Jorns has something against deformations and inaccuracies

Jorns has something against deformations and inaccuracies

The machine manufacturer Jorns has something against deformations at the end of profiles during the bending of profiles or closing parallel open hems: the dynamic positioning function. It compensates deformations, ensuring exact bending results and ‘wow’ effects in the tinsmith’s workshop.


They really do exist: uncompromising professional users who place the highest store by exact bending results simply because this is what their projects need. Jorns, the Swiss manufacturer of bending machines and double bending machines, developed the dynamic positioning (DP) function for them years ago and has now taken this to the next level. Dynamic positioning compensates deformations at the ends of profiles during the bending and closing of parallel open hems. This is only possible because Jorns uses a control technology that allows you to measure, control and position clamping arms individually, and to keep them in position during bending. The clamping force exerted on the part remains even during the bending process: this reduces, or even completely eliminates significant over bending at the ends of profiles.

A remedy for inaccurate and tedious makeshift solutions

Long bending machines, unlike shorter swivel bending machines, have several clamping arms that are driven directly or via control shafts distributed over the entire bending length; when bending profiles, these exert a uniform pressing force on the sheet – over the complete bending length.

  • In practice, the problems usually start at higher sheet thicknesses and when the bending profile is 2 to 3 metres shorter than the machine’s maximum bending length – so that the outermost clamping arms do not grip the material. Until recently, there was only one solution to achieve an accurate bending angle to the very ends of the sheet, no matter whether the clamping arms are driven individually or via a control shaft: insert the sheet strip to keep the upper clamping tool parallel during bending.
  • Previously, accurate parallel open hems could only be achieved through mechanical hem milling that allowed immutable opening dimensions; or by inserting a sheet strip that had to be laboriously removed again after closing. Even precise positioning of the clamping tool across the entire bending length did not allow for a parallel open hem, as the material in the centre of the profile springs back more than at the profile ends.

Improvement with dynamic positioning (DP)

Dynamic positioning allows the uniform closure of a hem over the entire length of the profile; the pre-tension is simply programmed in the control system and lets the clamping arms exert more pressure in the middle of the profile, up to the maximum clamping pressure if needs be. Thanks to the modular design of the machines, Jorns bending machines can also be retrofitted with this function; dynamic positioning can be integrated as an option when ordering new machines. The ‘wow’ effect for the bending accuracy comes for free.

Do you have any questions about dynamic positioning from Jorns? Mr Reto Staeger will be happy to answer them. Email:

Your author

Reto Staeger

Reto Staeger
Head of Marketing & Sales

Phone +41 62 919 80 50


Bending Technology