Product category:
Subcontract machining and assembly services
News Release from: H C Holifield (Oxford) | Subject: Machining practice
Edited by the Manufacturingtalk Editorial
Team on 11 November 2003
How to hold price when having to change
process
Cost of production needs to be looked at closely by subcontractors in order to win business and maintain profitability, especially when components are relatively simple.
Cost of production needs to be looked at closely by subcontractors in order to win business and maintain profitability, especially when components are relatively simple Single-hit machining is usually the watchword
This article was originally published on Manufacturingtalk on 3 Dec 2003 at 8.00am (UK)
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One feature of a contract machining service that sets it apart from other subcontractors is the extensive 'consignment stocking' service it provides to customers.
However, plant availability has to be taken into account and the best machine for the task is not always available.
One job completed this autumn by Holifields, Abingdon, involved metalcutting operations on both ends of a disc-shaped, copper flange that would have been ideal for complete machining on the contract machinist's hanging-spindle lathe with live tooling and a turnover station.
Unfortunately the VTL was producing a long run of another component.
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Pick-up spindle VTLs installed to reduce costs
Another example of the increasing popularity of self-loading vertical turning lathes are the two installed by a contract machinist to keep production costs down.
To achieve a similar result at a competitive price using one of its vertical machining centers, albeit with manual intervention to reverse the component, Holifields decided to fixture two parts at a time in the machining area, one in a 4th axis rotary table (A) and the other in a conventional clamp (B).
The 98 mm diameter, copper flanges for a medical equipment manufacturer had first to be turned on the OD to produce a 5-degree taper.
A turned blank was clamped in fixture A in the machining centre and during Op 1, a central bore was interpolated and four further holes on a PCD were through-drilled and countersunk.
The operator then reversed the part and clamped it in B, placing a new blank in A.
In the next cycle, Op 2 on the other side of the first component involved milling slots on a diameter either side of the bore and drilling a blind hole in one of the slots.
Op 1 was completed on the blank before the operator opened the doors to remove the finished flange from B, transfer the part-machined component from A to B and clamp a new blank in A.
Dimensional tolerances were down to +/-0.1mm.
Around 75 per cent of Holifields' business is directly or indirectly in the medical sector.
A feature of the company's service that sets it apart from that of most subcontractors is the extensive 'consignment stocking' it provides for customers, as in this case.
Single components, kits of parts, sub-assemblies and complete assemblies are produced to an agreed schedule by Holifields and are stored at its Abingdon premises free of charge for KanBan or scheduled delivery, or for call-off by the OEM.
Alternatively, Holifields takes responsibility for interrogating larger customers' intranets and automatically fulfilling the requirement for the next period.
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