Thursday, October 23rd, 2014
The manufacturing processes we go through to produce sheet metal work illustrated by a batch of 4mm thick 304 stainless steel brackets
Most sheet metal components that we manufacture here at V and F Sheet Metal start with us creating a 3D software model, the only exception being flat panels. The 3D model enables us to test out any hole alignment issues that might occur when assembling several parts together such as lids fitting on housings or front panels lining up with enclosures. We can use the 3D model to create a flat developed blank with the correct cut size calculated for any given material type and thickness. The 3D model also has the advantage of enabling us to show our customers any problems that we think may occur in manufacturing their sheet metal components before we have to start CNC punching or laser cutting any sheet metal. It also allows us to give some customers their first view of their part in 3D if they only use 2D CAD software. We are lucky and have some customers who also use 3D software and can output either SAT or STEP files which we can then read straight into our Radan CAD/CAM software speeding up the whole process of CNC program generation. The next stage after generating a 3D model is to create the CNC tooled part and then the part nest.
A single sheet metal part is taken from the 3D model as a flat blank which is then refined and cleaned up to produce the profile needed for the customer. This part is easily tooled up for laser cutting with all the cutting lead ins and profile allowances calculated by the software. Then, as with CNC punching we can use the software to calculate the most economical fit of components for any given sheet size. The software will also automatically find the quickest path to cut all the parts on the sheet so that the laser head doesn’t travel over any areas that have already been cut, reducing the risk of head collisions with sheet metal that might be protruding from the surface of the parent sheet and keeping heat build up to a minimum within the sheet.
This image perfectly illustrates the Trumpf laser cutter controller with the job cutting in progress. The green parts on the screen have been laser cut and the grey are still to be cut, so at this stage 10 and a half parts have been laser cut. The path will follow exactly that which has been laid down by the Radan CAD/CAM software and output in the compiled laser block file. The operator has control over the speed of the cut, gas flows, nozzle size and focus but cannot change any design details of the components being cut. You can just see inside the laser cutter (on the left hand side) through the filter glass, the operator has a view of the machine while it’s cutting being able to monitor cutting progress and act on any error messages that may arise on the control at the same time.
Here’s a view inside the Trumpf 3030 fibre laser machine as it’s cutting the 4mm thick stainless steel sheet. You get a good idea how close to the edge of the sheet we can program parts and laser cut them enabling us to use as much material as possible keeping the component part prices down for our customers. The image has a yellow/green look as it’s taken through a special filtered glass door which is essential on fibre laser machines to filter out certain light wave lengths given off by the fibre laser that could be harmful to the naked eye. The operator can stop the machine at any time open the safety doors, reach inside and remove a part to check the edge quality, change a parameter if needed and then safely resume cutting from the same point without wasting any material or potential finished components from a sheet. If more than one sheet is required to satisfy the order volume the Trumpf 3030 3KW fibre laser cutter has a pallet changer that allows a cut sheet to be swapped with a fresh sheet of metal automatically to keep the laser cutter working while cut parts can be removed and another fresh sheet loaded on the pallet changer.
Fast Tube by Casper
And here’s the Trumpf 3030 3KW fibre laser in action cutting straight through the 4mm thick stainless steel plate. The laser cut edge quality means that no other de-burring was needed on these parts.
Fast Tube by Casper
One of our Edwards Pearson CNC press brakes being used to fold up the stainless steel blanks into brackets.
And finally the stainless steel brackets being folded up. It’s not that easy to see here but the tooling we use on this machine enables us to fold more than just 90 deg bends, this type of V tooling is called air bend tooling. We can fold up angles from just a fraction of a degree to approx 30 deg inclusive angle, if we need to fold a component right over into a dutch fold (safe edge) we apply a second bending operation to flatten down the V bend. The back stops behind the CNC press brake tooling can move from side to side and in and out towards the tooling. This enables us to program in different bend lengths, bend angles and a range of bends on the same part along the full bed of the machine if necessary so that a completed component can be produced in one series of bends rather than having to set the CNC press brake several times for each bend type. This enables us to produce the first finished component much faster for inspection and on a large batch of parts we can part batch if needed to get an urgent job started for our customers.
The final bracket has been processed through the CAD/CAM software from a 3D model, laser cut and CNC bent all within our production factory in Fareham, Hampshire. There were 2 slightly different brackets run together with slightly different angles but all the same manufacturing processes and materials, the flexibility of CNC laser cutting and CNC bending allows us to easily use these machines to make a range of parts with minimal set up times and fuss.
If you have a sheet metal project that needs laser cutting, CNC punching or CNC bending please let us take a look and see how we can help remove cost from your parts.