Productos De Los Cursos Basicos De Formacion 2011

MODEL 3 TUBE BENDER

Assembly & Operating Instructions

Online Ordering Available Through Medford Tools and Supply Inc

1-800-841-1133

Page 2

Die Set Components

A Die Set refers to the components that are used in the bender to hold the tubing or pipe during the bending operation. This

section does not describe the operation of the bender. This section's purpose is to simply familiarize you with the different

components that make up a 'Die Set'. Knowing how the different die set parts interact with each other is essential in operating

the bender correctly. The die set must match the size of the tubing or pipe being bent. For example, never bend 1 1/2" tubing in

a 1 5/8" die set. This may damage the followbar's inserts.

First, let's explain the difference between tubing and pipe. Tubing is specified by its outside diameter and a wall thickness.

For example, 1 1/2" x .095" tubing has an outside diameter of 1 1/2" and a wall thickness of .095". On the other hand, pipe is

specified loosely on its inside diameter. We say loosely because the pipe's size may not actually be its inside diameter. Confused

yet? Just remember pipe is commonly used for the purpose of transporting fluids. Fluid flow is only concerned with the inside

area of the pipe and the outside makes no difference what so ever. Pipe wall thickness is specified as a schedule number and

is obtained from a pipe chart. Another example, 1 1/2" schedule 40 pipe has an outside diameter of 1.900" (larger than 1 7/8")

and a wall thickness of .145" and an inside diameter of 1.610" (near 1 5/8"). So, when ordering die sets be careful to specify whether

it's a tube or pipe size die set.

ROUND GROOVE DIES:

A Round groove die set consists of three main elements:

1) Forming Die

This is the part that the tube or pipe actually bends around. It has a circular groove machined around its circumference.

Please note that this groove is machined with a specially designed profile to help in reducing flattening of the bend's outside.

If you lay a section of tubing into the forming die you will notice that it will NOT completely seat into the die's groove. This is

normal for tube size dies and becomes very important as the tube's wall thickness gets thinner. However, forming dies that

are machined for 'Pipe' instead of tubing are generally not manufactured with this profile and the pipe may completely seat

in the groove. Pipe is much more forgiving when it comes to bending it because of its thicker wall. Stamped into the top is

the Outside diameter of the tube or pipe and the centerline radius (CLR) of the forming die. Above is pictured a 3/4" die with

a 2 1/4" CLR and a 1 1/2" die with a 4 1/2" CLR.

Drive holes are drilled into most dies with a radius of 3" or larger. When the 7/8" drive pin is inserted into the drive links,

it will pass through these holes. This is how the drive links rotate the forming die. The 1" drive holes are drilled oversize to

permit easy insertion of the 7/8" drive pin.

Die sets with a radius smaller than 3" will generally not have drive holes because there is no room to drill them. As

explained in the following section on how to operate the bender, the diameter of the tubing or pipe is so small the bender

can be operated without the use of the ratchet mechanism.

2) U-Strap

U-straps are sized to the OD of the pipe or tubing being bent. The

size is stamped onto them.

3) Followbar (Also referred to as the Pressure Die)

The Followbar is the component that presses the tubing into the forming die to create the bend. Shown in the illustration below, it consists of three main parts: a backing block, an angled rear insert and a straight 0 degree front insert. This multipart design allows the inserts, if damaged or worn out, to be inexpensively replaced without having to purchase a whole followbar assembly. The Inserts are permanent cast from a special bearing grade anti-galling material to protect the tubing from scratching during the bending process and then CNC machined to size. They are silverish in color but are NOT aluminum.

REPLACING INSERTS

The

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