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09/03/2010
5 axis Milling plus much more with HyperMills CAM Software
On Stand 5150 at MACH 2010, OPEN MIND Technologies will be giving its UK debut to a number of new..
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08/03/2010
New Chamfering tools to perform drilling, milling, spotting, countersinking and chamfering operations
Adding to ITC’s extensive drilling line and 4111 Series of chamfering tools, the company has now..
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08/03/2010
CNC Machine Shop Cleaning system debuted at Mach 2010
Air Cleaning Systems will be demonstrating its exceptional airborne particulate removal systems and
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07/03/2010
Machine Tool Supplier Haas Automation Recruits Paul Jesson
Paul has a wealth of experience in the machine tool industry and will help Haas to continue..
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Star sliding head machine- Rotamic Precision
Story added 02 July 2009.
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A stainless steel shaft for an aerospace fuel system is machined at both ends in one hit from S143 aerospace stainless steel bar in a reduced cycle time on the Star SR-20RIII sliding-head lathe at Crediton subcontractor, Rotamic Precision Engineering. Previously, the part needed three separate operations on a fixed-head lathe and a vertical machining centre (VMC). The reduction in cycle time has enabled Rotamic to achieve its cost reduction target from the customer.
Gary Squires, Rotamic’s workshop supervisor, commented, “We used to have trouble holding 25 microns total tolerance on three stepped outside diameters (OD) turned down to around 4 mm from 9.5 mm bar.
“Even though the 89 mm long part was supported by a tailstock and running centre in the fixed-head lathe, flexing of the bar used to cause tool push-off and resulted in scrapped components.
“Now, with the Star sliding head machine, the guide bush supports the component close to the point of turning, so every part is perfect.”
A more complex, mating part in the same material is also produced in one hit on the multi-axis Star mill-turning centre more quickly and cost effectively than before. The part is manufactured in batches of 800-off in eight varieties and each previously needed four separate operations, as follows.
On a single-spindle, fixed-head lathe, the component was OD-turned from 12.5 mm diameter bar and threaded, then reversed by hand and held on the thread end while a pear shape was turned at the other end. The part was transferred to a Haas VMC for flats to be milled on either side of the pear and for a 4 mm diameter through-hole to be drilled and reamed. A second operation on the VMC put a 45-degree chamfer on the edges of the flats.
Mr Squires continued, “As with the shaft component, total tolerance is 25 microns on a number of features such as OD, shoulder position to centreline, and diameter of the coaxial hole in the end.
“Again, tolerance was difficult to hold, despite the part being much shorter. There is no problem achieving the required accuracy on the Star. We can also carry out much of the deburring in-cycle, which we could not do before, so parts are transferred more quickly to the rumbler.”
Installed in October 2008 by Star Micronics GB as a turnkey solution for production of two components, the 20 mm capacity lathe, fitted with an FMB 3.2 metre bar magazine, was Rotamic’s first sliding-headstock machine. Star GB programmed the shaft as well as the largest of the mating parts and successfully machined 30 of each at its Derbyshire technical centre to prove out the processes.
At present, over 90 per cent of components put onto the Star are of stainless steel, so Rotamic went for the 100 bar, high-pressure coolant option, which blasts the stringy chips away from the working area. Oil mist extraction and filtration have also been fitted. So too has a long parts ejection system that sits at the counter-spindle end of the machine to accept machined shafts so that they do not into the machine and risk damage.
Rotamic has AS9100 accreditation and mainly serves the aerospace industry, although work is regularly carried out for the medical, offshore and hydraulics sectors. It had known for some time that a sliding headstock lathe was ideal for mill-turning many of the shaft-type components it manufactures, but had always been reticent to take the plunge into the new technology.
Continued Mr Squires, “We used to think sliding head machines took a long time to set up, perhaps as much as a day, but it is not so. We were amazed to find that we can reset the Star quickly and be straight back in production, provided that the guide bush does not need changing to accommodate a different size of bar.”
“Another preconception we had was that sliders are difficult to program, but that is not true either - quite the reverse. Ease of set-up and programming encouraged Rotamic to transfer 66 parts from its fixed-head lathes to the Star in the first seven months of operation. They were mainly shaft-type components with prismatic machining content and a requirement for reverse end machining, even if it is just facing to length.
All of the components are produced faster and more economically on the sliding-head machine, thanks to single-hit machining, fast axis movements including 35 m/min rapids, and Star’s proprietary motion control system built into the Fanuc control.
Mr Squires said that there is little work under 20 mm in diameter that cannot be transferred economically to the SR-20RIII. Some parts are very small indeed, such as a 1.6 mm diameter dowel for an aircraft motor housing, which is turned to ± 6.25 microns tolerance.
While a majority of the parts produced so far on the Star have been of stainless steel, with a little brass and aluminium, other more exotic materials are routinely machined by Rotamic. They include titanium and nickel alloys and Stellite, a cobalt-based, high-temperature superalloy that is particularly problematic to machine. Production of some of these components may also be transferred to the SR-20RIII.
It prompted Mr Squires to conclude that the Star machine was ed in preference to other sliding-head lathes due to its robustness of build, higher power and heavier installed weight, all of which make it more suited to machining difficult material.
The other facet of Star GB’s turnkey package that the customer appreciates is the approach and professionalism of the staff and the 24/7 back-up, which in Mr Squires words has been “brilliant”.
Gary Squires, Rotamic’s workshop supervisor, commented, “We used to have trouble holding 25 microns total tolerance on three stepped outside diameters (OD) turned down to around 4 mm from 9.5 mm bar.
“Even though the 89 mm long part was supported by a tailstock and running centre in the fixed-head lathe, flexing of the bar used to cause tool push-off and resulted in scrapped components.
“Now, with the Star sliding head machine, the guide bush supports the component close to the point of turning, so every part is perfect.”
A more complex, mating part in the same material is also produced in one hit on the multi-axis Star mill-turning centre more quickly and cost effectively than before. The part is manufactured in batches of 800-off in eight varieties and each previously needed four separate operations, as follows.
On a single-spindle, fixed-head lathe, the component was OD-turned from 12.5 mm diameter bar and threaded, then reversed by hand and held on the thread end while a pear shape was turned at the other end. The part was transferred to a Haas VMC for flats to be milled on either side of the pear and for a 4 mm diameter through-hole to be drilled and reamed. A second operation on the VMC put a 45-degree chamfer on the edges of the flats.
Mr Squires continued, “As with the shaft component, total tolerance is 25 microns on a number of features such as OD, shoulder position to centreline, and diameter of the coaxial hole in the end.
“Again, tolerance was difficult to hold, despite the part being much shorter. There is no problem achieving the required accuracy on the Star. We can also carry out much of the deburring in-cycle, which we could not do before, so parts are transferred more quickly to the rumbler.”
Installed in October 2008 by Star Micronics GB as a turnkey solution for production of two components, the 20 mm capacity lathe, fitted with an FMB 3.2 metre bar magazine, was Rotamic’s first sliding-headstock machine. Star GB programmed the shaft as well as the largest of the mating parts and successfully machined 30 of each at its Derbyshire technical centre to prove out the processes.
At present, over 90 per cent of components put onto the Star are of stainless steel, so Rotamic went for the 100 bar, high-pressure coolant option, which blasts the stringy chips away from the working area. Oil mist extraction and filtration have also been fitted. So too has a long parts ejection system that sits at the counter-spindle end of the machine to accept machined shafts so that they do not into the machine and risk damage.
Rotamic has AS9100 accreditation and mainly serves the aerospace industry, although work is regularly carried out for the medical, offshore and hydraulics sectors. It had known for some time that a sliding headstock lathe was ideal for mill-turning many of the shaft-type components it manufactures, but had always been reticent to take the plunge into the new technology.
Continued Mr Squires, “We used to think sliding head machines took a long time to set up, perhaps as much as a day, but it is not so. We were amazed to find that we can reset the Star quickly and be straight back in production, provided that the guide bush does not need changing to accommodate a different size of bar.”
“Another preconception we had was that sliders are difficult to program, but that is not true either - quite the reverse. Ease of set-up and programming encouraged Rotamic to transfer 66 parts from its fixed-head lathes to the Star in the first seven months of operation. They were mainly shaft-type components with prismatic machining content and a requirement for reverse end machining, even if it is just facing to length.
All of the components are produced faster and more economically on the sliding-head machine, thanks to single-hit machining, fast axis movements including 35 m/min rapids, and Star’s proprietary motion control system built into the Fanuc control.
Mr Squires said that there is little work under 20 mm in diameter that cannot be transferred economically to the SR-20RIII. Some parts are very small indeed, such as a 1.6 mm diameter dowel for an aircraft motor housing, which is turned to ± 6.25 microns tolerance.
While a majority of the parts produced so far on the Star have been of stainless steel, with a little brass and aluminium, other more exotic materials are routinely machined by Rotamic. They include titanium and nickel alloys and Stellite, a cobalt-based, high-temperature superalloy that is particularly problematic to machine. Production of some of these components may also be transferred to the SR-20RIII.
It prompted Mr Squires to conclude that the Star machine was ed in preference to other sliding-head lathes due to its robustness of build, higher power and heavier installed weight, all of which make it more suited to machining difficult material.
The other facet of Star GB’s turnkey package that the customer appreciates is the approach and professionalism of the staff and the 24/7 back-up, which in Mr Squires words has been “brilliant”.
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