For EMF camp 2024 I'm making an electrically driven, tracked tricycle (it's probably not a tricycle, if you count the tracks wheels it has 7, but a septacycle doesn't sound right...).
As part of this build I need a few parts in 4mm plate steel that have well aligned bends. I've been using the sheet metal system of Fusion 360 to design these, and it's 'unfold' function to give me a 2D drawing of the cut out lines of the part.
I added a line along the centre of the fold to this. I'll create a groove along this line to locate on the bend knife of my bending machine and will create the groove using a none piercing cut on my plasma cutter.
The groove was created with about 50% of the power of a piercing cut using my ArcDroid CNC plasma,
And then the part was cut out with a piercing cut.
I then aligned this groove onto the bending machine and started the bend.
It came out well. I'll weld over the groove to make sure it's not weak.
The larger plate is more problematic. It has two bends in opposite directions. I can only create the grooves on the 'cut' side of the plate. The second groove will be facing downwards and won't be able to engage with the bend knife.
I used the technique above to create the grooves and cut out the part.
To solve this I designed a 3D printed alignment block. It has a triangular form to centre it it the V groove of the bender (and align it directly above the bending knife) and a sharp ridge on top to locate in the groove of the workpiece,
With two of these in place, it's easy to align the groove with the ridge.
And the guides are destroyed in the process. They only take 10 minutes to print two though.
The opposite bend blew out the plate slightly but I'll just reinforce this with the welder.
Overall though, I'm very pleased with the end result and would certainly use this technique again.
Here's the video of the process:
