Advanced Sawmill Machinery Equipment Inc. (ASM), Holt, Fla., worked with

Bosch Rexroth to incorporate aluminum cylinders with ideal cushioning in its series 140 trimmer. The machine builder wanted to offer faster cycle rates and more durability. “These Bosch Rexroth cylinders helped us to become very competitive with our high-speed trimmer,” explained ASM president David Seffens. “They’ve played a big role in opening up the 140 to 200 lugs/min market for us.”

BoschSeffens said that all the saw ladder surfaces on the series 140 trimmers are machined and keyed and require no alignment by the customer. The saw ladders do not pivot on the line shaft, which results in fewer bearings and longer service life. With the Bosch Rexroth cylinders, each machine leaving the shop is customized for speed at the request of the end user. “If they ask for a certain lug rate per minute we can set it up that way. Using the Bosch Rexroth cylinders and VTM measuring device we can be extremely precise so the trimmer is adjusted before going out the door,” he said. “And, there’s no alignment or adjustment needed for the saw ladder at installation, which means it can be installed quicker.”

Increasing speed
North Florida Lumber, Bristol, Fla., is one example where ASM and Bosch Rexroth improved a customer’s trim saw performance. Arthur Wilson, the company’s general manager, says the need for lighter equipment, reduced

downtime, and more speed played a big factor in their choice of trimmers when they were seeking to replace old equipment. The company purchased three trimmers from ASM for their saw and planer mills.Bosch

“We needed cylinders that could run fast enough,” explained Wilson, who said they were previously running 120 lugs/min. With the new trimmer he has seen substantial speed improvements, especially in the planer mill where they’re now running 140 lugs/min. “Those cylinders are fast and operate very smoothly,” he said.

Wilson said the new trimmers are expected to cut down on maintenance, too. “With our older equipment we had multiple electric motors with a lot of mass moving up and down all the time so the wear-and-tear was incredible. We constantly had to replace parts,” said Wilson. “With the new trimmers, we’ve eliminated a lot of the weight so electrical and mechanical downtime should be drastically reduced. And with the cushioned aluminum cylinders, we feel like we won’t need to replace the cylinders as much, so we don’t have to stock as many parts.”

With lighter equipment, Wilson said the company can begin using smaller blades, too. In addition, the cylinders help lower the noise of the machine. “That’s one of the things people notice is how much quieter the trimmer is,” he said.

Increasing productivity
The Valley Timbers sawmill in Antlers, OK needed improvements on an existing trimmer used for green lumber so ASM incorporated the Rexroth cylinders to help increase productivity.

“We developed a mechanical design for their trim saw so it could operate faster with lower maintenance,” explained Seffens. “They wanted to increase speed because the older design couldn’t cycle fast enough to meet the production required in today’s market.”

ASM had designed and built the original mechanical design. Seffens said Bosch Rexroth offered to put a test cylinder on the machine. The lightweight aluminum cylinders helped reduce the total swinging mass of each saw ladder, which improved ladder response.

“After running the machine through extensive testing in our shop, we found that it was better than the original design. The new cylinders allowed us to increase the trimmer speed from 120 lugs/min up to a maximum of 200 lugs/min,” said Seffens. In addition, he said the new cylinders should lower the maintenance downtime from having to replace worn out, un-cushioned cylinders.

Bill Bowlin, an industry consultant who has worked with Valley Timber making recommendations for machine design and equipment purchases, said the ASM trimmer offers several benefits. “Downtime in a mill is about

$1000 an hour,” said Bowlin. “So if a trimmer stops for some reason, the whole mill stops because all the boards have to pass through the trimmer to get out of the mill. This machine cuts the downtime and saves money. Having the ability to run faster and be more efficient is the most important aspect of being able to stay competitive in our market,” he said.

For more information, contact Bosch Rexroth Pneumatics at (859) 254-8031 or visit www.boschrexroth-us.com.