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Sheet metal cnc punching

Thursday, May 21st, 2015

CNC punched ventilation grilles

CNC punched ventilation grilles

These heater ventilation grilles have been CNC punched out with specially ground punch and die tooling to speed up production and produce a shape that when bent up produces very little resistance to air flow thereby increasing the overall efficiency of the heater. The parts were CNC punched on our trusty Trumpf 200 punch press which has produced 10s thousands of these parts over the years with no problems at all. The Trumpf 200 machine is a flexible production tool that seems to be able to turn it’s hand to almost anything we through at it and just keeps going and going. With regular services the machine can still produce parts to +/- 0.1mm accuracy and clean edges.

CNC punching electronics chassis covers

CNC punching electronics chassis covers

Here we have a batch of mild steel audio equipment chassis covers that have just been CNC punched on our main CNC punch press the Trumpf 3000R. The ventilation slots have been produced by using a standard library obround punch and die tool set and we have used the presser foot feature on the Trumpf 3000 to stop the webs between the slots tripping up in the sheet. This feature is controlled by the program software to enable us to press the head onto the sheet for the hits that we want. With common line cutting between the panels using a 70 x 5 rectangle tool there is very little waste sheet and the time is also reduces to produce each part leading to competitive prices for the customer.

CNC punched ventilation pattern

CNC punched ventilation pattern

CNC punching a pattern of holes that are close together can often create a lot of stress within the sheet metal. With our Trumpf 3000 we can program the machine’s punching head to press down on the sheet with each hit helping to hold the sheet in place, reducing the amount of distortion. This product is still in the prototype stages but we are expecting to make quite a few of them over the next few months.

If you have a sheet metal project that needs CNC punching, please give us a call and we will be happy to take a look and see what we can do to give you a competitive price or review your design to save money in manufacturing.


Zintec sheet metal components

Monday, May 18th, 2015

Zintec sheet metal components

Zintec sheet metal components

Another day at V and F and these zintec base plates caught my eye and a good example of various production methods working together.

Zintec is a zinc coated mild steel sheet metal that can be used as a good pre-treated surface for components that are going to be painted or powder coated. Zintec can also be used on it’s own in some cases where sheet metal components are kept dry and require minimal corrosion protection. In this case these base plates or a piece of scientific equipment have been manufactured by laser cutting, CNC bending and then having a range of sheet metal bushes and studs inserted using our Haeger inserter and will be powder coated. All the laser cut edges are perfectly clean as they were cut using nitrogen for a burn/oxide free cut. The photo shows how smooth a radiused feature can be when laser cut without any edge de-burring needed.


Mild steel sheet metal chassis

Thursday, May 14th, 2015

Mild steel laser cut chassis blanks

Mild steel laser cut chassis blanks

Here’s another nice example of laser cutting and bending technology from Trumpf working together to make for an efficient production capability at V and F sheet Metal. We have just produced a batch of 2000 1.5mm thick mild steel chassis blanks on our Trumpf 3030 3KW fibre laser using oxygen as the assist gas. The chassis blanks were produced so cleanly that no edge deburring was needed after laser cutting. The chassis blanks shown here have slight signs of burning from the laser cutting process but this isn’t important as the acid treatments when they are being zinc plated will clean all this off the surface producing a perfect shiny finished component. As ever with laser cutting there were no tools involved and our customer has made several changes to the design with no price impact for them. The next process is to bend the chassis blanks up into there finished form.

Bending mild steel chassis components

Bending mild steel chassis components

The bending process is relatively simple and very quick with a Trumpf 7036 CNC press brake. We have made these chassis components before so the CNC program was already stored on our system server and it was a simple matter calling it back up. The tooling needed, position of the tooling and all bend sequence information is saved for the machine setter to use and then the machine operator to follow in producing each chassis component. A 3D graphic image with each bending stage can be viewed to ensure that the component is bent up correctly ready for inspection. Once the machine is set the Trumpf 7036 is very quick in producing each bend. The sequence of bends is repeated for each component until the batch is completed. The efficient ergonomic layout of the CNC press brake enables an operator to sit at the machine close to the tooling but still safe with the use of laser guards. The machine has it’s own lighting and adjustable work table for optimal position and enabling the operator to work without strain on longer batches of sheet metal work.

Finished mild steel chassis components

Finished mild steel chassis components

The final finished sheet metal chassis are stacked within arms length and at the same height as the bending area to minimise movement and speed up the process. The consistency of laser cutting and CNC bending using Trumpf equipment nicely is demonstrated here.

You may have a sheet metal chassis that you want pricing, it might need CNC punching, laser cutting and CNC bending. We are happy to take a look for you and produce prices and suggest ways that the component can be improved for manufacturing to save you money. Please give our team a call on 01489 577786 or send us an e-mail.


Folded sheet metal work

Monday, May 11th, 2015

Folded Zintec channels

Folded Zintec channels

Here’s a great little idea to save money on sheet metal brackets. We have CNC punched out bracket profiles with all their holes but left them still tagged within the parent sheet metal in separate panels. We have then bent them up in rows of 10 at the same time saving a lot of folding time. The final banks of 10 brackets are sent like this to the customer who can keep them on the shelf and break them out by simply twisting the channels of brackets whenever they want them. The only downside to this method of production is that we cannot deburr the edges as they are still within the folded channel when they are sent out but if you are happy to work with this then it’s a simple idea to save money and well worth considering for components with a consistent cross section.

Please give us a call if you think we might be able to help you with this technique and we will be happy to take a look at your designs for you.

Folded stainless steel housings

Folded stainless steel housings

Stainless steel housings with folded sides and safe edges all around the tops. The safe edges have been produced by over bending to a 30 degree inclusion angle and then as a separate operation closed down with a flat bottomed CNC press brake tool. Once the housings had been folded up with close touching corners the corners joints were seam welded up and then cleaned off smooth before powder coating. These stainless steel housings are typical of the work we manufacture on Fareham, Hampshire, UK with batch of between 50 to 100 off.

Folded housings with multi-bend curved corners

Folded housings with multi-bend curved corners

CNC bending is great at producing straight bent sections. These can be just a slight touch of the sheet producing a 179 degree inclusive angle stiffening bend in large lids etc to stop them panting. Many parts are bent are 90 degress such as support angles, brackets, boxes and lids. Some as the example above can be safe edge profiles where the material is folded right back round on itself. There is another technique that can be carried out when bending sheet metal and that’s multi-bending. Multi-bending can be used to produce curved sections by using a series of small bends at regular intervals to simulate a curve by producing the flats as a tangent to the curve circumference. The advantage of this manufacturing method is the flexibility to use standard press brake top and bottom V tools to produce whatever radius of curve that is needed. This also allows us to modify the program if there are design changes and to deal with variations in material from batch to batch which can be a problem with fixed shape tooling. These parts have been produced on our Trumpf 7036 CNC press brakes which are the perfect machine for this type of work.


CNC punching sheet metal projects

Tuesday, May 5th, 2015

CNC punched aluminium fan panel

CNC punched aluminium fan panel

These aluminium electronic enclosure fan panels have been CNC punched using special shaped tools created to punch out the shapes in singles hits. Each triangle shape in the fan area has a single hit punch and die (although some were created by rotating the shape by 180 deg). The volumes of fan panels and the number of fan positions within each fan panel justified the customer investing in special tooling with the advantage of clean shapes in the component, more accurately produced parts, reduced cleaning up time and cheaper parts with less CNC punching time. These fan panels were then put through a grind master to produce a grain effect on both sides of the plates which removed any marks from the CNC punching process and any that were on the aluminium sheets during handling in the workshop. The final parts were then folded up into a 4 sided tray shape before being treated with Iridite NCP.

CNC punched 0.7mm zintec electrical plates

CNC punched 0.7mm zintec electrical plates

CNC punch presses are great for producing shapes in sheet metal components when the exact punch shaped tool is not available. Sometimes it’s just not be possible to create the desired shape with a single tool; perhaps because the shape is too complex and the tool would be very weak or the tonnage for a single hit would be too much for the punch press or simply there is not the volume requirement to justify the expenditure of bespoke tooling. That’s where a CNC punch really comes into its own with the ability to quickly nibble out shapes with a series of smaller tools to create the desired geometry. These zintec coated mild steel plates are used for supporting heating coils in small fan heaters and are a great example of nibbling out shapes with a series of small tools. You can see from the CNC punched nest that there were several standard rectangular tools used to create the plate end shape by the shape left in the waste material at each end. The advantage of using the Trumpf CNC punch press that we have is that the single punching head design enables each tool in turn to be turned through any angle that is required to produce the component design. This is a great advantage over turret machines with just a few auto-index stations as it allows us to do more with each tool cutting down the amount of time the machine spends on tool changes and frees up the sheet metal component designer to use more angles with features, cut-outs or outer profiles if required.

CNC punched 0.9mm zintec lighting gear trays

CNC punched 0.9mm zintec lighting gear trays

In the two examples above we have seen fan plates CNC punched with special tools made just to produce that job. We have also seen heating plates CNC punched with standard tools that we held on the shelf. This part, CNC punched from Zintec coated mild steel was produced using a combination of special tools and standard tools. The curved shape of the lighting control gear plate was CNC punched using a “banana” tool ground to produce the correct outer circumference needed so the gear plate could fit into a plastic molded light housing. The rest of the features were CNC punched using our standard punch and form tools. In the front towards the bottom of the image there is a small circular formed ring which is for taptite screws to screw into in production. The advantage of using this type of feature is that it allows a self-tapping screw more material to cut a thread into when the component sheet is quite this, in this case just 1.2mm thick Zintec.

I guess the main point to remember when designing sheet metal parts to be CNC punched is that there is a range of ways that components can be produced. We can help you in your design to take advantage of the huge standard tool library we have here on the shelf at V and F Sheet Metal and can advise when it might be appropriate to invest a little bit of money into bespoke tooling to help improve your parts and reduce the part costs. Please don’t hesitate to give us a call and our engineering team will be happy to talk through your deigns with you.