How to Choose a CNC Chip Removal System

Start with five things: chip form, chip volume, workpiece material, coolant requirements and unattended runtime.

Hinge belt: mixed and medium-to-large chips.
Scraper: settled fines, short swarf and sludge.
Magnetic conveyor: ferrous chips with enough magnetic response.
Auger: moderate amounts of short chips where space is tight.
Filtration conveyor: jobs where fine particles also need to come out of the recirculating coolant.

Machine size alone will not tell you which system to buy. Look at the chips the process really produces. The conveyor needs to survive the highest sustained chip load, while the bin needs enough room for everything produced before the next planned emptying.

Quick Selection Guide

Machining Condition	System to Evaluate First	Main Risk to Check
Mixed short and medium chips	Hinge-belt conveyor	Chip load and coolant carryout
Long steel or stainless chips	Heavy-duty hinge belt	Tangling and bridging
Fine settled chips or swarf	Scraper conveyor	Particle loading and abrasion
Fine magnetic ferrous chips	Magnetic conveyor	Actual magnetic response
High-volume aluminum chips	Hinge belt or chip/filtration system	Large loose-chip volume and coolant return
Compact machine with short chips	Auger	Wrapping by long chips
Fine particles in coolant	Filtration conveyor	Filtration level and coolant flow
Unattended machining	Automated conveyor with suitable coolant management	Bin capacity, jams, filter loading, and alarms

Start with the Worst Chip Form

Two machines cutting the same material can make completely different chips. Tool geometry, feed, depth of cut, operation and chip breaking all change the result.

Look at what is actually coming out of the machine:

• short broken chips
• curled chips
• long strings
• nested or bird's-nest chips
• fine particles
• grinding swarf or sludge

Long chips can bridge an opening or wind around an auger. Very fine particles may pass straight through a basic conveyor and stay in the coolant circuit.

Metalworking fluids cool and lubricate the cut and also help carry chips away from tools and parts. NIOSH identifies inhalation of metalworking-fluid aerosols and skin contact as exposure routes.^[1]

Photos are surprisingly useful here. Add real chip photos to the RFQ. They show length, nesting, fines and packing behavior far better than a note saying “medium steel chips.”

Measure Chip Volume Before Sizing

Axis travel does not tell you how many chips a machine makes. The LJ-855 vertical machining center, for example, has 800 mm X travel, 550 mm Y travel and 550 mm Z travel. Actual chip output still depends on the amount of material being removed.

Collect loose chips during a representative production cycle and calculate:

Bulk chip rate = collected loose-chip volume ÷ collection time

Use the highest sustained rate from your normal production mix when checking conveyor capacity. If the material, tooling or cutting strategy changes enough to alter chip formation, measure it again.

The conveyor and the bin should not be sized from the same number. The conveyor has to handle the heavy chip-producing parts of the cycle. The bin has to hold the total loose-chip volume produced before it is emptied.

For unattended machining:

Required bin volume = total loose-chip volume produced during the unattended production window

If several jobs run before anyone comes back to the machine, add the chip volume from all of them.

Use Volume, Not Scrap Weight Alone

Loose chips are full of empty space. A bin can fill up long before it reaches its structural weight limit.

NIST lists the density of aluminum at about 2.699 g/cm³ and iron at about 7.874 g/cm³.^[2]

Loose-chip bulk density is much lower than solid-material density and changes with chip shape. Long, curled aluminum chips are a good example: they can fill a bin quickly while the total scrap weight is still fairly low.

For aluminum-heavy work, track:

• loose-chip volume per cycle or hour
• chip packing behavior
• usable bin volume
• coolant carryout
• coolant-return capacity
• fine-particle load

Choose the Conveyor Type

Hinge-Belt Conveyor

A hinge belt is a sensible starting point for mixed, medium and larger broken chips, especially in shops where materials and jobs change often.

The Dual Tool Magazine Vertical Machining Center includes a chip-removal system among its configuration options. Pick the conveyor around the actual chip load and coolant circuit, not just the machine model.

A plain hinge-belt conveyor is not a fine filter. Without additional filtration, very small suspended particles can stay in the coolant.

Scraper Conveyor

A scraper pulls settled material along the bottom of the tank or conveyor housing.

It is worth considering for:

• fine settled chips
• short swarf
• cast-iron fines
• abrasive particles
• grinding sludge

Large nests of long chips can clog a scraper system. If the process makes both large chips and a lot of fines, separate conveying and filtration stages may work better.

Magnetic Conveyor

A magnetic conveyor works only when the chips respond strongly enough to magnetic attraction.

It can be useful for small ferrous chips and fines. Aluminum, copper and brass are not suitable for magnetic conveying.

Stainless steel needs a little more care. Different grades and conditions do not all behave the same way magnetically, so test the actual chips before specifying a magnetic-only system.

Chip Auger

An auger is compact and works well with moderate quantities of short chips.

Long, stringy chips are the problem. They can wrap around the screw or bridge the chip path. Some machines use an auger only to push chips toward a larger main conveyor instead of asking it to handle the entire evacuation route.

Filtration Conveyor

Use filtration when getting the visible chips out is not enough and fine particles also need to be removed from the recirculating coolant.

Do not simply choose the smallest micron rating you can find. Match filtration to the coolant pump, nozzles, through-spindle coolant system, tooling and actual machining process.

Match Filtration to the Coolant System

OSHA notes that metalworking-fluid systems are exposed to chips, fines, tramp oil and other contaminants. Its guidance calls for effective filtration, regular debris removal and maintenance of filtration systems.^[3]

Give the supplier:

• coolant type
• normal coolant flow
• maximum coolant flow
• pump pressure
• tank capacity
• through-spindle coolant requirements
• maximum particle size allowed by the coolant circuit

The return and filtration system needs to cope with maximum required coolant flow under real operating conditions. Otherwise, you can end up with a conveyor that moves chips perfectly while the coolant return is still the bottleneck.

Finer filtration also means more material is being captured. Filter area, cleaning method, sludge load and service access all need to be looked at alongside the micron rating.

Check Coolant Carryout

If chips leave the conveyor before they have time to drain, a lot of coolant can end up in the scrap bin.

Look at:

• chip geometry
• conveyor incline
• drainage time
• belt speed
• conveyor cycle
• coolant viscosity

Keep an eye on how much coolant you add back to the machine and look inside the chip bin. If there is always free coolant sitting in the bin, drainage time, conveyor cycling or general chip handling probably needs attention.

Plan for Unattended Machining

During an unattended run, a bird's nest of chips, a full bin or a loaded filter can stop the machine long before the operator comes back.

• total chip volume before the next operator visit
• bin-full detection where available
• conveyor overload detection
• jam detection
• automatic reverse where available
• coolant-level monitoring
• filter condition or pressure monitoring where applicable
• CNC alarm integration

Automatic reverse is useful, but it cannot rescue a conveyor that is simply too small for the real chip load.

Account for Machine Orientation

Machine layout changes how easily chips reach the conveyor.

On a VMC, chips can sit on the workpiece, fixture, table or inside a deep pocket until coolant or air pushes them toward the collection area.

On a heavy-duty horizontal machining center, gravity can help chips fall away from the cutting zone. AsiaTools also covers this in its guide to horizontal machining centers and chip evacuation.

Look for dead areas before buying: sump position, wash-down direction, conveyor inlet, chip slopes and pockets where material can build up before reaching the conveyor.

Use Chip Blowers for Local Cleaning

A CNC chip blower can clear chips off the workpiece or fixture and move them toward the machine's normal collection path. It does not replace the conveyor, sump or coolant-return system.

For manual compressed-air cleaning, OSHA 29 CFR 1910.242(b) requires cleaning air to be reduced to less than 30 psi and used with effective chip guarding and personal protective equipment.^[4]

A blow gun chip guarding shield can be part of that guarding setup, but it does not replace the pressure and PPE requirements.

Measure Installation and Service Space

Before ordering, measure:

• conveyor inlet size
• tank opening
• overall conveyor width and length
• incline geometry
• discharge height
• bin dimensions
• electrical connection location
• coolant-return location
• conveyor removal direction

Do not confuse installed footprint with service space. A conveyor can fit perfectly beside the machine and still be impossible to pull out for belt work, motor access or tank cleaning.

Check Maintenance Before Buying

See how easily you can get to:

• tank and sump
• belt or chain
• scraper flights
• auger
• filter elements or screens
• coolant-return channels
• pumps
• sensors

With abrasive fines, also look at wear on floors, guides, hinges, scraper parts, sprockets and seals.

Ask which wear items can be changed without pulling out the whole system. Spare-part availability matters too, especially if the machine is expected to stay in service for many years.

Plan Safe Jam Clearing

A chip jam can put an operator close to sharp swarf, moving parts, electrical energy and stored mechanical energy.

OSHA 29 CFR 1910.147 covers servicing and maintenance where unexpected energization, startup or stored energy could cause injury. Its definition of servicing includes cleaning and unjamming when workers are exposed to those hazards.^[5]

Some normal-production servicing situations have specific exceptions and alternative protective measures under the standard, so the site's own energy-control procedure should define how each jam is cleared.

• guarding
• accessible energy-isolation points
• overload protection
• jam detection
• safe access for cleaning
• documented maintenance procedures

What to Include in a Chip Conveyor RFQ

Category	Information to Provide
Machine	CNC type, model, tank dimensions, conveyor opening, available space
Process	Milling, drilling, turning, grinding, or combined operations
Material	Current grades and expected future material mix
Chips	Photos, typical form, worst form, measured bulk volume
Coolant	Type, normal and maximum flow, pressure, tank capacity, filtration requirement
Production	Cycle information, shifts per day, maximum unattended period
Discharge	Required height, bin dimensions, emptying schedule
Installation	Available footprint, service clearance, electrical requirements

“Chip conveyor for a VMC” is too vague for reliable sizing. Give the supplier real chip, coolant, production and installation data.

Common Selection Errors

• Sizing by machine dimensions: chip output follows the cutting process, not axis travel.
• Sizing by material name: the same material can make short broken chips or long tangled strings.
• Using only average chip output: the conveyor also has to cope with sustained high-load parts of the cycle.
• Using peak rate to size the bin: the bin needs enough room for all chips produced before the next emptying.
• Ignoring fines: visible chips may be gone while fine particles are still circulating in the coolant.
• Choosing the finest filter available: filtration should match what the coolant circuit really needs.
• Ignoring coolant flow: poor return capacity can cause trouble even when the conveyor itself is large enough.
• Ignoring future materials: a magnetic-only system can become a problem if non-ferrous work is added later.
• Ignoring service clearance: the space needed to install the conveyor is not always enough to service or remove it.
• Treating a chip blower as the main removal system: a blower moves chips locally; it does not carry them out of the machine.

Five-Step Selection Method

1. Find the hardest chip to handle. Look for long strings, fines, abrasive material and large volumes of loose chips.
2. Measure real chip output. Record bulk volume during representative production.
3. Size the conveyor and bin separately. Use sustained high chip load for the conveyor and total production between emptying events for the bin.
4. Define the coolant requirement. Record flow, pressure, filtration and through-spindle coolant needs.
5. Check installation and service access. Confirm the inlet, discharge point, bin position, electrical connection and removal space.

FAQ

What is the best chip conveyor for a CNC machining center?

For mixed general machining, a hinge belt is a reasonable place to start. Scrapers suit settled fines, magnetic conveyors suit sufficiently magnetic ferrous chips, and augers work with moderate short-chip loads. Add filtration when fine particles also need to be removed from the coolant.

How do I calculate chip conveyor capacity?

Measure the highest sustained loose-chip volume produced during real machining and express it as volume per unit time. The conveyor has to move that load without constant accumulation or jamming.

How do I size the chip bin?

Add up the total loose-chip volume made between planned emptying events. For unattended work, include every job scheduled before the next operator visit.

Should I size by chip weight or volume?

Use both, but volume often decides the bin size because loose chips contain a lot of air. Check the structural weight limit separately.

Does every CNC machine need fine coolant filtration?

No. The filtration level should come from the pump, coolant passages, nozzles, through-spindle coolant system, tooling and machining process.

Can a magnetic conveyor remove aluminum chips?

No. Aluminum does not have the ferromagnetic response needed by a conventional magnetic chip conveyor.

Is a scraper conveyor suitable for cast-iron chips?

It can be, especially when the process creates fine particles that settle in the coolant. Depending on the actual chip and coolant condition, magnetic separation or extra filtration may also be useful.

Can a CNC chip blower replace a conveyor?

No. A blower clears chips from local surfaces. The conveyor still has to carry them out of the machine.

Conclusion

Base the choice on real chip shape and measured production data.

• Mixed or larger broken chips → hinge belt
• Settled fines and sludge → scraper
• Magnetic ferrous fines → magnetic conveyor
• Moderate short-chip loads → auger
• Fine contamination in coolant → filtration conveyor

Size the conveyor for the highest sustained chip load and the bin for everything produced before the next emptying. After that, check coolant flow, filtration, discharge height, service access and the length of any unattended run.