ROLLA-V Dies

ROLLA-V adjustable

All the advantages regarding the internal bend radius obtainable with Rolla-V matrices also apply to the variable V models which, as their name indicates, have an adjustable groove opening. Each model (HD, 2, 2.5, 3 and 4) has its own parameters and Rolleri can provide special punches according to the radius to be made; unfortunately there's no universal variable size punch (yet). All adjustable models have 3 types of interchangeable inserts depending on the type of bend you want to make: flat inserts for standard folds, concave inserts for bending radius U-profiles and V-inserts for obtaining square U-profiles. The same die can make all these types of profiles just by changing inserts.

NON-STANDARD ROLLA-V DIES

Although there is a standard Rolla-V matrix for most of the applications, an ad hoc solution may sometimes be required for particular projects. Thanks to the production of each single component with cutting-edge machinery, we can produce special dies for the creation of particular profiles. Rolla-V offers a complete range of models, each of which corresponds to an die opening which is measured with the distance between the centers of the inserts. Whether you need to bend from 0,5mm / .019" to 30 mm / 1.181" thick, or you need to make a 2,7mm / .106" edge on 1mm / .039" sheet metal or a 40mm / 1.574" edge on 30mm / 1.181" thick material, there is a Rolla-V die capable of accomplish what is required. There is a range of dies with different sizes and suitable for different thicknesses: normally each model can be used for at least 3 different  thicknesses. Another characteristic is their high resistance (up to 2500 kN / m - 85 US-Ton/ft). They are tools with a special anti-corrosion coating and do not require special maintenance.

 CORRESPONDING V➀

For each model of Rolla-V die, the equivalent opening of the V in a conventional die is ​​indicated. This value is measured as the distance between the centers of the inserts.

SHEET METAL THICKNESS➂

For each model, the table indicates the series of thicknesses that it can bend. Searching on the basis of the thickness, allows to identify all the models capable of bending the selected thickness and, by checking all the following parameters, it is possible to decide the most suitable model based on the type of bending.

MINIMUM ANGLE➃

For each thickness, it's indicated the narrowest angle obtainable for the selected die

BENDING FORCE➄

The table indicates the tonnage needed to bend the indicated thickness with the selected die, here's how to calculate the tonnage:

FN (kN/m) = [(Rm x thickness²)/C] x {1+[(4 x thickness )/C]}

Aluminium: Rm=200-300 N/mm2
Steel: Rm=370-450 N/mm2
Stainless steel: Rm=650-700 N/mm2

Example: aluminium 2 mm  with model 2

FN (kN/m) = [(30 x 2²)/13,16] x {1+[(4 x 2)/13,16]}

MINIMUM EXTERNAL EDGE➅

For each material thickness, the minimum external edge that can be obtained with the selected die is indicated in the table

BEM (kN/m) = √B² /2

Example: min. External edge with model 1

BEM (kN/m) = √7.17² /2
Min. Edge= 5.07 mm

MAXIMUM EXTERNAL RADIUS➆

For each material thickness, the maximum external radius that can be obtained with the selected die is indicated in the table. By subtracting the sheet thickness from the maximum external radius, it is possible to obtain the maximum internal bend radius and therefore the maximum tip radius of the punch. It must be taken into account that during the bending process the sheet is wrapped around the tip of the punch and therefore tends to form an internal radius equal to the tip radius of the punch if its characteristics allow it.

Rule #1: RE (kN/m) = √(C² /2) - (s+Z)

Rule #2: if External radius > B/2.2, ER=B/2.2

regardless of the thickness of the sheet, the maximum external radius is a consequence of formula 2. Beyond that dimension, it is not possible to bend

Example: thickness 3 mm with model 2.5

Rule #1: 17.8 - 5 = 12.8
Rule #2: 26.34 /2.2 = 11.97
Max. external radius = 11.97

PUNCH RADIUS

In order to obtain the correct punch radius based on the external radius of the sheet, the following formula must be applied:

Models 1 e 2
Rp = (ext.radius-Material thickness) x 0,9
Models 2.5, 3, 3.5 and 4
Rp = (ext.radius-Material thickness) x 0,8