Product category:
General Machining Subcontracting Services
News Release from: Unicut Precision | Subject: Machining medical components
Edited by the Manufacturingtalk Editorial
Team on 21 December 2004
Sliding head autos run 'around the
clock'
Demonstrating its expertise, a machine shop has been running two sliding head autos 'around the clock' machining titanium and SS medical parts needing careful swarf control.
During the summer of 2004, two of Unicut Precision's nine Citizen M32 CNC sliding head automatic lathes were running 'around the clock' producing special connectors for respirators used in the medical industry Unicut Precision, which is based in Welwyn Garden City, now creates around 15 per cent of its turnover from the medical industry which includes production of drill blanks up to 350mm long for femur reamer tools, needle-less syringes, and a whole range of surgical implant screws
This article was originally published on Manufacturingtalk on 27 Apr 2004 at 8.00am (UK)
Related stories
Subcontractor invests in systems integration
To raise productivity a small precision parts machinist has invested some GBP 25,000 in an integrated central communications and production management system.
No blues sung at subcontract machinists'
Such has been the upsurge in the fortunes of Unicut Precision that July and August have set record sales and profit levels for its precision sub-con tract machining business.
As joint managing director Jason Nicholson describes, most materials are difficult to machine and include titanium, 316 implant stainless steel, 17.4 PH medical stainless and Custom 55, which demand special application knowledge and the right machines and tooling.
"But key is swarf control in order to get the material to chip and maintenance of cosmetic super surface finishes are critical," he says.
He explains that the materials tend to be ductile, very sticky and therefore leads to creation of built-up edge on the tools which is a real problem if the set-up is not right.
Further reading
Big order led to new machine purchases
Following the winning of a 12 month contract for three million components from an American fastener company, Unicut Precision immediately ordered two CNC sliding head automatic lathes.
Machining solution was a burner for gas fires
It was the capability of subcontract machinist to provide single operation turning solutions that took some 20 per cent out of the price of gas fire burner heads and ensured total consistency.
Latest sliding head autos reduce costs
Subcontractor, equipped with latest sliding autos, can demonstrate howit can considerably reduce cost, improve quality and consistency of a machined parts in difficult materials.
Also, due to the specialist nature of the material, it is only available as ground stock in certain sizes.
Here, he praises the capability of the Citizen M32 and cites the production of the femur reamers as a classic case.
These are produced by Unicut in batches of between 80 and 150 in a variety of diameters and can be up to 350mm in length.
Following mill/turning these are then sent to another subcontract company for finish grinding.
Because of the most appropriate material stock size only being available at 16mm diameter, it has to be reduced to around 10mm to suit the ordered size of the reamer.
"We are able to balance turn the diameter using two tools simultaneously and rough and finish turn the length of the component to remove up to 4mm of stock in one pass.
As we have the 2000 lb/in2 Cool Blaster high pressure coolant system fitted to our Citizen machines by NC Engineering of Watford, this enables us to run at high speeds and feeds and control both swarf and surface finish! Joint managing director Charles Kenny describes how they had a problem on a certain component with a hole which is 16mm diameter by 50mm deep, which is later cross-drilled using a 7mm driven drill in the cycle.
To break the swarf and get coolant to the cutting area of the tool, the machine used to be set to peck drill at 750 rev/min and 0.12mm/rev feed.
"Now with Cool Blaster we dive straight through at 1,100 revs/min and 0.15mm/rev feed rate and while insert life used to be a maximum of 1,500 parts, it is still running with no signs of wear.
Improvements have also been fed across to the finish boring tool which is now completing its cycle 20 per cent faster than before.
Insert life has also increased from 150 to 500 per corner and we only change then, for security of quality," he says.
The Cool Blaster system has four programmable line outputs which deliver coolant at 140 bar (2,000 lb/in2).
The jets can be operated simultaneously from a central manifold installed on the machine and delivered at up to 20 litres/min.
Each line is selectable, directly from the machining program, to provide high pressure coolant through a five micron filter to different areas of the machine such as the gang tool slide, turret and subspindle.
There is also a through sub-spindle wash that ensures the collet is effectively cleaned between cycles and coolant can be fed directly through the tool on end-working positions.
As the machine has the capability to carry up to 80 tools it is able to use sister tool technology to extend running between normal shifts without interruption.
To Unicut this significantly increases machine utilisation that can be up to 120 hours/week and enables more competitive pricing to the customer.
• Unicut Precision: contact details and other news
• Email this article to a colleague
• Register for the free Manufacturingtalk email newsletter
• Manufacturingtalk Home Page
Search the Pro-Talk network of sites
