SQUARE AND ROUND TUBE BENDER
The Multi Tube bender is supplied with four formers which can be used for either square or round tube in a large variety of sizes. The formers are machined to suit 13mm (½ ), 15mm (5/8" using shim spacer washer provided), 19mm (¾ ") 20mm with spacer again and 25mm (1"). Maximum capacity is 25mm x 1.6mm tube, however by cutting shim spacing washers out of the appropriate gauge sheet metal or aluminium plate, other sizes can easily be bent using the same formers. Two washers of the same thickness should always be used on either side of the former. This ensures that the former is kept central on the tube.
The Bender can be mounted either in a sturdy vice attached to a heavy or fixed bench or it may be bolted onto a solid post, column or even vehicle bull bar through the two bolt holes in the angle mounting plate. (½ " high tensile bolts must be used)
Before bending a new size or gauge of tube it is recommended that a test bend be done to ascertain the amount of compression onto the former which may affect the final dimension of the article being produced. As a general rule the distance between the centre of the bend marks, becomes the inside dimension after bending.
Determine the centre of a bend is done using a short piece of tube (say 400mm) marked exactly halfway along itís length. This piece is clamped into the bender at an approximate position and a pencil mark made in line with the centre mark. After bending, measure the difference between the length of each side of the bend. The line on the bender plate is then moved half that difference, which should now be the correct centre mark for that size tube (when bending 90º ).
The top plate on the former is shaped to allow it to be used on all tube sizes. To bend tube using the largest former, the plate must be clamped with the cut away section on the left hand size. It can then be rotated to the top position where marking out lines are able to be seen when using the smaller formers.
Always clamp the tube firmly before bending or else it will tend to slip through the former and collapse the bend.
The adjustable stopper can be used to repeat bends on the same angle. When setting the stopper there has to be an allowance made for the amount the tube will spring back when the handle is released.
When bending lighter gauge round tube it may be best to place a piece of 25mm a 6mm or similar flat bar between the roller and the tube to prevent the roller forming a flat on the tube.