CNC Machining
CNCmachining
Precision machining is the joint decision of geometry, tolerance, material and measurement. Eclipse approaches those decisions by reading the drawing, assessing manufacturability and planning the process.
- Processes
- Turning · Milling
- Approach
- Complete in one setup
- Files
- PDF · STEP · DXF
- Status
- Capability under development
01Introduction
Precision comes from the whole set of decisions, not from a single dimension
Making a part precisely depends on reading the drawing, the workholding strategy and the measurement plan — before any machine runs.
In machining, material is removed from a blank in a controlled way with cutting tools. The result is decided by more than the tool and the machine: how the part is held, which surface is the reference, in what order operations are done and what is measured and how carry equal weight.
That is why Eclipse treats a request first as an engineering question, not a manufacturing one: what will this part do, which dimensions are functional and which are not?
Geometry
Rotational or prismatic? Which surfaces can be reached from which direction?
Tolerance and surface
Tight tolerance only on functional dimensions; economical values elsewhere.
Material
Chip behaviour, heat-treatment state and dimensional stability shape the process.
Quantity
Flexibility matters for a prototype, process stability for a series.
02Process selector
Which process fits your part?
Answer two questions to see guidance based on general engineering logic.
Guidance
CNC turning stands out
- When the part is symmetrical about its axis, rotating the workpiece is the most direct route.
- Diameter, thread, groove and hole operations can often be done in the same chucking.
- For off-axis features such as flats, keyways or cross holes, live tooling and a C-axis are considered.
For a prototype flexibility comes first: existing workholding solutions rather than dedicated fixtures, and a process open to design changes.
This guidance is based on general engineering logic; the final decision is made after the technical drawing has been reviewed.
03Comparison
Turning, milling and turn-mill
The three approaches are not rivals; they are the natural answers to different geometries.
| Turning | Milling | Turn-mill (live tooling) | |
|---|---|---|---|
| Typical geometry | Rotational parts | Prismatic parts | Rotational body with off-axis features |
| Motion | The workpiece rotates, the tool moves in X and Z | The tool rotates, the workpiece stays clamped | The workpiece rotates or indexes; live tools do the milling |
| Typical features | Diameter, thread, groove, hole | Pocket, face, slot, hole patterns | Flat, keyway, cross hole, thread |
| Workholding | Collet or chuck | Vice, fixture, zero-point system | Collet or chuck; sub-spindle when needed |
| Setup tendency | One or two chuckings | Depends on the number of faces to reach | Completion in one setup is the aim |
| Typical part families | Shaft, bushing, flange, fitting | Housing, bracket, plate, manifold | Connector, valve part, special shaft |
Turning
- Typical geometry
- Rotational parts
- Motion
- The workpiece rotates, the tool moves in X and Z
- Typical features
- Diameter, thread, groove, hole
- Workholding
- Collet or chuck
- Setup tendency
- One or two chuckings
- Typical part families
- Shaft, bushing, flange, fitting
Milling
- Typical geometry
- Prismatic parts
- Motion
- The tool rotates, the workpiece stays clamped
- Typical features
- Pocket, face, slot, hole patterns
- Workholding
- Vice, fixture, zero-point system
- Setup tendency
- Depends on the number of faces to reach
- Typical part families
- Housing, bracket, plate, manifold
Turn-mill (live tooling)
- Typical geometry
- Rotational body with off-axis features
- Motion
- The workpiece rotates or indexes; live tools do the milling
- Typical features
- Flat, keyway, cross hole, thread
- Workholding
- Collet or chuck; sub-spindle when needed
- Setup tendency
- Completion in one setup is the aim
- Typical part families
- Connector, valve part, special shaft
04Process chain
From technical drawing to shipment
Each step produces the input of the next; a skipped step comes back later as cost.
01
Drawing and requirements
02
Manufacturability review
03
Process plan and CAM strategy
04
Machining
05
Measurement and inspection
06
Packing and shipping
05Material families
Material shapes the machining strategy
Below are material families commonly met in this field and the points that matter when machining them.
- 01
Aluminium alloys
Light and comparatively easy to machine; chip evacuation and built-up edge are managed. Stress and vibration matter on thin-walled parts.
- 02
Carbon and alloy steels
Hardness and heat-treatment state decide the strategy. An allowance for dimensional change after heat treatment may be needed.
- 03
Stainless steels
Work-hardening and heat build-up demand care in tool selection and cutting conditions; chip breaking matters.
- 04
Copper alloys
Brasses usually break chips well; pure copper is soft and gummy. Burr formation is managed.
- 05
Engineering plastics
Heat and flexing call for careful clamping force and cutting conditions; dimensional stability can be affected by moisture and temperature.
- 06
Special and other materials
For materials not listed, quality, documentation and machinability requirements are reviewed together at the request stage.
Material choice and scope are confirmed separately for every project. This list does not imply completed Eclipse references.
06Inspection planning
Measurement starts during planning, not after machining
A good inspection plan puts in writing, before production, which dimension is checked, why and how.
- 01
Identifying critical characteristics
Functional dimensions are read from the drawing; inspection effort focuses on them.
- 02
Datum and measurement strategy
Where each measurement is taken from is decided to match the workholding and operation sequence.
- 03
Choosing the method
The measuring method is chosen to suit the requirement of the characteristic being measured.
- 04
First-article approval
Before moving to the series, the first part is assessed against the drawing.
- 05
Documents
Requirements for inspection reports and material certificates are clarified at the quotation stage.
07Prototype to series
A typical engineering path
Priorities change as quantity grows; the process is re-thought accordingly.
01
Prototype validation
Geometry, workholding and measurement method are validated in small numbers; design changes are cheap.
02
Pilot lot
Process stability and tool life are observed; the control plan and workholding solution are fixed.
03
Series
The approved process is repeated; in-process checks and traceability records continue.
08Design for manufacturability
Six habits that reduce cost and risk
These are general manufacturability principles that do not depend on a particular machine.
- 01
Set inside corner radii by the tool
In milling the inside corner radius should be larger than the tool radius and as consistent as possible; in turning the insert nose radius decides.
- 02
Specify tolerance only on functional dimensions
Putting a tight tolerance on every dimension raises cost and lead time. Highlight the dimensions that decide the function.
- 03
Set the datum strategy early
Which surfaces dimensions are taken from directly affects the clamping sequence and the measurement method.
- 04
Avoid thin walls and ribs
Thin structures flex and vibrate while being machined. Increase wall thickness and rib proportions where possible.
- 05
Define threads and run-out clearance
Show the thread standard, its depth and whether clearance (relief) is left so the tool can run out.
- 06
State edge breaks and surface expectations
The process is planned correctly when edge breaks and surface expectations are stated clearly and only on the surfaces that need them.
09FAQ
Questions before you request a quote
Which file formats can I send?
PDF, STEP (.step / .stp) and DXF files are accepted. PDF is recommended for tolerances and notes and STEP for geometry; DXF suits 2D profiles.
How are tolerances determined?
Tolerances are stated by you on the drawing according to the function of the part. Eclipse confirms whether the stated tolerances are suitable for manufacturing and measurement once the drawing has been reviewed; no general tolerance commitment is given in advance.
Can I request a prototype or a series?
Both prototype and series requests are assessed. Quantity, delivery plan and documentation requirements are clarified at the quotation stage.
Which materials are handled?
Material scope is confirmed per project. Simply state the material type and quality requirements in your request; suitability is answered after the drawing has been reviewed.
What about heat treatment or surface coating?
Supplementary operations are assessed separately within the project. If needed, state them in your request; the operation sequence and dimensional allowances become part of the planning.
How is a quotation prepared?
The drawing, material and quantity are reviewed; missing information is asked for; once the scope is clear a quotation is prepared. The response time depends on the scope of the request.
Related pages
Capability status
Eclipse Engineering is building its precision-manufacturing capabilities step by step. The manufacturing areas described on this page are target capability areas within the company's investment programme; equipment, capacity, material scope, tolerance class and lead time are confirmed separately for each project once the technical drawing has been reviewed.
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