BENDING WITH BALL MANDREL AND WIPER DIE

When the radius of the bend is smaller and/or the wall is thinner, it becomes necessary to use a

ball mandrel and wiper die. The wiper die is used to prevent wrinkles. The ball mandrel performs like a plug mandrel. The balls are used to keep the tube from collapsing after it leaves the mandrel shank.

Bending issues are enlarged when making tight bends or with thin wall tubing. It becomes more difficult to retain the material during compression.

The pressure is so intense the material is squeezed back past tangent and buckles. This area must be supported so that the material will compress rather than buckle; this is the prime purpose of the wiper die. Note, the wiper die cannot flatten wrinkles after they are formed; it can only prevent them.

Bending thin wall tubing - requirements for the bending of thin wall tubing with tight radius bends of centerline radius equaling the tube outside diameter have become more common in recent years.

To increase the problem, new alloys have been developed that are extremely difficult to bend. The proper bending machine, good tooling, and a trained operator can make all the difference.

To facilitate this type of tube bending, the material to be bent should receive special consideration. To help maintain the consistency of the tubing dimensions and characteristics, the entire material required for a given job should be acquired from one supplier, preferably even from the same lot or heat number. Premium-priced close-tolerance tubing should be considered. It often saves many more times its added cost. It may be necessary on occasion to size certain tubing before bending.

There are many pipe bending machines but only a few are capable of thin wall, 1 x D bending.

Even those machines best suited for this special bending must be in excellent condition and of a size large enough to assure rigidity. The machine must be capable of retracting and advancing the mandrel with the clamp and pressure dies closed. A hydraulically actuated pressure die is desirable. One feature of this system is that it provides identical pressure on the tube regardless of wall variation.

A pressure die boost counteracts the drag of the pressure die, mandrel and wiper die. It pushes the tube into the bending area, preventing excessive wall thin out.

Without a pressure die boost, the thinning that normally can be expected is about three quarters of the elongation of the outer wall. Companies specialized in steel bending automation for a broad array of fabricated products, includes CNC tube benders, tube measuring equipment and complete cellular integrated systems.

TUBE BENDING

The most common processes for bending pipe and tube are: ram, roll, rotary-draw, heat-induction, and sand-packing and hot-slab forming. Ram pipe bending was probably the first pipe bending method used to cold-form materials.
This pipe bending method pushes a die against the tube or pipe by a mechanical force, forcing the pipe to conform to the contours of the die. Lacking internal support in the pipe, this pipe bending process creates some cross section ovality. The thinner the wall the more deformation of the pipe is seen.
Maximum pipe bending angle is normally 90 degrees. This is a commonly used pipe bending process where high levels of cross section ovality are acceptable such as furniture tubing, conduit and handrails.
During roll pipe bending, a series of spool-like rollers apply pressure to the pipe as it passes through them. Pipe bending operators change the location of the rollers to produce pipe of the desired radius. This pipe bending process is ideal for forming helical pipe coils for heat transfer applications as well as long sweeping sections such as those used in steel construction-curved trusses and roof components for structures requiring large open spaces. It deforms the pipe cross section very little for such sweeping sections.
The specialization of the company is providing tube manipulation services to clients. There is a range of specialist tube bending and forming services for compressor tubing, square or round tubing and mild steel, stainless steel or aluminium tubing.

The tube bending machines cater for round tubing from 6mm to 60mm with a maximum of 4mm wall thickness and square tubes up to 50mm with a 3mm wall thickness. The machinery works with ferrous and non-ferrous materials particularly mild steel, stainless steel and aluminium.

Square or round tubing can be supplied self coloured or finished, wet or powdercoated painted tubes, or they can be zinc plated for a clear or yellow finish. The company services a wide and diverse range of markets like the pneumatic and compressor markets, automotive, industrial, laboratory, aerospace and retail markets.
The benefit of using square tube bending versus round tubing is that you can attach braces and covering material to it so easily.
Then you can manufacture the rack for the four wheeler or tractor all by yourself to haul that old ice chest that no one makes a carrier that will fit it.
You could manufacture the rack to hold the garbage cans up high enough so that the dogs don't scatter it all over the street. You could make that bracket to hold some of that stuff on the floor of the garage up on the wall. That way you'd have room for more stuff on the floor of the garage.
A neat project would be to make a green house without one weld. It can be done.
The bender can be made without a welder. It can be used to fabricate all kinds of neat things and all without a welder.

BENDING MACHINES AND ANGLE ROLLS

Bending machine is versatile, it is easy to operate and is well suited for bending pipe, tube, aluminum extrusions and other sections.

Standard features include double pinch hydraulic forming rolls, hardened precision threaded shafts, and dual adjustable lateral guides.

The design is the result of years of experience and is aimed at providing the highest level of performance, accuracy and consistency throughout the life of the bending machine with the additional advantage of being virtually maintenance free.

The lateral guide rolls are hydraulically powered and can be adjusted to work very closely to the bending rolls, minimizing the distortion of non-symmetrical profiles. Moreover, the guide rolls are equipped with the tooling to bend angle leg-in.

Angle rolls machines are used for bending tube, angle, or shapes into coils, circles or large arcs using a wide variety of materials. By simply adjusting the third roll you change the size of the arc or circle. Tube bending sizes require specific rolls. There are rolls for any application including CNC bender controlled.

Profile rolls often called angle rolls. We used the same technology as our 3 and 4 roll plate bending rolls which results in a stronger and higher quality machine than most other manufacturers but still at a very competitive price.

The rolls can bend almost every profile and section in steel, stainless and aluminum and are virtually maintenance-free.

The components are:

• Heavy steel manufactured frame, machined on CNC machining centers for the best accuracy
• 3 direct driven rolls, with hydraulic planetary motor to eliminate gear boxes, connecting arms synchro devices and clutches
• 2 forming rolls for reduction of flat ends
• double roll spherical bearings SFK or equal = maintenance-free and maximum rigidity
• hydraulic motors attached directly to each planetary drive, eliminating the loss of torque
• Modular tooling which can be configured to roll most standard sections. Special tooling can be ordered for rolling pipe, tubing or channels the hard way.