What is CNC bending?
Yes this is a good question, what is CNC bending when applied to sheet metal work?
Computer numerically controlled (to give it its full title - CNC) bending is a production process that is carried out by CNC brake presses (sometimes also known as CNC press brakes for some reason). These manufacturing machines can bend and form sheet metal components from just a few mm across to lengths many metres long on some of the largest industrial CNC press brake machines. Theny can have a range of forces so very thin to incredibly thick plates can be bent up. CNC press brakes may either have a fixed bottom bed with the bending V block tooling secured in place and a top beam which travels under hydraulic or electrical force with the V blade tools, this is known as down forming. The opposite is known as an up forming machine with the bottom bend moving up and down and the top beam fixed. Both bending process methods will produce the same sheet metal work and there are no restrictions to the design of your component to suit either of these machines. We have down forming Hydraulic CNC press brakes (Edwards Pearson PR3 and PR6) down forming Electrical CNC press brakes (Trumpf 7036) and up forming Hydraulic CNC press brakes (Guifil PE6-16) and they can form the same type of bent sheet metal work.
The CNC press brake is basically programmed to accept the sheet metal work flat developed blank at a given distance which is defined by the programmable back stops, which defines the point where the bend will be formed. The distance that the programmable V blade enters into the V block then defines the angle achieved of the final bend, the further the V blade enters into the V block the tighter the final V bend will be. The sheet metal component can be a combination of different bend lengths and angles (up and down) generated by the CNC program positioning the sheet metal work blank at defined positions and programmed angles.
The maximum length of the sheet metal component that can be formed up is obviously defined by the length of the CNC press brake machine's bed but the thickness of material is a function of the sheet metal material's tensile strength and the tonnage available from the machine to form the sheet metal components. The larger the bottom V block opening the greater the sheet metal thickness (gauge) that can be bent for the same machine tonnage. But, as the V block opening is increased so does the internal radius of the bend on the final sheet metal component.
If you have a sheet metal component that you are designing but not sure whether it can be bent using CNC press brakes and CNC tooling then send us a copy of your drawing or give us a call and we will take a look for you.
CNC bending sheet metal work
This is a typical thin gauge sheet metal component that has been bent up by using a CNC press brake. This particular component has been manufactured from 0.9mm Zintec coated mild steel and is used to hold control gear for light fittings. The bend stages are all controlled by the CNC press brakes's CNC program. This can specify how many bends a component may have, the angles, the position and which side of the components the bends are to be placed. Accuracy and efficiency are further increased by the use of a multi-axis CNC back gauge systems enabling the most complicated sheet metal work to be bent in one machine set-up and manufacturing cycle repeatably and without delay. All CNC bending programs are stored on a computer network server allowing instant access to production bending information therefore reducing the time taken to set up each job in production enabling work from samples to volume production to be dealt with quickly and effciently.
With offline Trumpf Tru-Bend software linked to our Radan 3D modelling software V and F Sheet Metal's engineering sheet metal CNC programming department can test out the optimum CNC bending solution to suit your sheet metal work component's needs before cutting any actual sheet materials. Time and material costs can be reduced helping to offer you the most competitive component prices. The combination of bending speed in conjunction with our Trumpf Tru-Bend off line CNC programming system definitely makes this the complete production package for a sub-contract engineering company looking to bend small sheet metal work up to 1M in length. Our capacity is extened further with the use of Edwards Pearson 2.5M long CNC press brakes.
Bend data for designing sheet metal with single bends
When designing any sheet metal component with a single bend it is important to know the minimum size that can be produced for any combination of material and gauge. If you take a look at our website we have tooling tables which can help you with your designs to reduce the need for special tooling.
Bend data for designing sheet metal with double "joggle" bends
When designing any sheet metal component with a double or "joggle" bend it is important to know the minimum size that can be produced for any combination of material and gauge. If you take a look at our website we have tooling tables which can help you with your designs to reduce the need for special tooling.
Bend data for designing sheet metal with U bends
When designing any sheet metal component with a U bend it is important to know the minimum size that can be produced for any combination of material and gauge. If you take a look at our website we have tooling tables which can help you with your designs to reduce the need for special tooling.
CNC press brake tooling and bending in action
CNC bending sheet metal components with a Trumpf 7036 - sheet metal mild steel gear box housings
CNC bending sheet metal work on a Trumpf 7036 electric press brake. From the simplest 1 bend angled component to very complex sheet metal components all tackled without a problem on these CNC press brakes.
CNC bending with an Edwards Pearson press brake - sheet metal housing fabrication
CNC bending 3mm thick mild steel sheet metal housing on a 65 ton CNC press brake. The top tool has a round form which the sheet metal fabrication form follows but the bottom tool is using an air bending technique so just needs to support the sheet metal at the start of the bend.
Sheet metal work used in the UK Lighting Industry
Sheet metal box with CNC bending and hand folding features
Here's a typical sheet metal component that we manufacture for the Lighting Industry in the UK. We CNC punch out these small pre-painted mild steel enclosures and CNC bend some of the bends into the component using CNC press brakes. Other bends are applied to the component by hand along pre-punched lines of CNC punched slots. This enables our customer to enclose an electronics component and finish the sheet metal component around the component without any fixings.
LED Light Fitting using aluminium sheet metal enclosure
Complicated CNC bent enclosure
Here's a typical sheet metal component we have manufactured from thin gauge aluminium that has been CNC bent and powder coated before being screwed together. This batch of components were CNC programmed based on our customer's designs and manufacured in just a few days. This flexibility is possible by using modern CNC punching and CNC bending manufacturing machines.
Typical CNC bent sheet metal components - all produced on our Trumpf 7036, Edwards Pearson and Guilfil CNC press brakes
Sheet metal reflector for the UK Lighting Industry - Reflective aluminium
Reflector for a ceiling fitted down light. The individual parts of the reflector are CNC punched and CNC bent using Trumpf technology and then clipped together with tags and slots to locate all the sheet metal parts.
Sheet metal software model
3D models are really important to us at V and F Sheet Metal when we program a new sheet metal fabrication. We use them to calculate the correct cut size for all the sheet metal developments and to make sure all parts can fit together before we CNC punch and CNC bend any material in manufacturing.
Text with BIG Picture
Stainless steel cover for a heater unit created using multi-bends on a CNC press brake. Bu altering the length and angle of each bend the cross section can be created in the sheet metal, in this case it was an elipse.
Stainless steel spring clips - Spring clips used in light fittings
Small components such as these stainless steel spring clips are typical of the sheet metal work that can easily be bent on our Trumpf 7036 CNC press brakes. These bracket are used to clip aluminium reflectors into large light fittings without the use of screws and nuts.
Comments on CNC bending of sheet metal work
vandfsheetmetal (author) on July 11, 2012:
@RindgeLeaphart: Hi, I'm glad that my lens on CNC bending sheet metal work was of interest to you. I have lots more examples of sheet metal manufacturing processes and examples of past sheet metal projects on my website at www.vandf.co.uk that you might like to look at or visit some more of my sheet metal squidoo lenses.
RindgeLeaphart on July 11, 2012:
Having worked in several CNC shops, I found your posting to be quite insightful.