Robots that learn
September 16, 2021 | 4:05 pm CDT
Training a spray finishing robot

Will Sampson teaches a Lesta USA robot how to spray a stool. You can see in the side-by-side video linked below how the robot mimics every action, even his mistakes.

Facing the continuing challenge of finding skilled workers, more and more woodworking operations are looking at robots for help. Everybody at the AWFS Fair in Las Vegas was talking about it. Even some of the smaller shops were stopping to look at robots and ask questions.

It all reminded me of the early days of CNC manufacturing in woodworking, when crowds gathered to watch CNC routers in action although few were ready to buy right away. Then and now, one of the big barriers has been programing. How do I program these automation tools? Do I need to hire people or go through extensive training to get it done?

But technology has come a long way in the last 20 years. At AWFS, I was able to program a finishing robot from Lesta USA. I don’t know anything about coding or programming a robot, but I do know my way around a spray gun, and it turns out that’s all I needed to know.

Self-learning robot
The Lesta USA finishing robot is designed to learn from skilled human finishers. It learns to mimic all the operations of the human finisher, including trigger action, gun position, speed of application, position of the part to be finished, and other subtleties of the finishing process. 

Programing the robot is really simple. You grab the spray gun on the end of the robot’s arm and manipulate the gun just as if you are spraying with a live gun yourself. The self-learning robot records everything you do with the gun and any changes you make to rotate the part at the same time. As soon as you are done, the robot can play back exactly what you did.

How it works
I was initially skeptical of how closely the robot could follow a trainer’s action. Lesta USA invited me to give it a try. I have to say that it was really amazing.

I don’t spray daily as once upon a time I did, so I felt a little rusty moving the spray gun to spray a challenging piece, in this case a stool. The proof of the success of the programing was in watching the robot duplicate everything I did, including my mistakes. I cringed as I watch the robot masterful duplicate everything I did wrong.

The experience opened my eyes to the potential of robots. The folks at Lesta USA noted that the idea is not to replace skilled finishers with robots but to train the robots to do repetitive tasks so skilled finishers can tackle more demanding projects. It’s definitely worth checking out to see if robotic finishing works in your operation. Learn more at


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About the author
William Sampson

William Sampson is a lifelong woodworker, and he has been an advocate for small-scale entrepreneurs and lean manufacturing since the 1980s. He was the editor of Fine Woodworking magazine in the early 1990s and founded WoodshopBusiness magazine, which he eventually sold and merged with CabinetMaker magazine. He helped found the Cabinet Makers Association in 1998 and was its first executive director. Today, as editorial director of Woodworking Network and FDMC magazine he has more than 20 years experience covering the professional woodworking industry. His popular "In the Shop" tool reviews and videos appear monthly in FDMC.