Turnkey CNC Machining and Fixturing for Manufacturing of Brake Calipers

John Hart was commissioned by one of the largest automotive brake manufacturers in the world to undertake this very large turn-key project. The brief was for John Hart to assume responsibility for all aspects of the project from fixture design through to a production ready machining cell.
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This project consisted of 32 individual brake caliper bodies and brackets and included the design of 38 individual work holding fixtures with over 50 machining fixtures being supplied. In addition John Hart Technology handled the design and supply of more than 40 measuring fixtures that were installed on the client’s co-ordinate measuring machines for the project.

After supplying all fixtures, John Hart engineers were tasked with the creation of the CNC machining programs for all products. More than 200 individual programs were created.


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John Hart engineers were then responsible for all aspects of process capability testing working closely together with the clients’ quality staff and the cutting tool vendors to achieve the most time efficient result.

The final result was a machining cell containing more than 20 CNC vertical machine tools, all with the proven ability to run production on any of the 32 different brake caliper products. From the first meeting with the client to a production ready machining cell, this projected was completed by John Hart in less than one year.


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Turnkey CNC Machining and Fixturing for Manufacturing of Suspension Knuckles

John Hart was commissioned by a world renowned supplier of suspension components to the global automotive industry to undertake a turnkey project for suspension knuckles in Shanghai, China.


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During this very detailed project, John Hart undertook the following tasks: Fixture design and build, cutting tool interference checking, machine collision checking, CNC programming, first article sample cutting.

The project consisted of 4 individual parts, which included two front knuckles (left hand and right hand), and two rear knuckles (left hand and right hand), and included design of 6 fixtures with 8 units of fixtures being built.

The fixture consisted of base plate, main fixture plate, nest blocks, datums, arms, clamp points, guide blocks, imported hydraulic clamps and valves, and auxiliary pieces.


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The fixtures were designed to suit horizontal machining centers with B axis tables and a vertical machining center, and adopted low pressure multi-action hydraulic sequence, operated under 7MPa system pressure with the clamping action and pressure controlled by a custom designed, intergral valve block on the fixture.

Each fixture had two nests or more, to make full use of machining envelope, and to reduce operator load-unload time. The process and CNC program were also planned carefully to achieve less tool changing time and tool path time. More parts were cut before changing another tool.

The fixtures had following characteristics:

  • The fixtures were internally hydraulically ported.
  • The fixture components were designed with high accuracy and interchangeability in mind so that the spare parts could be changed quickly, without requirement for additional adjustment.
  • The fixtures had air sensing functionality (supported by machine side function), for error proofing, to prevent defect machining parts by incorrect loading.
  • The fixtures were able to control and regulate the hydraulic pressure and sequence of each hydraulic line, which was convenient for adjustment of clamping force of fixtures during run-off, so as to control the part deformation.

The fixture was able to meet process capability (Cpk) within the strict and demanding timing and technical constraints that are applied to all high class automotive projects.


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Engineered CNC Workholding Fixtures Australia

John Hart leverages 70 years of practical understanding of CNC machine tools to design and build engineered CNC workholding fixtures that produce unmatched efficency gains and precision.
John Hart specializes in developing turnkey CNC machining solutions that significantly boost productivity, offer safer operation and facilitate automation in more complex setups.

We have a wealth of experience covering the installation of CNC workholding fixtures onto customer’s machines, working closely with tooling companies, programming the components and completing the CNC fixture and tooling run off to a specified CpK.

These capabilities allow us to offer full turnkey CNC machining solutions to our customers and our team of designers, machinists, engineers and production managers will be involved every step of the way until the job is delivered, on time and on budget.


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From customer consultation, to 3D CAD design, animation, tool interference checking, CNC fixture manufacturing and functional testing, through to full run-off on your CNC machine tool including statistical process analysis, we can do it all.
Process Planning

workholding fixtures process planningJohn Hart engineers have a great depth of experience in advanced CNC machining techniques, efficient cutting strategies and rigid, repeatable CNC workholding solutions.

Using this experience, John Hart project engineers will sit down with the client to discuss the required project outcomes in order to tailor a customized turnkey manufacturing solution.

At this time, the following will be formulated and presented to the customer for further discussion:

  • Detailed machining time study proposal which outlines projected cycle times and number of CNC machines required for required production volumes
  • Conceptual 3D work holding proposal
  • Projected project time line

It is at this stage that the details of each important element of the project are discussed and mutually agreed upon by both the customer and John Hart engineers.

Project Planning

workholding fixtures project planningUpon completion of the Process Planning stage, John Hart engineers will prepare a detailed project time line projection for the clients’ approval.

John Hart Technology has the resources and experienced engineering team to undertake responsibility for the entire turn-key project on the clients’ behalf, delivering the client a production ready manufacturing cell.

The key components of a typical turn-key project are:

  • Liaising with CNC machine tool vendors on technical and timing details
  • Management of CNC cutting tool vendors from process concepts through to production ready cutting tool delivery
  • Design, manufacture and supply of rigid, repeatable CNC workholding solutions
  • CNC machine programming
  • Installation and commissioning of CNC workholding fixtures on machine tools
  • Run-off and capability testing of clients’ process

Each of these components are carefully included in the overall project plan by John Hart engineers using a wealth of turn-key project experience, particularly on automotive projects.


workholding fixtures designUpon commencement of the design stage of a project, John Hart design engineers will create CNC workholding concepts in 3D which are tailored to the specific requirements of the client. These concepts will be presented to the client for feedback and approval before the final design begins.

Using the feedback from the client, John Hart design engineers will create a final CNC workholding design ready for manufacture. During the final design, the following key items are factored in.

  • Maximum rigidity by design, clamping forces and positions are carefully calculated
  • Internal hydraulic porting to ensure a clean and tidy design which reduces unnecessary swarf build up on the CNC fixture
  • CNC cutting tool clearances checked in 3D before manufacture to avoid complications further into the project where the timing impact is far greater
  • Most effective clamping sequence for secure and accurate part clamping
  • Quick and cost effective replacement of any consumable items such as datums and clamping points
  • Modular CNC fixture design to allow for flexibility in manufacture
  • Pneumatic part presence sensing to ensure parts are clamped securely and accurately

The final design will be submitted to the client for further feedback and approval prior to final manufacture release.

Cutting Tools

workholding fixtures cutting toolsOne of the most important components of a successful turnkey machining project are the CNC cutting tools.

With a long and diverse history of successful CNC machining turnkey projects working together CNC cutting tool suppliers, John Hart has built strong technical partnerships with the worlds largest cutting tool organisations.

With the strength of these partnerships John Hart is able to work closely with their design and engineering teams to ensure all bases are covered before the CNC cutting tools and CNC fixtures are manufactured. This translates into the most time efficient result once on the clients site.

As we conduct full cutting tool and fixture interface checking in the 3D space during the CNC fixture design phase, the following can be achieved:

  • CNC cutting tool interference avoided completely
  • CNC cutting tools can be designed to be as short and rigid as possible
  • Both the CNC fixture and CNC cutting tools can be altered and checked prior to manufacture allowing the best and most effective tooling choices to be made from the beginning
Build & Test

workholding fixtures build and assemblyUpon commencement of the build and test phase of the project, John Hart project engineers carefully select component manufacturers from our database of quality suppliers of CNC machining services. John Hart engineers work closely with these suppliers from the kick-off meeting through to final quality inspection to ensure that both our strict delivery and quality requirements are achieved.

Once all components are delivered to our purpose-built assembly and testing facility, John Hart engineers inspect, assemble and thoroughly test the final product with these key areas of focus:

  • Hydraulic system tested under rated pressures for an extended time to guarantee system integrity
  • CNC fixture tested on 3D measuring machine to ensure required assembly accuracy is achieved
  • Clamping and support elements tested for desired functionality
  • Clamping and support elements set as calculated pressures to suit application
  • Clamping and support elements set to desired sequence by built-in sequencing system
  • CNC ixture tested with clients castings/components for accuracy and rigidity

A final quality check is the undertaken where all CNC fixture components are re-tensioned prior to the fixtures being packed in secure, custom built boxes ready to ship to site.

CNC Programming

workholding fixtures cnc programmingAll John Hart engineers have been trained in advanced CNC programming. This allows us to supply CNC programming services that are not only modular and easy to understand, but include additional features such as:

  • The ability to easily move the entire process to another CNC machine tool if required with minimal production downtime
  • The ability to automatically monitor cutting tool length settings within preset limits to avoid operator related tool collisions in production
  • The ability to quickly and easily modify cutting data in one easy to understand screen
  • The ability to quickly and easily modify positional co-ordinate information in one easy to understand screen

All CNC programs will be compiled at our facility prior to commissioning and will utilize the 3D designs previously created in the design phase to carefully calculate the most efficient tool paths to ensure the best possible productivity.


workholding fixtures commissioningAt the commissioning stage of the project, John Hart engineers will visit the clients site to complete the installation of CNC fixtures, CNC cutting tools and CNC programs to the machines. Our engineers will train the clients’ engineering staff in:

  • Correct and accurate installation and positioning of the CNC fixture as planned in the design stage
  • Plumbing of hydraulic lines to the CNC fixture
  • Connection of pneumatic lines to the CNC fixture
  • Final testing the of CNC fixture for both hydraulic clamping and pneumatic part presence sensing

John Hart engineers will then load the previously prepared CNC machining programs and the appropriate cutting tools to the machine tool.

Process Capability

workholding fixtures process capabilityProcess Capability is the final stage of the project and, when completed, marks the readiness of the CNC machining cell to begin production. With many years of experience with process capability, John Hart engineers will proactively lead the client through this critical process with a goal to complete the required process testing in a most efficient and timely manner.

During this stage, John Hart engineers will work proactively with both the clients’ engineering and quality personnel, and the cutting tool vendors’ support staff to consolidate each individual party into a team with a common directive.

The typical process capability consists of:

  • Proving out of CNC programs
  • Cycle time enhancement
  • Dimensional targeting
  • First part submission to quality engineers for 100% inspection (often known as ISIR)
  • A small batch test run of parts as an initial indication of process capability (often known as a mini CpK)
  • A final capability study (CpK) with a large run of parts under production conditions (clients’ machine operators, full machining rates etc.)
  • Finals reports prepared detailing the capability of the process to begin production

Once all capability testing criteria have been met or exceeded, production can commence.

John Hart engineers will then complete training of the clients operator and maintenance staff and prepare the final documentation of the process for submission to the client. This marks the completion of the project.