Machining Process

For the trigger in the XT3 Pistol grip the previous process made use of brass stamping process to create the profile with then additional machining operations to manufacture the finished product, During early 2023 the company who provided the brass stampings went into administration and the process was moved to an inhouse manufacturing by machining the profile out of aluminium billet plates.

The program was then created using Fusion360 CAM to give a program. Once the process was defined for manufacturing a process document must be made. (K22) (K6)

During the manufacture the process is a combination of proving out the process and creating production stock. This means that manufacturing problems may occur during the process and these must be resolved to avoid a delay in the production process The process involved using advanced/modern CAM systems to create components from (B3)

Manufacturing Issue 1

The first issue was a misalignment between OP1 and OP2, During the change over a slight misalignment caused a visible step in the full profile. There are a number of possible corrective actions here. (S3)

  • Add some probing holes to measure the exact position between OP1 and OP2
  • Adjust the offsets slightly to align correctly
  • Alter the profile in such a way to avoid this kind of overlap in the component.

Ultimately a combination of changing the offset and reducing the profile was chose due to the fact that adding a probing cycle would increase the cycle time and be a detriment to the production efficiency.

This approach actually improved the cycle time as the cutting distance was reduced, Following the principle of less is more in this circumstance means that we reach out goal without introducing further complexity into the manufacturing process. (K7)

Manufacturing Issue 2

The second issue was a problem with the tagging out operation and the slot machined in the clear area. The material was not being removed correctly due to an approximate placement of the tags and therefore a problem with excess stock left on the partial profile as show in the image below.

For this we have a number of options to resolve

  • Increase the width of the slot to ensure all material is removed
  • Remove material by hand for worse case examples, allow tumbling process to remove excess material
  • Modify the tagging segments to ensure minimal residual stock remains.

Due to the volume of material removal I elected to remove the material by hand for the worst examples due to misalignment. I would be doing this personally as to avoid personal conflicts with other departments during integrating the process into the shop floor. (K15) (K8) This procedure was then added to the process document to ensure that it is complied with throughout the manufacturing process

Furthermore this documentation is important to follow as the manufacturing process was handed off to the machine tool operators to run the program and ensure quality control is tight. The above issues came from highlighted issues and communications with the milling operator (K2) (K8)

For future operations I made use of advanced CAM features to ensure Continuous Rest Machining showing the previous operation to ensure the tag material is fully removed

All documentation must be fully recorded as in with ISO9001 (K5) And these documents must be followed by the operator running the machine. It is accessible on the network drive as PDF and some machine controls allow this to be read on the machine controller establishing a recorded and primary line of communication between operator and CAM programmer (K8)

The above was solved inline with a PPS approach (K1)

Manufacturing Data Control & Testing

Manufacturing data control is controlled by SAP HANA ERP. This performs a series of important functions of the business

  • Stock management
  • Employee Time Management

Once the program was evaluated for manufacturing time this is then inputted into SAP, Operators will then scan in the Work Order created from the part number and will collect operator data

(K16)

Furthermore as manufacturing continues the process can be monitored with various inhouse utilities to examine the efficiency of work carried out. Moving to aluminium over brass is certainly a more ecological process as aluminium is one of the most recycled materials and improving the efficiencies means that there is less total energy expenditure during the manufacturing process. (K17)

Testing

Due to the change of material there was a requirement for testing before putting the units into production and manufacturing. This testing was carried out with the collaboration of the Design department to ensure that the trigger will conform to the previous standards of the brass stamped component in a destructive manner. (K20)

The trigger was cycle worn with an oscillating mechanism on a lathe until destructive failure occurred. This was in excess of a million cycles and its indeterminant if the mechanism locked up causing catastrophic damage as opposed to failure of the replacement component

Process Document Control

All of the above documentation is linked in with the Production Engineering Process Document Control system inside of the ToolNFixture Database under the number B16-0012 (K10) (K14) They are written in the markdown format and then exported as a PDF file for either distribution to the machining centre or printed to the operator (S6), version control is managed by Git and the prehook exports the file to a pdf automatically.

Components are inspected through measurement with digital callipers in accordance with drawing standards. Nonstandard features are measured using radius gauges.

(S1)

Future Improvements

At a later date there is scope for making use of advanced probing features in the Fusion360 CAM package for surface inspection, Although we currently do not have the required software package this is an advancement that could be considered to reduce operator requirements and increase manufacturing efficiency’s

This project was completed under the CNC Action Group. This team is dedicated to making continuous manufacturing improvements to uphold and strengthen the manufacturing capability on the Bradford site with multiple connected stakeholders such as

  • Direct Managers
  • Directors
  • CNC Operators
  • CNC Programmers
  • Specials Manufacturing (Consultation) (B6)