years he has lived in this country. "People don't understand what's inside a robot. It's not just a hunk of metal.

"There's the mechanical function that gives it accuracy and precision. The robot turns around and comes back again. That's unusual. There are motors, computers and software that controls the movement of the hardware," he said.

It also takes talent to sell that complicated hunk of metal to industry. Turner touts a sale of a $50,000 system -- robots that can pick up four different parts and glue them together -- to a division of Ford in Norfolk as an example of his sales ability.

He said that Ford views robotics as a "question of survival. They understood that they had to compete with the Japs."

Turner also has discovered the other end of the spectrum, the businesses where "tempers flare" at the mere mention of the word robot. In yet another situation, he found that "employes sped up when they heard the word robotics."

While busy spreading the gospel on robots to the unconverted, Turner is undisturbed by the fact that LASR Robotics thus far has had only one profitable quarter. It has been operating on a 30 percent loss, although a two- to three-year loss was expected, he said. Turner is hopeful that the firm will start turning a profit next year.

The firm's expansion plan includes switching from a job-shop environment to an assembly plant where six robots build other robots. The assembly line already is built, and Turner expects to start it up in December. "We're doing what we tell our customers to do," he said.

Turner has no immediate plans for selling shares in LASR Robotics. "If I go public, it won't be for several years. And it would be to fund further technology and massive expansion," he said.

For now, Turner is confident that his new line of inexpensive pneumatic robots is going to put LASR Robotics way ahead of its domestic, and some Japanese, competitors. He's obviously proud of what his creation, although only an arm, is capable of doing. But he has no pet names for it. "I refer to them as it . . . . I don't think of genders," Turner said. "No, I don't even give them names."