Congratulations. You’ve just purchased that newpiece of equipment to help you improve produc-tivity, enhance the capabilities of your techniciansand generate more revenue for your shop. Buthave you given any thought to the equipment re-

quired to maintain your new investment? Neglecting cali-bration and maintenance programs canturn your investment into a waste of money.

This report covers a few of the impor-tant calibration and maintenance consid-erations applicable to gas analyzers, wheelservice equipment, brake lathes and othercomputerized equipment in your shop.

GA S ANALYZERSMost of today’s computerized emissions an-alyzers use infrared technology to evaluatetailpipe emissions. The internal componentthat actually measures the content of theexhaust gas, the “gas bench,” must be cali-brated at regular intervals to ensure accu-rate and consistent test results. The calibra-tion process establishes standard points ofreference, including a zero point (indicat-ing no pollutants) and high point (indicat-ing an unacceptable level of pollutants).Since performance and pollution tests de-tect and evaluate several gases in tailpipeexhaust, these zero and high points mustbe established for each gas measured.

During the calibration process, theemissions analyzer’s sampling systemdraws a special gas mixture (“calibrationgas”) through the gas bench. The frequen-cy of calibration may be determined bythe analyzer’s manufacturer or, if applica-ble, state-regulated inspection and main-tenance requirements.

WHEEL SERVICE EQUIPMENTOlder wheel service equipment (alignment systems andwheel balancers) required frequent mechanical adjust-ments to ensure consistent, accurate results. Thanks tocomputers, the calibration process for this type of equip-ment is much easier (but nevertheless necessary). Today’s

computer-assisted wheel service systemsusually incorporate calibration routines in-to the main system software.

Wheel service systems not equippedwith an automated calibration check fea-ture should be manually calibrated at leastonce a month. Refer to the system’s docu-mentation for the proper procedure.

BRAKELATHESServicing your brake lathe is essential tokeeping it in good working condition. Met-al shavings and other foreign particles can,over time, damage the lathe and cause in-accurate cuts. According to Hennessy In-dustries, brake lathes should be maintainedaccording to a schedule that requires week-ly, monthly and semiannual tasks (see“Brake Lathe Maintenance” on page 55).

ELECTRICAL PO W E RCONSIDERATIONS FORCOMPUTERIZEDEQUIPMENTMost people have no idea that the electricalpower supplied from the wall outlet may beunsuitable for computerized equipmentsuch as an engine analyzer, emissions ana-lyzer or back office shop management sys-tem. The local utility company will nevertell you this, but recent studies show thatpower line disturbances, which are strongenough to disrupt computer operation, oc-

MAINTAINING YOUR SHOP EQUIPMENTMAINTAINING YOUR SHOP EQUIPMENT

Now that you’ve spent big bucks upgrading your shopequipment, here’s how to ensure that it lives to a ripe old age.

BY TIM COOPER

Scott SpecialtyGases, a leadingprovider of cali-bration gasesfor automotiveemissions ana-lyzers, offers acomplete line ofcalibration gas-es, including thepopular ScottyIII. All calibra-tion standardsare available inthe Scotty IIIcylinder size.Scott also offersa wide selectionof regulator as-semblies for allof its gas bottleproducts.

Scott SpecialtyGases, a leadingprovider of cali-bration gasesfor automotiveemissions ana-lyzers, offers acomplete line ofcalibration gas-es, including thepopular ScottyIII. All calibra-tion standardsare available inthe Scotty IIIcylinder size.Scott also offersa wide selectionof regulator as-semblies for allof its gas bottleproducts.

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cur at least twice a week at most com-mercial sites. In rare cases, electrical dis-turbances can damage internal comput-er components. More commonly, how-ever, they cause erratic system operation(keyboard lockups and unexpected sys-tem resets), resulting in damaged or lostdata. Sometimes, the data can be harderto replace than the computer hardwareitself.

But is electrical power a problem inthe real world? Just ask SPX Corp., inKalamazoo, Michigan. The SPX Ser-vice Dept. encountered so many pow-er-related issues with customers that itpublished a six-page Site PreparationGuide for Computerized Equipment.According to Hal Phillips, TechnicalPublications Manager at SPX, theguide has been extremely successful ineducating customers and reducing un-necessary service calls. The SPX Site Preparation Guiderecommends that shops meet three basic requirements tominimize computer power problems—provide clean pow-

er, install the equipment in a favorableoperating environment and properlyroute cables. Let’s examine these re-quirements more closely.

Provide “clean power” to com-puterized equipment. Computersoperate at very low voltages, and eventhe slightest variation in the electricalsupply signal can have a dramatic effecton computer operation. Computers,therefore, require “clean power”—anelectrical signal that is of the correctvoltage and frequency, free of electricaldisturbances and sufficiently grounded.Consider the following factors whenevaluating your shop’s electrical system:

•Power supply and distribution in-tegrity. Most computerized equipmentdesigned to operate in the U.S. re-quires a 115-volt alternating current(VAC), single-phase signal. For best re-

sults, each computerized system should be plugged into adedicated circuit—one not shared by other electrical de-vices. Always use NEMA-certified, isolated ground recep-tacles. Isolated ground means that the receptacle’s groundwire is protected from contact with other grounded sur-faces, such as the receptacle casing, metal faceplate andbuilding conduit.

•Electrical interference. Unfortunately, there’s plenty ofequipment in a shop that can cause electrical disturbances.Electrically “noisy” equipment includes, but is not limited to,air compressors, brake lathes and exhaust fans. Never plugcomputerized systems into a circuit shared by this type ofequipment.

•Power protection. You may think the $15 surge suppres-sor you purchased at the local hardware store already pro-tects your system. Most PCs have more built-in protectionthan these low-end surge suppressors can provide. Surgesuppressors protect connected equipment against voltagespikes only. However, according to Bell Laboratories, over90% of power problems result from voltage sags and inter-ruptions, not from spikes. So even if you own an expensivesurge suppressor, your computer is still vulnerable.

If you use computerized equipment to track and storeimportant business information (financial data, emissionstest records, customer information, etc.), your systemshould be plugged into a line-conditioning device such asan uninterruptible power supply (UPS). A UPS installsbetween the power outlet and your computer. In additionto providing surge protection against spikes, a UPS pro-tects your computer from voltage sags (“brownouts”) andvoltage interruption (“blackouts”).

A UPS continuously monitors the incoming voltage sig-nal, filters out high and low fluctuations and passes a“clean” signal to the computer’s power supply. In theevent of a blackout, the UPS instantly switches to battery-backed power without interrupting computer operation.This normally gives you enough time (usually 10 to 15

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Hunter Engineering’s GSP 9700 VibrationControl System incorporates a conve-nient “Quick Cal” mode. Prior to usingthe equipment to balance a wheel, thetechnician can use this function to quicklydetermine if the system is within propercalibration. If the system is out of limits,the technician is prompted to perform afull calibration—a five- to ten-minutecomputer-assisted procedure.

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minutes) to save your data and shut down the system. It’simportant to make sure the UPS you buy is rated to han-dle the power load consumed by your computerized sys-tem. Consult the equipment manufacturer or local com-

puter dealer for assistance in choosing the right UPS.•Use heavy-duty, grounded power cords. Computerized

products normally include a heavy-duty, three-prong powercord. Never use a two-wire cord or plug the original cord in-

55November 1998

Brake Lathe MaintenanceThe following schedule should be used only as a guideline. Con-sult the equipment manual or manufacturer’s service departmentfor specific procedures and recommended schedules.

WEEKLY MAINTENANCE•Clean surfaces. Use a soft-bristle brush to remove metal chipsfrom all lathe surfaces, including rubber boots and the bench top.Do not substitute compressed air for the brush—the compressed aircan force the metal fragments into undesirable places, resulting inbinding, stiff cross-feed movement and, ultimately, premature wear.•Check/replenish oil level. If necessary, top off the oil supplywith 80W/90 gear oil.•Check/tighten belt tension. Do this while you’re checking theoil. There should be 1⁄8 to 1⁄2 inch of slack with the motor weight onthe belt. Tighten the belt, if necessary.•Inspect/rotate/replace cutting bits. Bits can make the differ-ence between a good machining job and a bad one. A large whitedot, deformed edge or poor microfinish all indicate excessivewear. Some lathes use negative-rake bits on the twin cutter thatcan be rotated, inverted and rotated or switched to the oppositeside for a total of 12 cutting edges per bit. Other bits are simplyreplaced when they wear out. For replaceable and rotatable bits,

it’s usually a good idea to clean the bit holder with a soft-bristlebrush to remove metal chips. A bed of metal in the holder canchange the bit’s cutting angle, resulting in irregular cuts.•Inspect/clean adapters. Use penetrating oil to clean the brakelathe adapters. Reinstall all adapters on their proper mountingpegs on the lathe backboard.

MONTHLY MAINTENANCE•Remove/inspect/clean twin cutter or boring-bar clamp. Usea soft-bristle brush to clean all cross-feed mounting surfaces. In-spect all adapter mounting cups for metal particles embedded inthe back and opposite-side contact points. If necessary, use emerycloth or fine-grade sandpaper to sand the back surface. Whenperforming this task, make sure to sand on a smooth surface.•Lubricate the cross-feed housing. Use a grease gun to applychassis lube to the cross-feed housing. Apply grease until it oozesout of the grease fitting vent. (On older models not equippedwith a grease vent, pull back the cross-feed boot and watch forgrease to ooze out of the cross slide.)

SEMIANNUAL MAINTENANCE•Change the gearbox oil. Remove the cover from the lowerside of the lathe and drain the gearbox oil. Reinstall the cap andfill the case with 80W/90 gear oil to the proper level.

to a light-duty, two-wire extension cord. Also, never attemptto adapt the three-prong plug into a two-prong outlet.

Install computerized equipment in a favorableoperating environment. Proper environmental condi-tions means proper location as well as a temperate operat-ing climate. Consider these factors:

•Location. Install your equipment on a clean, level sur-face. If possible, avoid installing it in a high-traffic areawhere it can be accidentally bumped or jarred.

•RFI interference. Make sure the equipment is posi-tioned at least three to five feet away from telephones orintercoms, and 12 to 15 feet away from powered ma-chines, motors and radio transmitters.

•Ventilation. Allow at least 16 inches of air space on allsides of your equipment. Ventilation air should be free ofsolvent fumes, steam, dust, metal particles and smoke.

•Ambient (room) temperature and humidity. Analyzersand other types of test equipment should not be run be-low 40°F or above 100°F. Never operate desktop comput-ers outside the 50° to 90°F range. Acceptable humidityfor computerized equipment is between 20% and 80%.Always try to minimize static electricity whenever possi-ble; cement floors or static-free mats can be effective inreducing static charge.

Route data cables properly. Cables connect printers,remote terminals, pointing devices and other peripherals tocomputer equipment. When routing such cables, be carefulnot to crimp or nick them. To avoid interference, never runcommunication cables parallel to electrical wiring, and nev-er fasten them to, or locate them near, fluorescent lighting.Finally, avoid routing cables close to electrical equipment,and always try to keep cable runs as short as possible.

ONE MORERULEThere’s one more rule we should mention, and that is toback up your data regularly and store the archive off-site!This is the best protection against data corruption causedby electrical problems, viruses or disgruntled employees.

Calibrating your equipment and practicing a preventivemaintenance program is the best way to ensure its opti-mum performance and trouble-free use. But you alreadyknow this—you tell your customers the same thing everyday. For more detailed information about equipment

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