Blog by managing director Alan Pickering, who was part of the team that invented the first all-electric tube bending machine in the 1990s.
What is Carriage Push and when can it be useful?
Carriage Boost or Carriage Push is a bit of a strange one, but essentially is used to apply force to the end of the tube.
Why might you use it ?
Similar to Powered Follower it applies a force to the tube along its length and is most useful when you have a very short Clamp Length typically down to 1D (1 x Diameter) to reduce/eliminate Clamp Slip, the scourge of any tube bending application.
Eliminating Clamp Slip is your number one priority when setting up a tube bending application after getting your tooling in the right position.
By applying Carriage Boost to the end of the tube you can help the clamp by preventing slip and sometimes allowing a bending machine to bend at a higher torque than it was designed to do.
The down side of Carriage Boost is that it applies force equally around the circumference of the tube OD, when you are trying to do difficult tube bending applications that require the material to TeaPot, (as discussed in the Blog : Control Features : Powered Follower) i.e.. material to advance of the outside of the bend and come back on the inside of the bend you can see the obvious conflict, this conflict will result in Wiper Die wrinkles if you push for too long.
Some control systems like Unibend allow you to profile the Carriage Boost so that you can push at the beginning of the bend and back off when the material has started to “flow”.
It has been known to profile the interface to the collet so that it is applying the boost only to the outside of the bend. But these interfaces bring with them their own challenges and are not really suited to high-volume production.
These interfaces need to be made of special expensive materials and are prone to snapping as they typically need to be made of the same size as the wall thickness of the tube so that they can pass over the mandrel.
When short straights are required it may be necessary to use a Pipe Plug or a Multi-Stack / Multi-Radius Machine – to be discussed in the next Blog.
Got a question for our expert team? Get in touch now – sales@unisonltd.com
