Quick change tooling solutions

Productivity factors

Productivity is the number of parts produced per shift or week. Understanding where the biggest improvements can be made is vital before considering which solutions to implement. There are two important factors to take into account:

1. Metal cutting efficiency – this can be measured in terms of metal removal rate (cm³/min (in³/min)) for any operation
2. Machine utilization – this can be measured in percentage time the green light on the machine is on (the ability to maintain continuous production for a long period)

Machine utilization is very much linked to the machine configuration and options. This needs to be considered prior to new machine investment to make sure the best technologies are implemented.

Typical time killers in factories reducing machine utilization are:

• Batch set-up
• Measuring the component in the machine
• Tool setting in the machine
• Coolant pipe setting
• Changing worn tools
• Chip removal around tools or blocked conveyors
• Component change over

How tools are loaded and measured has a huge impact on the machine utilization – the best comparison is motor racing and minimizing the time the car is in the pit stop and this is why minimizing any machine stoppages is so important.

Through coolant delivery ensures that the full capabilities of the machine are harnessed with optimized cutting units to reduce setting and deliver the coolant with maximum impact to provide chip control.

Quick change tooling benefits

CNC lathes and sliding head machines have fast tool indexing but typically have a lower utilization than machining centres due to the tool change and set-up time. Manual quick change is utilized where there is no automatic tool change (ATC) in the machine ensuring the green light on the machine is on for longer. The benefits of using quick change are many.

Reduced batch change over time using tool kits

Changing from one style of tool to another is dramatically reduced.

• Turning tool holders from 5–10 mins down to 30 seconds
• Boring bars takes a little bit longer time than shank tools because of centre height setting and coolant plumbing
• The advantages with quick change tooling is even more in combination with long boring bars. Boring bars up to 10×D can be changed with 2 μm (78.7 μinch) accuracy in less than 1 minute
• Driven tools from 5–20 mins down to 30 seconds. Normal driven tools holders are ER or face milling. ER is limited to end mills with maximum diameter 25 mm (1 inch) which means two separate driven holders. With Coromant Capto® the same unit covers all applications

Increased number of tool positions

Increased number of tool positions with double tool holders allow the block to be used for both internal and internal operations.

Turning centres with driven tool holders often have limited space. Using double clamping units allows either sister tooling or increased variety of tools, thereby reducing tool change requirement for a wider range of components. Double clamping units can be used when the machine has Y-axis, half turret or sub-spindle.

Reduce worn tool indexing time

Driven tool holders: Every time a solid carbide tool is changed the tool offset needs to be re-calibrated. With indexable mills/drills multiple inserts need to be changed. Using sister tool and change the cutter outside the machine is much quicker.

Static tool holders: For single inserts with good accessibility it can go as quick to change directly in the machine. However, being able to remove the tool ensures improved maintenance of the tool, correct mounting and no unexpected stops due to needs for spare part purchases.

Eliminate coolant pipe setting

This varies from application to application but when operators are setting the coolant pipe direction it normally takes two to three attempts to get it right – red light on! Poor chip control often then knocks the pipe which means that setting is quite a regular occurrence.

Quicker production start up

By eliminating either "first test component" or "measuring cuts" the production rate is increased and scrap reduced. Calculated through the year if quick change was used the number of additional components produced and reduced scrap rate is significant.

• First test component for higher volume production: The first component of every tool change is often scrapped and the tool change time needs to be considered as; change tool (keep old offset), cut complete part, measure finished component and adjust offset
• Measuring cuts for low/medium volume production: Taking a measuring cut with backed off offset ensures that the component is not scrapped but can take longer time. Tool change time needs to be considered as; change tool, back off offset, cut, measure and adjust offset

Ergonomic and easy to use for the operator

Quick change has many benefits for the operator, for example, changing tools outside the machine reduces accidents, errors and searching for dropped parts. It is also easy to standardize in all machine types.

Quick change in sliding head machines

Quick setting of boring bars

Setting of boring bars in the turret takes longer time compared to a shank tool due to length/centre height positioning as well as plumbing through coolant into the back of the tool.

Sleeves, such as EasyFix, provides a fast and simple way of achieving correct centre height when mounting cylindrical boring bars into the machine. A spring plunger solution mounted in the sleeve clicks easily into a groove in the bar to guarantee the correct centre height ensuring consistently high quality parts.

The sleeve is available in a metallic sealed version for high pressure coolant as well as the original with a slot filled with a silicon sealer for low coolant pressures.

Quick change with Coromant Capto®

Coromant Capto® is a modular quick change tooling concept which ensures that both machine utilization and metal cutting efficiency are maximized. Below are some of the key benefits of Coromant Capto®.

Segment clamping

The camshaft activated drawbar is used for both locking the coupling, with segment clamping, and for pushing out the cutting head. Only a turn is needed to lock and unlock the manual clamping unit. The camshaft has a self-locking angle and will not open during machining.

Repeatability

The high precision of the coupling and its self-centring design ensures a repeatable accuracy less than ±2 microns in the x, y and z-axis for one and the same cutting unit in the same female receiver.

This allows pre-setting outside the machine for high batch production or tool kits for batch change over. Both eliminating measuring cuts allowing faster start up and reduced scrap rates.

Coromant Capto® quick change calculator

Increased stability

Stability is measured in terms of bending stiffness and torque transmission. The key features providing the superior stability are:

• Face and taper contact: Resisting bending moments and providing positional accuracy
• Polygon coupling: The large contact area transmits torque without any loose parts such as pins or keys. The torque load is spread symmetrically without peaks irrespective of direction with the polygon shape self-centring for accurate tip seat centre height
• High clamping force: The segment clamping generates high clamping forces ensuring a press fit and a two face contact resisting the bending moment generated during cutting

Read more about torque transmission and bending stiffness

Clamping unit range

CDI

Dovetail VDI-DIN 69881

Coromant Capto® clamping units for bolt on interfaces (CBI)

Automatic tool change in turning centres

Automatic tool change in turning centres is a game-changing solution that enables unmanned production and maximizes output.

Coromant Capto® disc interface (CDI)

Non standard clamping units – clamping unit sets

Clamping unit sets are used to make clamping units to specific requirements. These are used commonly for tool blocks for vertical lathes, double units or retrofitting quick change onto existing turrets.

The clamping set sleeves are available in different forms depending upon the application.

Styles of machining specific clamping units

External – OD turning

Internal – ID turning/drilling

Driven