The Bay Area’s growing manufacturing sector is often portrayed as the region’s last best chance to bring back some of the well-paying, blue-collar jobs that have been disappearing for decades.

But entrepreneurs at the forefront of the so-called “modern maker” movement — nimble boutique companies crafting everything from robots and drones to custom eyeglasses and backpacks — say there is a problem with this vision: a lack of workers trained in the necessary skills.

While nonprofits train low-income Bay Area residents for jobs in fields like health care, construction and tech support, these leaders say, there’s no similar forum to become proficient with the tools of today’s makers: computer-controlled lathes and mills, laser cutters, injection molding machines, 3-D printers.

Seeking to fill this need, Ryan Spurlock started the San Francisco nonprofit Humanmade, part of a planned project at 1 De Haro, a 130,000-square-foot development at a former gravel operation on the edge of Showplace Square.

In addition to 86,300 square feet of office space, the complex would have 43,400 square feet of so-called PDR — production, distribution and repair. The Planning Commission is scheduled to vote on the project Thursday.

Using 10,500 square feet of space on the first floor and mezzanine, Humanmade would offer a metal shop, a wood shop, both automated and hand tools, and digital production equipment, including 3D printers and laser cutters. The nonprofit plans to provide affordable access to these machines along with classes, job placement services and business development training.

“We are trying to help folks gain access to modern manufacturing jobs in the Bay Area. There are more manufacturing jobs than ever and a lot of companies are struggling to fill them,” said Spurlock. “People can come in with little to no skill and learn how to master modern manufacturing.”

The concept is simular to TechShop, a maker center in San Francisco that filed for bankruptcy last year. But unlike TechShop, which Spurlock helped run, Humanmade will not have to make a profit. The seed funding came from SKS Development, the group behind 1 De Haro.

“He is talking about democratizing access to these skills,” said Daniel Kingsley, managing director of SKS. “It just feels like now it’s not democratic because you have to know people, and you have to have money to take classes.”

Bay Area makers say Humanmade will meet a pressing need. Zack Johnson, product manager for OpenROV, an underwater drone maker that got its start at TechShop in 2012, said few workers are comfortable with things like laser cutting and 3D printing.

“There is a huge gap between the workers trained in a large-scale manufacturing and the inventor guy tinkering in his garage,” said Johnson. “That is the gap Ryan is trying to fill.”

Espen Sivertson, an entrepreneur in 3D printing, said Humanmade will create an ecosystem where aspiring makers can get trained and connect with like-minded people.

“It’s an emerging space,” he said. “We are digitizing manufacturing and that has consequences. You don’t need a master’s degree in engineering to use the equipment, but in order to get into it you need spaces where the barrier to entry is lower.”

Marc Roth, who has been involved in several maker start-ups, was staying at a homeless shelter in the Tenderloin when he first walked into TechShop. Within six months, he was teaching courses there. Within a year he had started several companies, including a laser cutting firm. He said Humanmade “will take the best of TechShop and bring it under a new umbrella.”

“It will be a diverse and rich community where people can help each other,” he said.

If 1 De Haro is approved, it will be the second building — the first is 150 Hooper St. — taking advantage of Supervisor Malia Cohen’s legislation that allowed developers to build office space in areas not zoned for it, provided that one-third of the square footage be set aside for affordable manufacturing space.

The 1 De Haro property — a triangular parcel that consists of sheds and a large storage yard, was formerly home to the San Francisco Gravel Co., which shut down in 2015. The Nicolai family had operated the company from 1930 to 2015.

SKS Project Manager John Fisher said that while selling gravel is no longer an efficient use of space in a dense neighborhood that borders Mission Bay and Showplace Square, the Nicolai family wanted to create something that would last another 80 years.

“The business of San Francisco Gravel is done — the next generation wasn’t interested in carrying it on,” said Fisher. “But the family recognized that there was still value in the land. They wanted to create a legacy family asset.”

J.K. Dineen is a San Francisco Chronicle staff writer. Email: jdineen@sfchronicle.com Twitter: @sfjkdineen