ENC 250™ SINGLE SECTION REFERENCE MANUAL Acu-Rite Companies Inc.
ENC 250™ Table of Contents SINGLE SECTION Page Introduction .............................................................................. 2 Page Electrical Shielding ................................................................ 12 Mounting Preparation ............................................................. 3 Mounting Information ............................................................. 4 Troubleshooting .....................................................................
Introduction / Supplied Items The ENC 250 linear encoder provides the accuracy and reliability of an Acu-Rite Companies Inc. measuring system with digital output. Features and options include: • Resolution of [.0002in.] 5µm • Accuracy grade of +/-15µm/M • [2 ft.] .61m armor cable and extension cables up to a maximum of [75 ft.] 22.86m for a VRO; [35 ft.] 10.67m for a DRO • Mounting hardware • Brackets and accessories Contact your Authorized Distributor for a complete list of other products and accessories.
ENC 250™ Mounting Preparation SINGLE SECTION Please follow these preparation guide lines. Measuring length ... • • • • Understand your mounting requirements. Mount with lip seals down and away from the work area. Brackets should be kept as short as possible and rigid. Surfaces must be in good condition, clean, and free of dirt. Remove paint from machined mounting surfaces. Alignment brackets must only be removed as • instructed. [1.0”] 25mm [2.8”] 71.1mm “L” “L” = Measuring length + [2.0”] 50.
ENC 250™ Mounting Information SINGLE SECTION End of scale clearance requirements Use this information to plan your Linear Encoder installation. [1.0] 25mm • Mount the linear encoders close to machine guide ways to ensure system accuracy. • Space between reading head casting and mounting bracket or surface must not exceed [.188”] 4.7mm. [5.0] 127mm [5.0] 127mm • [1.0] 25mm of clearance is required above the scale case top surface for access to the expansion cover fasteners.
ENC 250™ Encoder Dimensions SINGLE SECTION [.83] 21.0 [3.2] 81.3 [.37] 9.4 5 Acu-Rite Companies Inc.
Mounting Requirements ENC 250™ A variety of mounting conditons can be accommodated. SINGLE SECTION Reading head mounting plate ... • The machine configuration determimes the brackets required to install the encoder. • Two typical mounting conditions are shown; reading head mounting plate, and a three piece combination assembly for mounting the reading head to the machine. • The [8-32] 4mm SHCS for mounting the reading head is a standard low head style fastener, supplied with the mounting hardware.
ENC 250™ Encoder Installation Procedure SINGLE SECTION The stud tool is used temporarily to support the encoder while locating the mounting holes These steps apply to all mounting conditions. Although this may not pictorially represent your application, your installation procedure should follow these steps. • Adjust drill depths and fastener lengths as required. • When instructed on page 10, adjust the leveling set screws as follows: 1. Insert, but do not tighten the [8-32] 4mm reading head screws. 2.
Encoder Installation Procedure ENC 250™ Align to within [.012”] .3mm TIR to the axis travel measuring over each hole location SINGLE SECTION Align to within [.012”] .3mm TIR to the axis travel measuring over each hole location Axis Travel Axis Travel Starting hole [1/4-20 x 1-1/4”] M6 x 30mm SHCS & M6 flat washer [1/4-20 x 1-1/4”] M6 x 30mm SHCS & M6 flat washer • Starting at the right end, align the top of the scale case, and transfer punch each remaining hole location.
ENC 250™ Encoder Installation Procedure SINGLE SECTION Align to within [.012”] .3mm TIR to the axis travel measuring over each hole location Axis Travel Example: high point Loosen next two fasteners • Loosen the next two fasteners to the right of the high point. • Move indicator to the first hole location, insert two M3 x 25mm SHSS (leveling set screws). • Use the leveling screws to align the face to within [.012”] .3mm to the high point along the axis travel and secure the fastener.
Encoder Installation Procedure ENC 250™ Universal brackets are available from ACU-RITE for mounting the reading head. SENC 150 & SENC 250 encoders use most of the same reading head brackets. SINGLE SECTION Slide brackets back away from the reading head and cable Custom designed brackets by the installer should be solid, rigidly assembled components, attached to the machine with [1/4-20] M6 fasteners minimum.
ENC 250™ Encoder Installation Procedure SINGLE SECTION End Cap Remove plastic plug Compession sleeve Thumb screw Washer Thumb screw • Tighten the screw until the readout display reads approximately .05mm. • Back off the screw until the display stops changing. • Reset readout to zero and repeat the procedure two more times. This relaxes the tape before setting the tension. • Remove red plastic plug. • Insert the thumb screw through the washer, compression sleeve, and into the end cap hole.
ENC 250™ Encoder Installation Procedure SINGLE SECTION Electrical shielding ... • Connect a ground wire from the terminal on the back of the readout to the machine or earth ground. • Attach a ground wire from the machine to a solid earth ground. • With the encoder attached to the cable connected to the readout, check shielding by measuring resistance between connector housing and scale unit. Desired value: 1 ohm max.
ENC 250™ Trouble Shooting SINGLE SECTION If you experience difficulties with your installation, do the following to determine the problem. Follow these steps to determine the cause of your system difficulties: Checking the Readout • Confirm that your bracketry and installation does not interfere with other machine structures through the entire length of the linear encoder travel. • Check for loose fasteners.
Mechanical Specifications ENC 250™ Mechanical Specifications Digital Resolution 5µm [0.0002 in.] Grating pitch 100µm [0.00393 in] Scale medium Reflective Metal Tape Accuracy ± 15µm/M [0.00018 in/ft] Max. slew speed Force required to move reading head Operating Environment: Temperature Relative Humidity Storage Environment: Temperature Humidity Weight w/cable 1 M/sec [40 in/sec.] ± 3.3 Newtons [0.
ENC 250™ Specifications SINGLE SECTION Output Signals and Pin-Outs Digital Differential Pin 1 Pin 2 Pin 3 Pin 4 Pin 5 Pin 6 Pin 7 Pin 8 Pin 9 N/C Green Yellow Blue Red White Brown Pink Gray N/C Channel A+ Channel A- Channel B+ Channel B- Ground Vcc, + 5.1 ± 0.1 VDC Channel R+ Channel R- 1 5 6 15 9 Acu-Rite Companies Inc.
Electrical Specifications ENC 250™ Digital Parameter Output Signals IOH=(High level output current) = 20mA VOH=(High level output voltage) >2.5Vdc 0° 360° 1 Channel A+ 0 Channel A- 1 0 Channel R+ Channel R90° 1 0 1 Channel B0 Channel B+ Incremental signals 1 0 1 0 1 Count (Phased) IOL=(Low level output current) = 20mA VOL=(Low level output voltage) < 0.5Vdc Square-wave voltage signals.
ENC 250™ Warranty SINGLE SECTION 3 Year Warranty ... Acu-Rite Companies Inc. readouts and precision scales are warranted to the end user against defects in material and workmanship, and against any damage that occurs to the product within three (3) years from the original purchase date. Acu-Rite Companies Inc. will, at its discretion and expense, repair or replace the returned item or any of the item’s component(s) as long as Acu-Rite Companies Inc.
Tool Requirements s l o o T ENC 250™ You will need the following tools to complete the installation: • • • • • • • • • • • • • • • • • • 0.001” Dial Indicator with Magnetic Base English Hex Wrench Set Metric Hex Wrench Set Dial Calipers Feeler Gage Hand Drill Hand Tap Taps(English): 1/4-20 UNC & #8-32 UNC Taps(Metric): M6, M4 Drills(English): #7 (.201”), #29 (.136”), N (.302”) Drills(Metric): 5mm, 3.3mm, 7.7mm Reamer(English): .
Acu-Rite Companies Inc. IS AN ISO 9001 CERTIFIED MANUF ACTURER MANUFACTURER One Precision Way • Jamestown, NY 14701 Acu-Rite Companies Inc.
