I worked on some edge-banding machines during my time at Biesse. These machines applied glue and wood veneer or plastic edging to plywood, particle board, and fiber board to make the edges pretty. The first section of the machine utilized cutting wheels to trim a small amount off of the edge of the board. Glue was applied to the edge, and then a strip of plastic or wood veneer was pressed against the glued edge. A pressure roller had to be positioned to match the thickness of the edge-banding that was applied.
One machine had a problem. The pressure roller was contacting a guide, which was wearing a groove into the roller. I was assigned to go to the customer to correct the problem. One of our senior engineers told me that the problem was the mechanical adjustment of the pressure roller.
I went to the customer site, checked the pressure roller adjustment, and found it was correct.
The machine had a start-up sequence, which included the depth-setting of several sections. The pressure roller setting was adjusted by advancing the depth slide, then positioning spacers for the thickness required, followed by retracting the depth slide against the spacer(s). During production, another cylinder extended the pressure roller to contact the edge-banding and press it against the board. I observed the start-up sequence and noticed that both cylinders were advancing during the depth-setting. The depth slide was extending full stroke, which is past running depth, and the pressure cylinder was also extending, which caused overextension, and the roller was then contacting the guide.
I notified the senior engineer of what I had found, and he told me that I was wrong, that I didn’t understand, and that it was a mechanical adjustment.
Another engineer was later sent to the same customer to check on the machine, but did not check the roller adjustment while he was there.
I left Biesse shortly afterward, and I don’t know if the machine was ever actually fixed.
Readers, do you think our Sherlock was correct in his assessment, or was the senior engineer correct in this case? Tell us what you think, and how you would solve this problem, in the comments section below.
Glenn Aitchison's first field service job was in 1987. Since then he has worked in the robotics, automotive, and industrial automation and machinery industries. He received his Certificates of Qualification as an Industrial Electrician and as an Industrial Mechanic (Millwright).
Tell us your experience in solving a knotty engineering problem. Send stories to Rob Spiegel for Sherlock Ohms.