Hydraulic clamping
Consistent clamping force across every cycle, with sequenced clamping for parts that distort. Suited to medium and high volume where repeatability decides scrap rate.
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03 / Workholding
Custom CNC fixtures, designed around the cost of the part
Liuzhou Dongben Machinery Equipment Co., Ltd. designs and builds CNC workholding for production machining: hydraulic, pneumatic and manual fixtures, modular tombstone set-ups, and dedicated fixtures for aluminium and cast iron parts. Scope runs from drawing and DFM review through fixture build, prove-out and first-article inspection.
Types
Five workholding approaches we build
The choice is driven by batch size, part geometry, and how much of the cycle you can remove from the operator.
Pneumatic clamping
Faster actuation and simpler shop-air installation than hydraulics, with lower force. A good fit for aluminium parts with light cutting loads.
Manual and quick-release
For low volume and high mix. Well-designed manual fixturing with fixed stops and interchangeable jaws often beats an over-automated cell.
Modular tombstone
Four or more faces on one pallet, so the machine cuts while the operator loads. The standard route to unattended running on a horizontal machining centre.
Dedicated fixtures
Built for one part family and one process. Highest performance per part, lowest flexibility — justified only where annual volume carries the tooling cost.
What we do not do
We do not sell standard catalogue clamps as a custom fixture, and we do not quote a fixture that cannot pay back inside your batch size. If the arithmetic fails, we say so before you spend.
Design inputs
What we need to quote a fixture
Missing any of these is the usual reason a fixture quotation stalls. Send what you have and we will tell you what is still open.
- Geometry2D drawing in PDF plus a 3D STEP file. The STEP file matters more than the print for fixture design.
- MaterialMaterial grade and blank form — billet, casting or forging. Castings bring datum and stock variation into the design.
- MachineMachine model and control, table or pallet size, spindle taper, and available coolant-through capability.
- VolumeBatch size and annual volume. This single number decides hydraulic versus manual more than any other input.
- QualityCritical dimensions, tolerances and surface finish, and which surfaces are datum for the next operation.
- ConstraintsOperator access, crane or robot handling, chip evacuation, coolant compatibility, and whether the fixture must survive a wash station.
- TargetCurrent cycle time and the cost per part you are trying to reach. Without a target there is no way to judge the design.
Cost model
Four levers, quantified before quotation
Lead and unload
Manual clamping on a part with a 90-second cycle can consume 20–30 seconds of operator time. Sequenced hydraulic clamping removes most of it from the cycle and moves it to load-while-cut.
Stability at higher parameters
Chatter is a workholding problem more often than a tool problem. A rigid, well-supported fixture lets you use the feed and speed the tool was designed for, which shortens the cycle and extends tool life at the same time.
Scrap and rework
An inconsistent datum produces a distribution instead of a tolerance. Fixed stops and repeatable clamping force are what convert a stretched capability index into a comfortable one.
Unattended capacity
A tombstone or pallet-pool set-up is what lets a machine run through the second shift. The saving is not cycle time — it is machine hours you did not have to buy.
We express each of these as a number per part, against your machine rate, before you place an order.
Process
From drawing to first-article
Drawing and DFM review
Datum strategy, wall thickness, deformation risk and chip evacuation, read before any concept is proposed.
Concept and clamping scheme
Locating scheme, clamping force and sequence, fixture concept drawing, and the cost impact stated per part.
Build
Fixture manufacturing, hydraulic and pneumatic circuit assembly, and tooling selection matched to the material.
Prove-out
Trial cut on your machine, first-article inspection, and parameter handover documented for your operators.
Send a drawing. Get a clamping scheme and a cost per part.
2D PDF plus 3D STEP, material, batch size and machine model is enough to start.