Turner Model 911.25 - The Worlds Smallest Tube Straightening Machine
Straightening Very Small Tubing - A Difficult Straightening Application
As the outside diameter of tube gets smaller and smaller the difficulty in rotary straightening slowly increases.
Historically tubes with outside diameters below 0.080” [2 mm] have been difficult if not impossible to straighten on rotary straightening machines. Tubes less than 0.060” [1.5 mm] have been straightened on manually operated devices including a device commonly known as a “whizzer” . All such devices have never really been controllable and at best produced inconsistent tube straightness.
Over the years, other machinery designers have made honest, but unsuccessful, attempts at designing a conventional rotary tube straightener to handle tubes down to 0.040” [1 mm] tube OD. Makers of stainless steel tubing used in the medical industries has been searching for a machine to precision straighten very small and thin wall tube for many years.
Two Years In Design & Development
Turner has long been known as a company that would take on the design and manufacture of straightening machinery that needed a unique approach or feature for a specific customer.
For some years Turner had looked at the possibility of adding a miniature precision straightener to its range but considered that the chance for total success were at best 50/50.
However, during 2005/6 Turner had engineered improvements to two small tube diameter straightening machines made by competitors which resulted in a definitive improvement in their capability.
In late 2006, a well respected company again approached Turner and requested that Turner consider the development of a precision straightener to handle high yield, thin wall stainless steel tube down to 0.040” [1.0 mm] OD. Both the customer and Turner understood that this venture was fraught with difficulty and posed significant financial risk. After much discussion, deliberation and because of the very long successful relationship, a decision was finally made to proceed with a project to design and develop a fully computer controlled miniature 10 roll precision rotary straightening machine.
As a result the Turner model 911.25 10 roll CASAM I machine with digital tube pressure sensing system was born.
With an outline conceptual design completed, the next few months were devoted to testing a variety of machine components to be sure they would perform within the machine. At the same time, software engineers worked on changes to the CASAM software to enable the resolution of the system to be advanced by a factor of 10 to enable very small changes in roll position and pressure applied to be monitored and recorded. Vital features if the machine was to be successful.
The machines design was frozen after 6 months of component testing and the first machine was issued to production for part manufacture and assembly.
The finished model 911.25 machine was powered up in January 2008 and ran its’ first proving trials.
The ability to set roll positions with extreme precision was proven within the first day or two of machine testing. The measurement of the pressure being applied by each pair of rolls digital tube precision was more accurate that had been foreseen and as anticipated proved to be totally necessary to control the tube as it was threaded up and run through the machine.
The Turner auto-acceleration drive system enabled very accurate and easy tube thread-up into the 5 pairs of machine rolls and the ejection of the tube end from the machine at the end of running the fully automatic straightening cycle.
The machine flew through a series stringent tests in the Turners’ Salem, Ohio plant and within 3 months was fully operational in the customers plant.
The worlds’ smallest precision rotary straightening machine had been conceived, born and raised to adulthood in less than 2 years. A testament to the ability and experience of the team of engineers at Turner.
The machine is configured with 5 pairs of rolls all driven. The rolls can be adjusted in height and angle as per common practice to enable tubes of different diameters to be accommodated.
The roll to tube pressure sensing is accomplished by strain gauges fitted into the base of the machine.
Extremely accurate roll RPM’s are achieved by two AC vector drives with unique control that ensures the tube is maintained on the center line of the machine.
The new model 911.25 10 roll CASAM I precision straightening machine is capable of straightening tubes from 0.040” [1.0 mm] up to 0.100” [2.5 mm].
A short video featuring the new machine can be seen at
CASAM is an acronym for Computer Aided Setting And Management.
The CASAM system is now in its 3rd decade of operation and with continual development is the standard by which competing systems are judged.
Neill McLachlan B.Eng.
Turner Machine Company, Inc.1433 Salem ParkwaySalem, OH 44460Call 330 332 5821 Ext 114Mobile 330 429 2947