The introduction of high-feed milling tooling has provided a significant improvement for Arbroath-based Weatherford International — a leading international provider of oil- and gas-well services.
The cycle time for a procedure requiring the removal of about 90% of the stock has been reduced by 66%; insert consumption has also been reduced drastically.
This project was instigated on the back of other successful process improvement trials carried out at Weatherford’s Arbroath site in co-operation with Horn Cutting Tools Ltd, Ringwood (
www.phorn.co.uk).
The cycle involves machining a set of four identical hockey stick-shaped parts from 40mm-thick steel plate, in this case a relatively soft material that can be easily welded.
The milling process is carried out on a vertical machining centre to a depth of 37mm to leave the components attached to a 3mm-thick base, providing precise location for follow-on machining steps before final separation.
Grant Robb, the Weatherford production engineer involved in the trials, said: “These components are required on a regular weekly call-off. They had been in production for some time using a high-feed milling cutter supplied by another company, but tool life was poor.
“When machining a set of four components, it was necessary to exchange the cutting edge three times. Horn’s sales engineer Dave Reekie was confident that his company’s DAHM system could perform significantly better.”
The trial was quite short, needing only a few program alterations to optimise the application of the Horn tool. The previous set-up used a 40mm-diameter cutter running at 3,500rev/min with 5,000mm/min feed and 0.5mm depth of cut to achieve 90min cutting time — plus three manual insert indexes at 5min each.
For the Weatherford application, the 40mm-diameter Horn DAHM.37.040.D326.05B cutter body with DAH.37.022.N.08.SA4B inserts was run at a spindle speed of 2,100rev/min with 11,000mm/min feed (reduced from 15,000mm/min due to machine constraints) and 1mm depth of cut.
Overall cycle time is now 35min 28sec, and one set of inserts lasts for over 30 sets of components.