Steve Brown is bending product manager,  Wilson Tool International.Click image to enlargeby Steve Brown 

 When left to their own devices, press brake operators come up with all sorts of creative ways to curb deflection, aka the “canoe effect” when bending longer parts in the press brake. Often, there are so many scraps of paper or cardboard left behind from repeated efforts to shim the die to achieve a consistent angle that their shop looks like an elementary school craft project went awry. 

The reason for this is that any time you are bending a part over four feet long on a press brake that part is susceptible to deflection. A result of uneven downward pressure combined with slight nuances built into the machine itself, deflection occurs when more tonnage is applied to the ends of the beams than in the centre. This causes the angle of the bend to be tighter on the left and right and less so in the middle, creating a bow in the bend angle. 

A common method for countering the “canoe effect” is to manually shim press brake dies using folded paper or cardboard in order to offset the deflection. However, doing so requires a significant amount of trial and error resulting in costly downtime. And once a solution is found, it’s not easily repeatable the next time you need to perform the same bend, which means you’ll waste even more time tinkering to find the same solution over and over again. 

Wilson ToolsClick image to enlargeFortunately today, press brake crowning systems are available from the machine OEM and aftermarket suppliers that take the guesswork out of correcting sheet metal bowing. Crowning systems are installed in the lower beam of the press brake to offer precise crowning and micro tuning of the die. Crowning adjusts the beam up to 3.5 mm (.137 in.), depending on length, with available micro adjustment at points every 200 mm (7.87 in.) on the beam for fine-tuning up to 5 mm (.020 in.)

Not only are crowning systems faster to set up and more precise than manual shimming, the results can be repeated setup after setup with no tinkering required. 

Crowning systems generally have two key features: a method to hold the die and a way to control deflection. Die holding can be accomplished with set screws every inch along the beam for manual tightening or with hydraulic actuation.

Deflection is controlled using either a manually adjustable hand crank for overall height control and digital display to measure movement. Or crowning can be adjusted via the machine control using a CNC controlled electric motor. 

Producing consistently straight bends in long parts shouldn’t be a game of guess and check, where the operator with the most creative solution wins one round, with the answer for the next round being anyone’s guess. 

Instead, installing a crowning system will eliminate the guessing game and improve your press brake profitability by significantly reducing unnecessary downtime and producing consistently higher quality bends. SMT

Steve Brown is bending product manager, Wilson Tool International.

WATCH: Smartphone manufacturing in China

OPPO has come out with its flaghip Android smartphone the R11. Watch how the phones are made at the OPPO factory in Shenzhen.

Customized Tooling

by Mackenzie Froats

Why customized indexable tooling may be a good option for your machine shop

Tech Tips: Machine effects on a formed section

by Jack Pennuto Jr.

Roll forming machines impact process quality

$40 M for advanced manufacturing in Ontario

The Ontario government has announced it plans to invest $40 million in advanced manufacturing inititatives in Ontario. The funding is part of a broader provincial $400 million Business Growth Initiative aimed at supporting Ontario's shift towards a high growth innovation economy.

TRUMPF, partners win research prize for laser technology

TRUMPF, Bosch and the University of Jena have won the German Future Prize for their work on ultra-short pulse lasers for industrial production.

Laser smart

by Mary Scianna

The Problem: Inability to meet rising production levels

The Solution: Automated laser cutting

Laser automation meets shop's production demands and innovative work schedule

Physics busters

These ten objects seem to defy the laws of physics.

Fiber laser cutting: Beam Me Up

Everything about fiber laser technology is fast, forcing the rest of production to keep pace

Digitalization of the Machine Shop

by Jeff Rizzie

Improve your competitive advantage

Automated 90 degree cuts

Scotchman’s Auto-90 program option makes the SUP-600 AngleMaster a completely automatic machine for 90° cuts.

A Few Words to Describe 2020

è

During the past eight months I have heard this year described in a vast number of ways. I won’t list them, but a lot of them were fearful, most of them were cautious, many of them colourful and almost all of them decidedly negative. 

Growth Strategies

By Ed Robertson

The problem
Repositioning job shop business

The solution
Investing in new equipment, technical know-how

Slowly but Surely…

by Michael Ouellette

Auto-Darkening Filters for Welding Helmets

Weldcote’s auto-darkening filters feature clear, true-colour blue, high-definition technology that enhances the visible spectrum for optimal clarity and reduced eye fatigue.


A Bright Future

Article by Kip Hanson | Photos by Deny Cardinal

Rapidly growing fab shop buys the first machine of its kind in Quebec

THE PROBLEM: Standing out from competitors
THE SOLUTION: Fiber laser cutting technology

Stay In Touch

twitter facebook linkedIn