There are numerous ways of laying-out boxes and numerous ways of folding them up. The MAGNABEND is ideally suited to forming boxes, especially complex ones, because of the versatility of using short clampbars to form folds relatively unhindered by previous folds.
For bends up to 70 mm long, just select the largest clamp piece that will fit.
For longer lengths it may be necessary to use several clamp pieces. Just select the longest clampbar that will fit in, then the longest that will fit in the remaining gap, and possibly a third one, thus making up the required length.
For repetitive bending the clamp pieces may be plugged together to make a single unit with the required length. Alternatively, if the boxes have shallow sides and you have available a slotted clampbar, then it may be quicker to make the boxes in the same manner as shallow trays.
Lipped boxesLipped boxes can be made using the standard set of short clampbars provided one of the dimensions is greater than the width of the clampbar (98 mm).
1. Using the full-length clampbar, form the length wise folds 1, 2, 3, &4.
2. Select a short clampbar (or possibly two or three plugged together) with a length at least a lip-width shorter than the width of the box (so that it may later be removed). Form folds 5, 6, 7 & 8.
While forming the folds 6 & 7, be careful to guide the corner tabs either inside or outside the sides of the box, as desired.
Boxes with separate endsA box made with separate ends has several advantages:
- it saves material especially if the box has deep sides,
- it does not require corner notching,
- all cutting-out can be done with a guillotine,
- all folding can be done with a plain full-length clampbar;
and some drawbacks:
- more folds must be formed,
- more corners must be joined, and
- more metal edges and fasteners show on the finished box.
Making this kind of box is straight forward and the full-length clampbar can be used for all folds.
Flanged boxes with plain cornersPlain cornered boxes with outside flanges are easy to make if the length and width are greater than the clampbar width of 98 mm.
Forming boxes with outside flanges is related to making TOP-HAT SECTIONS (described in a later section)
Flanged Box with Corner TabsWhen making an outside flanged box with corner tabs and without using separate end pieces, it is important to form the folds in the correct sequence.
FORMING TRAYS USING THE SLOTTED CLAMPBARThe Slotted Clampbar, when supplied, is ideal for making shallow trays and pans quickly and accurately.
The advantages of the slotted clampbar over the set of short clampbars for making trays are that the bending edge is automatically aligned to the rest of the machine, and the clampbar automatically lifts to facilitate the insertion or removal of the workpiece. Never-the-less, the short clampbars can be used to form trays of unlimited depth, and of course, are better for making complex shapes.
In use, the slots are equivalent to gaps left between the fingers of a conventional box & pan folding machine. The width of the slots is such that any two slots will fit trays over a size range of 10 mm, and the number and locations of the slots are such that for all sizes of tray, there can always be found two slots that will fit it. (The shortest and longest tray sizes the slotted clampbar will accommodate are listed under SPECIFICATIONS.)
To fold up a shallow tray:
Top-Hat ProfilesThe Top-Hat profile is so-named because its shape resembles a top-hat of the kind that was worn by English gentlemen in past centuries:
Top-hat profiles have numerous uses; common ones being stiffening ribs, roof purlins and fence posts.
Top-hats can have square sides, as shown below on the left, or tapered sides as shown on the right:
A square-sided top hat is easy to make on a Magnabend provided that the width is more than the width of the clampbar (98mm for the standard clampbar or 50mm for the (optional) narrow clampbar).
A top hat with tapered sides can be made much narrower and in fact its width is not determined by the width of the clampbar at all.
An advantage of tapered top-hats is that they can be lapped over each other and joined to make longer sections.
Also, this style of top-hat can nest together thus making a very compact bundle to facilitate transport.
How to make top-hats:
Square-sided top-hats can be made as shown below:
When using these techniques the machine will not have its full bending thickness capacity and thus sheetmetal up to about 1mm thick only can be used.
Also, when using a square bar as auxiliary tooling it will not be possible to overbend the sheetmetal to allow for springback and thus some compromise may be necessary.
Tapered top-hats:If the top hat can be tapered then it can be formed without any special tooling and the thickness can be up to the full capacity of the machine (1.6mm for top-hats over 30mm deep or 1.2mm for top-hats between 15mm and 30mm deep).
The amount of taper needed depends on the width of the top-hat. Wider top-hats can have steeper sides as shown below.
For a symetrical top-hat all 4 bends should be made to the same angle.