The process of machining raw materials into designed finished products can generate forces and these inherently can cause material distortion which is difficult to control and can determine the manufacturing process and overall component cost. When machining parts, cycle time is key and higher Metal Removal Rates (MRR) are always a target. However the higher the MRR, generally the higher the clamping forces required to hole the part in the machine too. Historically, to compensate for any distortion observed during the machining process is compensated for by introducing additional process steps. The parts may be rough machined and the clamping forces reduced by either removing the part from the machine or adjusting the clamping forces in the machine tool and this addition of process steps introduces the need for an operator to intervene in the process. This challenge of cost effectively machining parts while managing part distortion can be considered one of the greatest challenges facing the automation of machining precision components.
Currently the part in question is manufactured in a number of operations and cannot be easily automated. This is driving up the cost per unit and therefore becoming not cost effective.
Having looked at the challenge with the company we looked to explore the opportunity of utilising a machine tools inbuilt part probing system as a possible method to measure and automatically compensate for the amount of distortion observed during the machining process. Also, by moving the machining of the part from a milling machining to a multitasking machine enabled manufacturing of the part in one operation without any operator intervention.
Moving of the clamping position almost completely eliminated the distortion observed. We also successfully used the machine part probing system to measure and automatically adjust finishing cuts to machine the part into tolerance.
Following test cuts at our lab in Mullingar we clearly demonstrated how to and successfully machined the part in one operation. This will enable the client to deploy an automated method of manufacture greatly reducing cost per unit and remain competitive with their customers.
The client also has developed a deeper understanding of the impact of workholding and to challenge more parts they produce and look for opportunities to automate.
“We used IMR recently to investigate an ongoing issue we were having with material distortion on a family of parts that we manufacture, that went through a number of processes. Along with the distortion issue, we also required to try minimise the number of processes involved, with regard to time, costs and the possible implications of Covid. The research that IMR carried out and the expertise that was shared, has been a huge help in solving these issues and food for thought on how we process similar parts in the future.”
(Patrick Coldrick, Sales/Business Development Manager)
Machining Applications Specialist
Design for Manufacturing