Mini Press-brake project
I needed to be able to bend metal for a project at 90 degrees and with varying thicknesses up to around 3mm with lengths up to 350mm, a professional press-brake was simply out of the question and some of the home-builds on youtube which were made of bits of angle-iron did not look too useful. I had a 20t hydraulic press that had a column width of 450mm so making a tool to fit this seemed ideal.
After some research I found tooling for professional machines was available on eBay and also in short lengths that would fit nicely in my press. A dual channel bottom die was bought with V widths of 12mm and 22mm this would allow a good range of thicknesses to be folded withing my range, this was limited by the 20t of pressure I had available in the press.
For the top tool I chose a swan-neck design as they allow U-shaped folds to be made easily, both tools were for the common Euro style or Adama press-brake machines, these were the cheapest.
A simple frame was built from some 4″ x 3/4″ steel plate, this was used as the base plate and the beam support for the top tool. Upright columns were 1″ steel rounds about 300mm long. The base was made to just fit between the columns of my press, the tooling was 415mm long.
The tool support beam for my mini press-brake was mounted on the guide columns by boring out some larger diameter rod and welding it on to the ends of the beam. A step was milled into the bottom face of the beam to allow the tooling to sit as it would on a real machine. Four clamps were milled from square section steel to hold the top tool using its correct mounting channel, these can be seen in the photo’s, they are mounted on some 10mm studs with nuts and washers.
Two compression springs were fitted to lift the top tool clear of the die as the pressure was released, these springs were guided by some turned nylon collars which not only made the action very smooth but gave a needed 1″ lift to the height. By keeping the line of force from the tip of the tooling back to the ram of the press in line with the centers of the two vertical guide rods, any tendency to twist is removed and all the applied pressure is seen as force at the tip of the tool – just where it’s needed.
The bottom die is held by some small blocks tack-welded in place, this die is reversible to allow both channels to be used depending on width needed – thicker materials need a wider channel when bending in a press-brake.
Nylon caps were fitted onto the tops of the guide rods, secured with a socket head screw to enable the press-brake assembly to be lifted without it falling apart – it’s very heavy.
Tests bends were done on some scrap and it worked perfectly, tonnage required followed the available charts very closely, a full width 410mm bend in 3mm steel needs around 18 tons of pressure, all in all, a very enjoyable build and a useful workshop accessory too.