The most important part of your installation is the linear scales. These are what provide the positional feedback and are critical for system accuracy. The different types all have different modes of mounting, some of which are easier and more accommodating than others. At EMS-I we have a number of different scale options for all machine types from full sized industrial machines through to small table-top systems. All of our scales carry a 2-year warranty and we continually strive to provide the best products at the best value for money.

WE HAVE SCALES COMPATIBLE WITH MOST COMPETITORS DRO’s

EMS (International) Ltd. , Unit 7, Kingsley Business Park, Kibworth Beauchamp, Leicestershire LE8 0LE, England

Tel. +44 (0) 116 279 3035  : Fax. +44 (0) 116 227 1307 : Email. info@ems-i.co.uk


Registered office: The Stables, Church Walk, Daventry, Northamptionshire NN11 4BL England

Registered in England and Wales No. 06648286

© EMS (International) Ltd. All Rights Reserved

Optical Scales

Strengths

Weaknesses

Applications

These are the most common types of scales still fitted on the vast majority of machine tools today. They essentially have a glass grating inside and uses light to work.

  • Proven technology
  • Can be low cost (imports)
  • Can have fine resolutions and accuracy
  • Installation generally well understood
  • Performance scales ideal for CNC


  • Available only in standard lengths
  • Can not be 'made-to-fit' during installation
  • Contamination issues (from coolant)
  • Lengths over 1m get expensive
  • Rarely available over 3m travel
  • Mid sized machine tools
  • Precision inspection systems
  • CNC

Scale Types

There are many types of scales that have and can be used with machine tools. Each have their own characteristics which are discussed below. The most common are optical scales as these have been around the longest and have been the focus of development for many budget companies and Internet suppliers. This however, does not make them the best option for many applications, especially on smaller machines. Why not call us to discuss your application and we would be happy to discuss the options available.

Things to consider:

Enclosed Magnetic Scales

Strengths

Weaknesses

Applications

These are becoming much more popular as the technology gets better and better. These look like, and install, just like optical scales and in many cases can be a direct replacement.

  • Highly robust coolant proof (IP67)
  • Looks and install like glass scales
  • Cheaper than glass over 1100mm
  • Can be be highly accurate
  • Can have high resolutions
  • Can be long lengths
  • More expensive than 'budget' glass
  • Available only in standard lengths
  • Can not be 'Cut-to-Fit'
  • Mid to large machine tools
  • Mid-level Inspection systems
  • CNC

Spar Mounted Magnetic Scales

Strengths

Weaknesses

Applications

These are great on a large variety of machines due to the diversity of spars that are available. The scales can be  almost any length up to 60m or more! The reader-head is separate from the scale which allows greater flexibility any ease of service should it ever be necessary.

  • Highly robust coolant proof (IP67)
  • Easy to install
  • Can be 'cut-to-fit'
  • Broad range of accuracies & resolutions
  • Can be inexpensive
  • Easier to service
  • Non-contact
  • Can be ideal for smaller machines
  • Incremental, distance-coded and absolute options are available
  • High speed applications
  • Different fitting methodology to glass
  • Not as accurate as optical in high-precision applications for CNC and inspection (but improving all the time!)
  • Mid to large machine tools
  • Inspection systems
  • CNC
  • Press-brake and automation

Magnetic Tape Scales

Strengths

Weaknesses

Applications

Tape systems can be cut to any desired length and are very compact in size at just 10mm x 1.6mm thick. The tape is magnetically coded and is the same as used in the enclosed and spar mounted options, and is protected by a non-magnetic stainless steel protection cover.The reader-head is separate from the scale which allows greater flexibility any ease of service should it ever be necessary.

  • Highly robust coolant proof (IP67 or IP68)
  • Can be 'cut-to-fit'
  • Can fit in very small spaces
  • Broad range of accuracies & resolutions
  • Least expensive option
  • Easier to service
  • Can be ideal for smaller machines
  • Ideal for those on a tight budget
  • Incremental, distance-coded and absolute options
  • High speed applications
  • Non-contact
  • Requires more work to fit
  • Limited mounting kits available
  • Requires a good, oil free, smooth mounting surface for mounting
  • Mid to large machine tools
  • Table-top and smaller machines
  • Inspection systems
  • CNC
  • Linear motors
  • Pick and place machines
  • Transfer lines

Inductive Scales

Strengths

Weaknesses

Applications

These are best known as 'Ball-scales' but there are other types. These are highly robust to contamination and are available in a variety of sizes and shapes.

EMS-I do not provide these scales but we can provide a replacement Ball-scale DRO as a service replacement: CLICK HERE

  • Highly robust coolant proof (IP67)
  • Incremental, distance-coded and absolute options
  • Strong brand name
  • Different fitting methodology to glass
  • Only made in standard lengths
  • Not as accurate as optical in high-precision applications for CNC and inspection
  • Available only in standard lengths
  • Mounting issues over 1m
  • Very expensive
  • Mid to large machine tools
  • Press-brake

Capacitive Scales

Strengths

Weaknesses

Applications

These scales are generally supplied as self-contained systems as no main stream DRO supports their interface. Not really suited for machine tool they are a lower cost alternative to magnetic scales for non-critical applications such as table saws, wood working etc.

To see our range of capacitive scales: CLICK HERE

  • Generally robust
  • Can be 'cut-to-fit'
  • Can fit in very small spaces
  • Least expensive option
  • Ideal for those on a tight budget
  • Normally battery powered
  • Can be pseudo absolute as are most commonly battery powered
  • Low accuracy, depends on length
  • Limited resolution
  • Limited in length (less than 1000mm)
  • Table saws
  • Simple Quill scales
  • Routers
  • Simple measurement
  • Woodworking

So what scale is best?

This really depends on your machine, the work you are doing and the level of performance required. Our experience has shown that for some machines, such as Colchester and Harrison lathes, there is no one right answer. Here our most popular systems use our S1, spar mounted magnetic, on the cross and a GS120 optical scale for the bed. This provides the best fit on the cross-slide, in what is a tight space, with coolant robustness combined with the economy of an optical on the Z-axis. For a smaller machine like a SIEG mill or Myford lathe it may be best to select the tape option with the incredibly small EMC14 reader-head. With such a small size it makes for a cost effective and yet high performance solution that is in keeping with the machine. Trying to fit an optical scale would not be easy, look cumbersome and you would almost certainly loose some of what is already small travels. We now offer EMC14 kits specifically for these smaller machines.

REVIEW SCALE OPTIONS REVIEW SCALE OPTIONS

If in any doubt why not give us a call for a no obligation, friendly chat and we will be happy to discuss your application and the various options with you.

EMC14 Mini reader-head

Just 36 x 11 x 14mm

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