STRONGMAN METAL TOOLS

Use of the MB50R Multi Stopper

The Purpose of the Multi Stopper is to stop the rotation of the bending die (when bending 38 to

50mm tube) or bending arm (when bending solid bars or tube up to 32 mm) at the exact angle

required in order to make repeat bends to specific angles.

The Stopper consist of 3 parts

A Long Stopper Pin, a Base, and a Short Stopper Pin.

The Long Pin is used for bending with die sets of 38 to 50 mm while the Short Pin is used with

bending dies for 32 to 12 mm tube as well as for bending solid bar.

The base is positioned onto the Bender Degree Ring at the position of the angle where the bend

should stop, and then fastened in position. With the cap screws from the top and the washers and

wingnuts at the bottom.

Either the short or long stopper is then screwed onto the top of the base.

Additional stopper bases can be fastened onto the degree ring at different angles.

This makes it easy to pre-set many different bend points on the bender by installing the stopper

base at the required angle points for example, at the marks for making a 90° and 45° bend.

The Stopper Pin is then screwed into position on the base corresponding to the required angle.

This saves time by not having to remove and reinstall the base every time another angle is required.

USING THE MULTI STOPPER FOR BENDING 90° IN 50 MM TUBE.

The tube is loaded and fastened in the tube clamp. The bender arm is then rotated clockwise, by

hand, using force, until it stops moving. (1)

This is the full engaged point-The point where, if further pressure is applied to the Bend Arm it will

start to bend the tube.

TIP: Depending of the position of the tube when it was tightened in the clamp, the full engaged point

may differ from a previous full engaged point.

To overcome this, once the tube has been clamped and the arm moved clockwise to the full engaged

point. Reset the the arm by rotating it anti-clockwise, away from the full engaged point (2).

Then again rotating it clockwise to the full engaged point (3).

This reset will eliminate any discrepancies in the angle of the full engage point.

Using a square, the angle indicated by the indicator needle, attached to the die, is read off the

degree ring. In this case 75°.

To bend a 90° angle in 50x2 round tube the Multi Stopper should be set at 173°.

The 173° is calculated as follows:

Start angle of indicator, with bend arm in engaged position: 75°

Required Bend Angle: 90°

Over bend required to overcome spring back of tube once bending pressure is released: 8 °

Thus: 75+90+8=173°

75°

°

Indicator Needle

Bend Arm in rotated to engaged position

1 2

3

A square is used to align the outer edge of the stopper pin with the position corresponding to the

173° mark on the Degree Ring.

The bend arm is now rotated in a clockwise direction with the use of the Ratchet Arm to bend the

tube.

As the bend progress the die is rotated and the indicator needle is moving closer to the Stopper Pin.

173°

Stop bending when the Indicator Needle touches the Stopper Pin.

The Tube is now bent to 90° and can be released from the die.

USING THE MULTI STOPPER WHEN BENDING SOLID BARS OR 12 TO 32MM TUBE DIES.

In this example 2 off 10 mm square bars are bent.

Start by loading the material in the bender.

For bending solid bar and tube from 12 to 32 mm, the angle measure is taken from the Bend Arm.

Thus the Bend Arm will need to touch the Stopper Pin at the required angle.

In the picture below you will see that the material will reach the pin before the bend arm does.

Why is the Bend Arm used to measure the angle and not the material?

Note that the axis of the material is not aligned with the Pivot Pin at the center of the Bender Base,

and Degree Ring. An accurate angle measure can only be made by using the start and end positions

of the bender arm, as its axis is aligned with the pivot pin.

To enable the material to move over the stopper pin so that the bend arm can touch the pin we will

need to replace the long stopper pin with the shorter pin.

The material will now fly over the Stopper Pin.

The Bend Arm will touch the pin when the set angle is reached. The bend is now complete.