Monday, June 24, 2013

It looks Flat, but does it stay Flat? Adjusting Precision Hydraulic Roller Levelers

A precision roller leveler will produce flat sheets from coiled steel.  If the leveler is not adjusted properly, stress can be induced in the material causing bow in the end product.

Bradbury edrive precision roller leveler

Hand cutting strips with plasma for burn test

The picture (right) shows a burn test on .250" X 72" hot rolled steel X 46 KSI yield. With all of the back ups flat, the leveler was producing flat sheets. However, after the burn test was preformed, the strips showed upbow on outer edges.

After burn test before leveler adjustments
Close up view of edge bow

The leveler was 96" wide so the #1 and #7 backups were outside the material stripwidth.

Adjustments made

Lowering the #1 and #7 entry backups improved the bow, but did not eliminate the problem. 

The next adjustment was to lower the exit #1 and #7 backups which resulted in a flat sheet in all directions and produced good laser material.

This proved that the machine is under an even load where material is being worked. The cylinders that do not have material over them and are not lowered away will put upward pressure on the edges of the coil causing stress to be induced in the coil.

Steel strips after adjustments made on the leveler
Outside strips of leveled material after cut

The Solution

The operator must know where the material is in the leveler and lower the entry and exit backups that are outside of the strip width.  

To make this adjustment easier, new Bradbury Leveler Controls will display where the material is running on the control screen allowing the operator to make adjustments right from the console.

Material position in leveler is now designated by green numbered backups

Leveled steel sheets
Do you have questions about your leveler or coil processing line? Give us a call at +1-620-345-6394 or contact us by clicking the button below or visit our download page for more technical information.

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