User Manual for Models 650E, 1000E, and 1250E

MODEL                                                   SERIAL NO.                                          DATE

EARTHING CONNECTIONS

Measure resistance from mains plug earth pin to magnet body .... ohm

ELECTRICAL ISOLATION

Megger from coil to magnet body

MIN/MAX SUPPLY VOLTAGE TESTS

At 260v: Pre-clamp.... full-clamp.... release

At 200v: Pre-clamp.... release

Pre-clamp.... full-clamp.... release

INTERLOCK SEQUENCE

With power on, pull HANDLE, then press START button.

Check that machine does NOT activate

TURN-ON/OFF ANGLES

Movement of Bending Beam to activate full-clamping,

measured at bottom of bending beam. (4 mm to 6 mm)  mm

Reverse motion to switch-off machine. Measure back

from 90°. (Should be within the range 15° + 5° )  deg

ANGLE SCALE

Reading at edge of Indicator when bending beam is set

to 90° with an engineer's square. (min 89° , max 91° )  deg

MAGNET BODY

Straightness of top surface, along front pole

(max deviation = 0.5 mm)  I mm

Flatness of top surface, across the poles

(max deviation = 0.1 mm)   mm

BENDING BEAM

Straightness of working surface (max deviation =0.25 mm)

Alignment of extension bar (max deviation = 0.25 mm)  [Note: Test straightness with precision straight-edge.]

MAIN CLAMPBAR

Straightness of bending-edge (max deviation = 0.25 mm)  Height of lift (with lifting balls in grooves) (min 3 mm)  Can lifting balls be compressed flush with surface  With adjusters set at ⁿ 1ⁿ and the bending beam at 90°

is the bending-edge parallel to, and I mm from, the beam  With the bending beam at 90°, can the clampbar be adjusted forward to touch and rearward by 2 mm

HINGES

Check for lubrication on shafts .  and sector blocks

Check that hinges rotate through 180° freely and smoothly

Check hinge pins do not rotate. and are loctited

Have the retaining screw nuts been locked?

BENDING TEST

(A maximum specification bend to 90°, at minimum supply voltage.)

Steel test piece thickness

Width of lip

mm, Bend length

mm, Bend radius

Uniformity of bend angle (maximum deviation = 2°)

LABELS

Check for clarity, adhesion to machine and proper alignment.

Nameplate & Serial No

Electrical warnings

Clampbar Warning

Switch labelling

Safety tape on front legs  

FINISH

Check cleanliness, freedom from rust, blemishes etc

SIGNATURES

Assembled & Tested .

Q. A. Inspection

BASIC OPERATION

WARNING

The Jdc bend sheet metal folder can exert a total clamping force of several tonnes (see SPECIFICATIONS). It is equipped with a two-handed interlock to help ensure that fingers cannot be inadvertently caught under the clampbar when electro-magnetic clamping is applied.

However, it is most important that only one operator use the machine at a time. It is potentially dangerous for one person to insert the work piece and handle the clampbars while another person operates the switches !

NORMAL BENDING

Ensure power is ON at the power outlet and the full-length clampbar is positioned on the machine with its lifting balls resting in the locating grooves at each end.

1.Adjust for workpiece thickness by rotating the eccentric adjusters at either end of the clampbar. Lift the bending beam up to the 90° position and check that it is parallel to the edge of the clampbar - if necessary readjust the eccentric lifters.
(For optimum results the gap between the clampbar edge and the surface of the bending beam should be set to slightly greater than the metal thickness to be bent.)

2.Insert the workpiece then tilt the front edge of the clampbar down and align the bend line to the bending edge.
3.Press and hold the START button. This applies pre-clamping.

4.With the other hand pull on the handle. Full clamping is now automatically applied and the START button should now be released. Continue bending until the required angle is reached.
5.The bending beam may be reversed about 10° to 15° to take pressure off the workpiece for checking the bend angle. Reversing by more than 15° automatically turns the machine off and releases the work piece.
CAUTION

• To avoid the risk of damaging the bending edge of the clampbar or of denting the top surface of the magnet body, do not put small objects under the clampbar. The recommended minimum bend length using the standard clampbar is 15 mm, except when the work piece is very thin or soft.
• The clamping force of the magnet is less when it is hot. Therefore to get the best performance apply clamping for no longer than is necessary to do the bend.

POWER SHEAR (Optional accessory)

INSTRUCTIONS FOR USE

The power shear (based on the Makita Model JS 1660) provides a means for cutting sheetmetal in such a way that very little distortion is left in the workpiece. This is possible because the shear removes a waste strip, about 4 mm wide, and most of the distortion inherent in shearing sheetmetal goes into this waste strip. For use with a Jdcbend the shear has been fitted with a special magnetic guide.

The shear works well in combination with a Jdcbend Sheetmetal Folder; the Jdcbend provides both a means of holding the workpiece fixed while being cut and also a means for guiding the tool so that very straight cutting is possible. Cuts of any length can be handled in steel up to 1.6 mm thick or aluminium up to 2 mm thick.

To use the tool first place the sheetmetal workpiece under the clampbar of the Jdcbend and position it so that the cutting line is exactly ] mm in front of the edge of the Bending Beam.

A toggle switch labelled "NORMAL / AUX CLAMP,, will be found next to the main ON/OFF switch. Switch this to the AUX CLAMP position to hold the workpiece firmly in position.

Position the shear at the right-hand end of the Jdcbend and ensure that the magnetic guide attachment engages on the front edge of the Bending Beam. Start the power shear and then push it evenly along until the cut is completed.

Notes:

1. For optimum performance the blade clearance should be adjusted to suit the thickness of material to be cut. Please read the Makita instructions supplied with the JS1660 shear.
2. If the Shear does not cut freely check that the blades are sharp.

FOLDED LIP

FOLDING A LIP (HEM)

The technique used for folding lips depends on the workpiece thickness and to some extent, on its length and breadth.

Thin Workpieces (up to 0.8 mm)

1.Proceed as for normal bending but continue the bend as far as possible (135°).
2.Remove the clampbar and leave the workpiece on the machine but move it rearwards about 10 mm. Now swing the bending beam over to compress the lip. (Clamping need not be applied). [Note: Do not attempt to form narrow lips on thick workpieces].

3.With thin workpieces, and/or where the lip is not too narrow, a more complete flattening can be achieved by following with magnetic clamping only:

ROLLED EDGE

FORMING A ROLLED EDGE

Rolled edges are formed by wrapping the workpiece around a round steel bar or piece of thick-walled pipe.

1.Position the workpiece, clampbar and rolling bar as shown.
a) Ensure that the clampbar does not overlap the front pole of the machine at "a" as this would allow magnetic flux to bypass the rolling bar and hence clamping would be very weak.

b) Make sure the rolling bar is resting on the steel front pole of the machine (“b") and not further back on the aluminium part of the surface.

c) The purpose of the clanipbar is to provide a magnetic pathway ("c”) into the rolling bar.

2.Wrap the workpiece as far as possible then re-position as shown.

 

3.Repeat step 2 as required.

TEST PIECE

INSTRUCTIONS FOR FORMING TEST PIECE

In order to gain familiarity with your machine and the type of operations that can be performed with it, it is recommended that a test-piece be formed as described below:

1.Select a piece of 0.8 mm thick mild steel or aluminium sheet and cut it to 335 x 200 mm.
2.Mark lines on the sheet as shown below:

3.Align Bend 1 and form a lip on the edge of the workpiece. (See

”FOLDED LIP”)

4.Turn the test piece over and slide it under the clampbar, leaving the folded edge towards you. Tilt the clampbar forward and line up Bend 2. Make this bend to 90°. The test piece should now look like this:

…TEST PIECE

5.Turn test piece over and make Bend 3, Bend 4 and Bend 5 each to 90°
6.To complete the shape, the remaining piece is to be rolled around a 25 mm diameter round bar of steel.

• Select the 280 mm clamp-bar and place it, the test piece and the round bar on the machine as shown under "ROLLED EDGE" earlier in this manual.
• Hold the round bar in position with the right hand and apply preclamping by pressing and holding the START button with the left hand. Now use your right hand to pull the handle as if doing an ordinary bend (the START button may be released). Wrap the workpiece as far as possible (about 90°). Reposition the workpiece (as shown under "Forming a Rolled Edge") and wrap again. Continue until the roll is closed.

The test shape is now complete.

BOXES ...

MAKING BOXES (USING SHORT CLAMPBARS)

There are numerous ways of laying-out boxes and numerous ways of folding them up. The JDCBEND 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.

Plain Boxes

1.Make the first two bends using the long clampbar as for normal bending.
2.Select one or more of the shorter clampbars and position as shown. (It is not necessary to make up the exact length as the bend will carry over gaps of at least 20 mm between the clampbars.)

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. (See next section: TRAYS)

Lipped boxes

Lipped 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 ...

Boxes with separate ends

A box made with separate ends has several advantages:

-it saves material 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.

1.Prepare the blanks as shown below.
2.First form the four folds in the main workpiece.

3.Next, form the 4 flanges on each end piece. For each of these folds, insert the narrow flange of the end piece under the clampbar.
4.Join the box together.

 

Flanged boxes with plain corners

Plain 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 - see Contents).

4.Prepare the blank.
5.Using the full-length clampbar, form folds 1, 2, 3 & 4.
6.Insert the flange under the clampbar to form fold 5, and then fold 6.
7.Using appropriate short clampbars, complete folds 7 & 8.

... BOXES

Flanged Box with Corner Tabs

When 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.

1.Prepare the blank with corner tabs arranged as shown.

2.At one end of the full-length clamp bar, form all tab folds "A" to 90. It is best to do this by inserting the tab under the clampbar.
3.At the same end of the full-length clampbar, form folds ⁿBⁿ to 45° only. Do this by inserting the side of the box, rather than the bottom of the box, under the clampbar.
4.At the other end of the full-length clampbar, form the flange folds "C" to 90°.
5.Using appropriate short clampbars, complete folds ⁿBⁿ to 90.
6.Join the corners.
Remember that for deep boxes it may be better to make the box with separate end pieces.

SLOTTED CLAMPBAR

FORMING TRAYS (USING SLOTTED CLAMPBAR)

The 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:

1. Fold-up the first two opposite sides and the corner tabs using the slotted clampbar but ignoring the presence of the slots. These slots will not have any discernible effect on the finished folds.
2. Now select two slots between which to fold-up the remaining two sides. This is actually very easy and surprisingly quick. Just line-up the left side of the partly made tray with the leftmost slot and see if there is a slot for the right side to push into; if not, slide the tray along till the left side is at the next slot and try again. Typically, it takes about 4 such tries to find two suitable slots.
3. Finally, with the edge of the tray under the clampbar and between the two chosen slots, fold up the remaining sides. The previously formed sides go into the selected slots as the final folds are completed.

With tray lengths that are nearly as long as the clampbar it may be necessary to use one end of the clampbar in lieu of a slot.

BACKSTOPS

USING THE BACKSTOPS

The backstops are useful when a large number of bends have to be made all of which are the same distance from the edge of the workpiece. Once the backstops are correctly set any number of bends can be made without the need for any measuring or marking out on the workpiece.

Normally the backstops would be used with a bar laid against them so as to form a long surface on which to reference the edge of the workpiece. No special bar is supplied but the extension piece from the bending beam may be used if another suitable bar is not available.

NOTE: If it is required to set a backstop under the clampbar, then this can be done by using a strip of sheetmetal the same thickness as the workpiece, in conjunction with the backstops.

ACCURACY

CHECKING THE ACCURACY OF YOUR MACHINE

All functional surfaces of the Jdcbend are manufactured to be straight and flat to within 0.2 mm over the entire length of the machine.

The most critical aspects are:

1. the straightness of the working surface of the bending beam,
2. the straightness of the bending edge of the clamp bar, and
3. the parallelism of these two surfaces.

These surfaces can be checked with a precision straight-edge but another good method of checking is to reference the surfaces to each other. To do this:

1. Swing the bending beam up to the 90° position and hold it there. (The beam can be locked in this position by placing a back-stop clamp collar behind the angle slide on the handle).
2. Observe the gap between the bending edge of the clamp bar and the working surface of the bending beam. Using the clamp bar adjusters set this gap to 1 mm at each end (use a scrap piece of sheet metal, or a feeler gauge).

Check that the gap is the same all the way along the clampbar. Any variations should be within ±0.2 mm. Tliat is the gap should not exceed 1.2 mm and should not be less than 0.8 mm. (If the adjustors do not read the same at each end then reset them as described under MAINTENANCE).

Notes:

1. The straightness of the clampbar as observed in elevation (from the front) is not important as this gets flattened out by magnetic clamping as soon as the machine is activated.
2. The gap between the bending beam and the magnet body (as observed in plan-view with the bending beam in its home position) is normally about 2 to 3 mm. This gap is not a functional aspect of the machine and does not affect the bending accuracy.
3. The Jdcbend can produce sharp folds in thinner gauges and in nonferrous materials such as aluminium and copper. However in thicker gauges of steel and stainless steel do not expect to achieve a sharp fold (see specifications).
4. Uniformity of the bend in thicker gauges can be enhanced by using scrap pieces of the workpiece to fill in the unused portions under the clampbar.

MAINTENANCE

WORKING SURFACES

If the bare working surfaces of the machine become rusty, tarnished or damaged, they may be readily reconditioned. Any raised burrs should be filed off flush, and the surfaces rubbed with P200 emery paper. Finally apply a spray- on anti-rust such as CRC 5.56 or RP7.

HINGE LUBRICATION

If the Jdcbend sheetmetal folder is in constant use, then grease or oil the hinges once per month. If the machine is used less, then it may be lubricated less frequently.

Lubrication holes are provided in the two lugs of the main hinge plate, and the spherical bearing surface of the sector block should also have lubricant applied to it.

ADJUSTERS

The adjusters at the ends of the main clampbar are to control the allowance for the thickness of the workpiece between the bending-edge and the bending beam. The adjusters are factory-set to give a thickness allowance of 1 mm when the adjuster indicators "1”. To reset this, proceed as follows:

1.Hold the bending beam at 90.

2.Insert a small piece of 1 mm sheetmetal at each end between the bendingedge and the bending beam.
3.Ignoring the indicating marks, adjust the adjusters until the 1 mm pieces are just lightly "nipped" between the bending-edge and the bending beam.
4.Using a 3 mm Allen key, carefully loosen the grub-screw to free the knurled ring of one of the adjusters. Then rotate the ring till the indicating slit indicates "1 ⁿ. Do this without rotating the inner body of the adjuster. Then re-tighten the grub-screw.
5.Reset the other adjuster in the same manner.
The spring-loaded lifting balls in the underside of the adjusters may stick if dirt or rust-forming moisture gets in. If this happens, remedy it by pressing the ball in and out with a blunt tool while spraying in a penetrating lubricant such as CRC 5.56 or RP7.