TM 9-1596 ( Ordnance Maintenance Compass M2 ).pdf

8/12/2019 TM 9-1596 ( Ordnance Maintenance Compass M2 ).pdf

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TM 9 --15SS

W R DEP RTMENT

TECHNICAL M N O L

O RD N N CE M IN TEN N C E

COMP SS MS egust 1 4 1 9 42


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TM 9-15961-3TECHNICAL MANUAL WAR DEPARTMENT,

No. 9--1596 WASHINGTON, August 14, 1942.ORDN NCE MAINTENANCE

COMPASS M

ParagraphScope_________________________________________________ 1Characteristics._ ..___.._.._______________. ______.________ 2Description______________. ..______ .. _____________ 3Carrying case MIft__________________.._______________ 4Care and preservation______________________ _____ __________ 5Inspection_________________ ._______ _. ._ ___...________ 6Maintenance and repair._. .__.___ _____ _____ __ ________ 7Disassembly and assembly_.___.. ._________________________ 8Painting______._____________ ______________ 9PatreAppendix. List of references_________________________ _ 27

1. Scope.a. This manual is published for the information andguidance of ordnancemaintenance personnel. It contains detailedinstructions for inspection, disassembly, assembly, maintenance andrepair of the compass M2, supplementary to those in Fieldand Tech-nical Manuals prepared for the using arm. Additional descriptivematter and illustrations are included to aidin providing a completeworking knowledge of the materiel.Information on the packing, storage, and equipment of thecompass M 2 is not available at this time but willbe m cluded in a revisionof this manual.2. Characteristics.The compass M2 isa multiple-purpose instrument used for obtaining clinometer, angle-of-site, and azimuthreadings. It is used as a reconnaissance instrument for the Field Artil-lery. The compass M 2 is the standard compass of the Field Artillery.The prismatic compassM1918is thelimitedstandard i tem used for thesame purpose.3. Description.The compass M 2 (figs. to, 8, incl.) measuresoverall about 2 by 1 inches when closed and weighs about 8ounces. This instrument is made ofnonmagnetic materials except themagnetic needleand the needlepivot. Principally; this compass consists of the followingmajor units: A b ody and related parts, an angle-of-site mechanism and related parts, a magnetic needle wi th liftingmechanism, an azimuth scale andadjuster, and front and realsights.(1) T he body is provided with a circular gla sswindow held in place by a split retaining ring. This windowkeeps dust wind, and moisture from the interior of the instru-

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ment and protects the internal parts from possible damage and unintentional adjustment. 2) The cover is attached to the body by means of a hinge assembly.The cover contains the mirror, held in position by a split retainingring. A hole in the cover coincides with the small oval window in theA black center line is engraved across the face of the mirror.irror.

FiGDitB The hinge assembly contains an escutcheon pin which serves to parallel the cover with the body when the instrument is fully opened.

1) The angle-of-site index is attached to the lever assembly by means of a screwpassing through the bottom piece of the compass. The arc-shapedslot in the index provides clearance for the adapter upon whichthe compass needle is mounted. The center of the circular partof the index is bent slightly upward, which causes the index to pressagainst the bottom piece, creating friction between these parts.This friction prevents the angle-of-site mechanism from moving


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ORDNANCE MAINTENANCE

unless actuated by its lever. The lever is knurled on one end toprovidea gripforthefingersof theoperator.

2) Thelevel assembly consists ofa tubularlevelvialandacircularlevel vial inclosed in housings which are sweated onto a bracket.Thisbracketis fastened totheleverassemblybymeansofa screw.The circularlevel is used forlevelingtheinstrumentina horizontalplane and the tubular level is used for leveling the angle-of-sitemechanismina verticalplane.

3) The angle-of-site scale and the four points of the compassrepresentedby three letters and a star areengraved on thebottompiece. The and lettersare reversedinorder that courses may

F IG URE 3. Sitesideview .be read directly from the face of the compass. The angle-of-sitescale contains 12 equally spaced graduations, each representing 20mils. The 100-mil graduations are longer than the 20-mil graduations. The 200-mil graduationsarelonger than the 100-mil graduations andarenumberedfrom0 to 1200 in bothdirectionsin 200-milsteps.

1) The magneticneedle assembly consists of a magnetized needle, pointed on bothends, and a jewelhousing in the middle. Apieceofagatewith acone-shapeddepressionin its center is mountedinthejewel housingandpivots on theneedle of the adapterassembly. Thisprovides abearingwithaminimumoffriction. Thenorth-seekingendofthe


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C O M P A S S M2 3-4needle is white; the rest of it is black except for the jewel housing.A thin piece of copper wire is wrapped around the needle to balanceit (compensate for the dip).

(2) The adapterassembly consists of a needle pivot pressed into anadapter which screws into the center of the bottom piece of the compass.(3 ) A lifting pin islocated near the upper left-hand corner of theinstrument. The lower end of the pin engages the needle liftinglever and the upper end projects slightly above the body of thecompass. The arrangement is such that when the cover is closedthe magnetic needle is automatically lifted from its pivot and heldfirmly against the glass window of the compass .(1) The azimuth scale is held inthe compass body by means of a split retaining ring. Teeth are cuton the under side of the scale to engage with the pin teeth of theadjuster. By means of this arrangement the azimuth scale may berotated approximately 1,800 m ils. The top surface of the scale,painted white, is divided into 320 equally spaced graduatioTis, eachrepresenting 20 mils. The graduations, filled in with white, arenumbered from 0 to 6,200 mils in 200-mil steps.(2 )The azimuth scale adjuster (fig. 4 ) is slotted on one end topermit rotation by means of a screw driver. The other end is constructedas a pin gear to engage with theteeth cut on the under sideof the azimuth scale.(3) The azimuth index is driven into the body through a holecovered by therear sight hinge. The point protrudes into the interiorof the compass and provides the means for orienting the azimuthscale to the local magnetic declination.

(1) The front sight assembly is fastenedto the body by two screws. When not in use the front sight isfolded against the topsurface of the cover.(2) The rear sight assembly fastened to the body by two screws,consists of a rear sight holder and a bracket. The rear sight ishinged to theholder, whichin turn is hingedto the bracket. Provision is made for folding the rear sight against the window insidethe cover and the cover is closed over it when the instrument is notbeing used.

4. Carrying The carrying case M 19 (figs. 5 and 6) isa velveteen-lined leather case constructed to fit the general contourof the compass M2. The cover of the case is kept closed by meansof a snap fastener attached to the cover. A leather loop, attached


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TM 9-15964-5 ORDNANCE MAINTENANCEon the back of the case permits suspension of the case from the beltof the user5. Care and preservation. 1) The followingcleaning materialsare to be usedwith this materiel:Alcohol, ethyl (forcleaning the glass parts .

Solvent, dry-cleaning (for cleaning metal parts .Paper, lens tissue.Brush, camel s-hair.

ZIMUTH SC LE

SC LE DJUSTER

DJUSTER RET ININGSCREWRA PD 1711

FIGURE 4.Azimuth scale adjustment mechanism. 2) Care should be exercised when cleaning the mirror that noethyl alcohol overruns onto the edges of the mirror. The mirror is

set in putty and the alcohol might loosen this putty setting. 3) Metal components should be cleaned by means of a clean cloth

moistened with dry-cleaning solvent Glass parts of the compassshould be cleaned with ethyl alcohol and clean lens tissue paper. 4) Wipe all dust, oil or other foreign substances off the carryingcase using a damp (not wet) sponge. Allow the leather to becomepartially dry, thenrub it vigorously with a soft, dry cloth.

Z > This instrumentshould be handled carefully to avoid unnecessary shocks. Keep the


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COMPASS M 5compass in the carryingcase when it is not being used After usein wet weather wipethe compass dry before placingitin thecarryingcase.

When the instrument is moved fromone positionto anotheroris not in use, the cover should be closed. This lifts the needle offits pivot andprevents injuryto the pivot.

rt) Particular care should be exercised to prevent bending thesights or the cover hinge. Before closing the cover the rear sight

F IQUKE 5.Carrying case M19.shouldbe folded over so thatit lies flat on the compasswindow. fthis precaution is notobserved the window maybe broken.

When the instrumentis stored for any length of time do notplace itin clo se proximity to electric motors generators transformers or electric conductors carrying appreciable amounts ofcurrent. These set up electric fields which in time may weaken themagnetismof themagneticneedle

Moisture due to condensation may collect in the instrumentwhen the temperature of theparts is lower than thatof the sur-


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TM 9-1596COMPASS M2 5 6

rounding air. This moisture, if not excessive, can be removed byplacing the instrument in a warm place./) No lubrication is required for this instrument.

When the cover is open, the direct rays of the sun should notbepermitted to fall on the instrument for any appreciable length oftime. If this precaution is not observed, damage may result to thelevel vials.

(2) Keep the top piece fastened withthe fastener provided at all times except when removing or replacingthe compass. This prevents the entrance of dust and foreign objectsinto the case.

At certain intervals, apply a small amount of oil, neat s-foot,to the leather. Climatic and service conditions are factors whichdetermine the frequency of oiling. Experience has shown that during the first few months of use new equipment requires at leasttwo applications of neat s-foot o l per month. Thereafter it isentirely a matter of judgment, as indicated by the appearance andpliability of the leather. Frequent light applications of oil are muckmore beneficial than infrequent heavy applications.

If the leather has become wet from whatever cause, dry it inthe shade. Never dry leather in the sun or close to a steam radiator,furnace, or boiler.

6. Inspection. (1) Inspection is for the purpose ofdetermining the condition of the compass M2, whether repairs oradjustments are required, and the remedies necessary to insure serviceability and proper functioning.

(2) The purpose of the basic inspection is to determinethe conditionof the compassand locate basic faults. As a result, proper dispositionof the instrument can be made and the necessary action taken or reommended. Inspection forms (OO Form 7228 or OO Form 7229,fig. 7) are provided for recording the results of the inspection. Instructions concerning the entries to be made are printed on the backof the form.

(3) The detailed inspection is performed by the instrument repairman. The purpose of this inspection is to determine the specificrepairs required to place the instrument in a serviceable condition.The inspection procedure may vary with each instrument, dependingon the faults indicated by the preliminary inspection. Inspectionforms and methods used in connection with the detailed inspectionare described in TM 9-2602.

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F I G U R E 7.Inspection report form.

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TM 9-1596COMPASS M2 6Z > The following inspections are

to be made:1) Strength of magnetic needle.2) Magnetic needle lifting mechanism.(3) Magnetic needle dip. 4) Alinement of mirror and rear sight.5) Circular level vial adjustment.6) Tubular level vial adjustment.7) Alinement offront and rear sights.(1 ) An instrument repair kit containingcommon tools and supplies for instrument inspection and repair is

furnished to ordnancemaintenancecompanies. This kit, instrumentrepair, replaces kits previously issued as kit, optical repair,for FieldArtillery,and kit, optical repair, forharbor defense.) Most of theitems inthe kit, sut h as screw drivers, etc., requirenodescription astheir uses are self-explanatory.

2) n addition to the above-mentionedtools, the following will benecessary to carry out the inspection:

Sensitive spirit level.6) Common hand tools screw drivers, wrenches, etc.). < ? ) Brass or other nonmagneticmaterial) surface plate.Sturdywork bench affording clear visionto the front.

Tolerances, orallowable errors, are specified wherever necessary toindicate the accuracy ofperformance of the instrument. n general, an instrument is considered unserviceable if theerror inany part exceeds the specified tolerance. However, it mustbe realized thatthe specified tolerance is intended to serve mainlyas a guidefor the inspector, and must be supplemented by good judgment on thepart of theinspector. These tolerances donot necessarilyinferthat the instrument repairmanshould not attempt to reduce theerrors to lower limits if time and conditions permit.

1) Record the serial number ofthe instrument. Examine the compass M 2 for completeness, generalappearance, legibility of scales, condition of paint, and for loose,broken, orbent parts.(2) Observe whether or not the level vials are broken.Remove the window retaining ring and window (figs. and 9).Press down lightly on the tubular and circular level vials. Notewhether the vials are firmly set in theirhousings. Replace windowand window retainingring.


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TM 9-15966 M INTEN NCE

3) Uncover the com pass and m ove the rearand frontsightsabout their hinges. Note whether theseparts m oveproperly about their hinges without un ue looseness or binding. 4) Loosen the adjuster retainingscrew.Rotate the azimuth scale adjusterby means of a screw driver, alternately in one direction and th en in another until the stops arereached. Note whether thismotion is smooth, without binding or

7FIGUKB 8.Method of removing window retaining ring.

excessive looseness. After checking, tighten the adjuster retainingscrew.5) Uncover the compass and

place it on a leveled surface away from steel or iron objects. Thewhiteneedle end should point toward the north. f this end pointstoward thesouth, thepolarity of the needle has been reversed.5) Close the cover of the compassand shake it gently. Note whether any looseness of the magneticneedlecan be perceived.

Open the coverand placethe compass on a leveled surface plate. Displace the mag-

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COMPASS M

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netic needle by bringing an iron or steel object close to it. Withdraw the object. Note whether the needle swings freely about itspivot and assumes the equilibrium position in a relatively short time.

Open the cover and place the compass on a leveled surface away from steel or iron objects. Note whether the ends ofthe magnetic needle are approximately level with the azimuth scale. 6) Move the lever assembly to thelimit of its movement in each direction. This motion should besmooth, without excessive friction or looseness./. 1) Instruments found defective must berepaired or adjusted to render them serviceable. Defects noted andaction to be taken must be entered on the inspection form for eachinstrument. The action to be taken will be governed by the facilitiesavailable. If the facilities of the section do not permit satisfactoryrepair or adjustment, the unserviceable instruments will be passedon to a higher maintenance echelon; replacement items should thenbe issued to the using arm.

2) f no faults are found in the basic inspection, the instrumentis determined to be in a serviceable condition. f minor faults whichcan be readily corrected are found, the necessary repairs should bemade and the instrument thereby placed in a serviceable condition.Certain basic faults do not lend themselves to simple repair or adjustment, as they must be further localized before the necessaryrepair can be accomplished. f such faults are found, further inspection will be necessary to complete the inspection procedure in detail,and tp determine the specific correction necessary to make the instrument serviceable. Procedure for detailed inspection and correctionis given in paragraph 7.7. Maintenance and repair. 1 ) Place the compass with its cover open on a level surface. No magnetic materials should be placed in close proximity tothe compass during the procedure.2) B y means of an iron object such as a screw driver displace themagnetic needle about 30 from the equilibrium position. Removethe screw driver, allowing the needle to swing to the right and leftof its equilibrium position. B y means of a time-interval recorder,measure the time required for the needle to complete five periods. Aperiod of the needle may be defined as the time required for thenorth-seeking end of the needle to move from its maximum displacedposition right of the point of equilibrium, then to the extreme left,and back to the initial position. If the time recorded by the time-interval recorder is more than 20 seconds or more than 4 seconds per

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COMPASS M2 7period, the magnetism in the needle is weak. If this is the case,replacement of themagnetic needle is necessary.

(1) Open the cover of the compassuntil the cover is parallel with the face of the compass. By meansof a sharp tool pry the retaining ring out as shown in figure 8.Care should be exercised that the glass is not broken when the toolis pushed underneath the ring.

(2) Lift out the compass window and the magnetic needle assembly.Place a serviceable magnetic needle assembly in position, and replacethe other parts in reverse order of the disassembly.

Open the coverof the compass. Press the needle lifting pin down so that its endis flush with the compass body. Note the position of the magneticneedle with respect to the azimuth scale Gently shake the compasswhile holding the needle liftingpin in the position mentioned above.Again note the position of the magnetic needle with respect to theazimuth scale. If there has been any noticeable movement of theneedle, an adjustment of the magnetic needle lifting mechanism isnecessary.

(1) Remove themagnetic needle as explained in above. Remove the needle sleeve(2) Remove the lifting lever from the compass. Bend theleverslightly and replace in the compass. Exercise care to see that theend of the lifting lever is placed underneath the lifting pin uponreassembly. Check the operation of the lifting pin and magneticneedle. Bend the lever slightly more, if necessary. Replace all removed parts in the reverse order of disassembly.

(1) Place the compass on anaccurately leveledbrass plateor other nonmagnetic surface. See thatno magnetic substances are in close proximity to the compass. Remove the window retaining ring and window.

(2) Note whether the magnetic needle is level with the azimuthscale within plus or minus 0.031 inch. If the deviation is more thanthis, the sliding weight on the needle will have to be moved. Theneedle is balanced for the locality of manufacture. If the compassis moved to another locality closer or farther away from the NorthPole than the manufacturing locality, an adjustment of the slidingweight will usually be necessary.

/. (1) Lift the magnetic needle fromits pivot. Slide the weight, consisting of several turns of copperwire, in accordance with the condition of unbalance (fig. 10). Ifthe weighted end of the needle is above the azimuth scale, slide the

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MAINTENANCEweight a short distance outward and if the weighted end of the needleis below the scale, slide the weight inward toward the pivot).

2) Place the needle on its pivot and check the adjustment. Eepeatthe adjustment if necessary. Eeplace all removed parts. 1 ) Place thecompass on a level surface plate. Lift up the cover so that it makesan angle of approximately 90 with the face of the compass.

2) Lift up slightly on the rear sight and note whether the tip isin alinement with the lower part of the etched line on the mirror.3) Lift up further on the reai- sight and move the cover towardthe sight until tip of the sight, is adjacent to the upper part of themirror. Note whether the tip of the sight lines up with the upperpart of the etched line on the compass mirror. f not, an adjustmentof the compass mirror or replacement of the rear sight assembly isnecessary.

F I G U R E 10.Magnetic needle, assembly.1) Hold the compass cover

with the left hand, the cover first being opened to lie flat. With asharp tool in the other hand, pry out the retaining ring fig. 11).Shift the mirror until the etched line is in correct alinement with thesight tip. Eeplace the retaining ring by first placing the ends of thering adjacent to the stop pins and then pressing the ring into itsgroove. 2) Check the alinement as explained in above. Repeat the adjustment if necessary. If alinement cannot be secured in this way,either the rear sight or the cover hinge is unserviceable and replacement of those parts is necessary.

Place the compass ona level surface plate. Note the position of the bubble. If the bubbleis not in the central position, adjust the circular level vial.1) Eemove the compass windowby first removing the retaining ring figs. and 9). Carefully lift-out the magnetic needle.

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COMPASS M2TM9-1596

(2) Removethelevel assembly by first removingthefillister headscrew. Bend the bracket slightly. Keplace the level assembly inthecompass. With the compass on a level surface, check the positionof thebubble. Kepeat the adjustment ifnecessary. 3) Place the edge ofthe compass on a leveled surface and adjustthe angle-of-site indexin themanner explainedin Z2) below. Reassemble theremovedparts in thereverse order of disassembly .(1) Openthe coverparallelwith the face of the compass. Place theedgeof thecompass

F IG U RE 11 . Method of removin g mirror retainingringon a flat,horizontal referencesurface so thatthe angle-of-siteindexpoints toward thisreference surface.

2) By means of the angle-of-sitelever,center thebubble in thetubularlevel vial. Notethe indication ofthe angle-of-siteindexonthe associatedscale. f this indicationismorethan10mils, an adjustment isnecessary.

( ) Remove thewindowretainingring, window, andmagneticneedleasexplainedin5(1) and(2)above.Placetheedge ofthecompasson a flat,horizontal surfaceso thattheangle-of-site indexpoints towardthisreference surface.

2) Set the angle-of-siteindex to indicate zero on theangle-of-sitesca le. Loosen theindexscrew and shift the level assembly untilthe17


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TM 9-1596MAINTENANCE

bubble is centered. Tighten the index screw so that the angle-of-siteindex levermay be moved without excessive friction or undue looseness.Eeplace all removed parts.

T O O pen thecompass so that the cover is parallel with the face of the compass.Place the edge of the compass on a flat, horizontal reference surfaceso that the angle-of-site index points toward this reference surface.Fold the rear sight holder out parallel with the fa ce of the compassand the rear sight perpendicular with its holder. Fold out the frontsight so that it is approximately perpendicular to the plane of themirror.(2) Place the edge of a piece of cardboardon this leveled surfacenext to the sighttips. ccurately drawa horizontal line on the cardboard, passing through the point touched by the tip of the rear sight.The tip ofthe frontsight should also pass through this horizontal linewithin plus or minus 0.020 inch. Move the rear sight holder outapproximately 30. Again note whether the horizontal line passesthrough the tips of both sights within 0.020 inch. If the deviationfrom the horizontal is more than this, an adjustment is usually indicated.

Loosen thescrews by which thefront sight is attached to the compass cover. M ove the sight in direction of correct alinement and tighten the screws. If the alinementcannot be secured in this way and if the mirror and rear sight areproperly alined replace the front sight. For disassembly and reassembly procedure of the front sight refer to paragraph and8. Disassembly and assembly.To preserve the parts of the instrument, it is necessary to exercise care and close attention duringdisassembly, cleaning, and adjustment. To avoid injury to the instrument the proper tools should be usedfor each disassembly andreassembly jo b. The extent of disassemblyfor any certain repairjob is determined by the repairman when he makes his detailedinspection. (1)Hold the cover firmlyin one hand. Insert the blade of a sharp tool or penknife betweensplit retaining ring and mirror near the end of the ring and twistthe blade slightly, thus removing the ring (fig. 11).(2) Extend one fingeror a small blunt object through the windowopening in the cover and push the mirror upward (fig. 12). Carefully slide the mirror out. Exercise care to avoid losing the shimsunderneath the mirror.

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FGUR1smyomo

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MAINTENANCE1) Remove all old putty from

the compass cover. Place a little putty on the upper edge of thecover. Follow thesame procedure as for disassembly except in thereverse order.2) Aline the etched line of the mirror with the rear sight inaccordance with instructions given in paragraph

1) Removethe split retaining ring by inserting a screw driver blade betweenthe ring and the window fig. 13). Care should be exercised thatthe screw driver blade does not slip away from its proper positionduring this procedureand do injury to the instrument or to the handsof the instrument repairman. Carefully lift out the window.2) Lift out the magnetic needle assembly and sleeve. Carefullylift up on the needle lifting lever and remove from the compass.Remove theneedle pivot fromthe compass byunscrewingtheadapterassembly from the bottom piece. Unscrew the lifting pin bushing.Extract the lifting pinfrom the compass body.

1) Replacetheneedle lifting pin with bushingin the reverse order of disassembly.When replacing the needle lifting lever, make sure that theend ofthelever is underneaththe lifting pin. To facilitate this procedure,temporarilyturn the compass upside downwhen replacingthe liftinglever. 2) Replace the remaining parts inthe reverse order of disassembly.When replacing the split retainingring, put the ends of the ring inthe groove first beforepressing the ringinto position. 1) Remove the window as explained in c l) above. Lift off the magnetic needle assembly fromits pivot. Remove the needle lifting lever.

2) Unscrew the fillister head lever screw and remove the levelassembly from the compass figs. 14and 15). lean out all brokenparts andthe old plasterof paris setting./. 1) Replace the tubular or circular level vial whichever may be the case) and center it in thehousing opening. Pack it with gypsum, calcined plaster of paris)

SNL K-2) that has been mixed to medium consistency. After theplaster of paris has set, paint the exposed surface of the plaster ofparis on the bottom side of the circular level vial and on the ends ofthe tubular level vial with black paint.

Replacethe level assembly in the compass and adjust the levelsby following the procedure given in paragraph 7j 2) and Replaceall removed parts in the reverseorder of disassembly.

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COMPASS M2

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COM PASS M2 8-91)Remove the

compasswindowby followingthe proceduregiven in cl)above.2) Removetheazimuth scale splitringbymeansofa screwdriver.Lift outthe azimuth scale. Removethedogpoint srewandextracttheazimuth scale adjuster fromthe compassbody. Followthesameprocedure for reassembling as fordisassembling, butin the reverseorder. Care should be exercised thatthe teethon theazimuth scaleareproperlymeshedwiththe pinteethontheadjusterbefore replacingthe otherparts.

F IG U R 15. Disassembly of level via ls.Refer tofigures 14 and 16. Remove the

frontorrearsight byfirstremovingthetwocountersunk head screwsfromthe compass body. Access can now be hadfor drivingoutthetaperedpinsin thesightsifnecessary .

Follow the same procedurefor reassemblingasfor disassembling, butinthereverseorder. Toavoid injuringthepartsinvolved, care shouldbe exerc ised thatthetapered holes inthesights andholdersareproperlymatchedbefore thepins aredrivenintoplace. The front andrearsightsshould be assembledsothat thecountersunk surfaces on the sights face each other when the sightsareinposition, as shown in figure17. Foradjustment,refer to paragraphs and

NOTE. After assembly has been comple ted the instrument should again bechecked to see that it conforms to the inspection requirements listed in paragraph 56.9 Painting. Thepaintingofinstruments mustbe

supervisedby someone familiarwith the functioning of theinstruments. Care shouldbeexercised thatnopaint comes in contact with

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COMPASS M2scales, gear teeth, and bearingsurfaces. Ordnance materiel is paintedbefore issue and from time totime afterwarddepending upon serviceconditions andclimatic conditionstowhich the materiel is subjected.

COUNTERSUNK SURF E

FRONT SIGHT

COUNTERSUNK SURFACE

REAR SIGHT'

COVER

_80DY

RA PD 7F IGURE 17.Location of countersunk surfaces offront andrear sights.

1) All surfaces to bepainted mustbe dry and freeof dirt, oil, grease, and rust. Forcleaning, use dry-cleaning solvent and rinse with hot water. Dry in anair stream. t must be remembered that frequent washing of metal

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TM9 ORDNANCE MAINTENANCE

components in the same batch of solvent will soon render it unfit forfurther use, since it easily becomes saturated with grease, oil, and dirt.The solvent must be changed frequently.

2) Remove loose paint around marred partsby rubbing those parts with paper, flint, No. 1. Dust off all loosesand and paint flakes.

Apply the paint with a brush or with a spray gun.Exercise care to avoid splashing or spraying paint on parts which arenot to be painted. Finished colors must match authorized or prescribed hues. Minor deviations of pigment proportions are permissible, if necessary to match colors.2) Use white scale filler for painting graduations. Clean thegraduation marks and apply a thin coat of white filler. Wash offsurplus filler with soap, castile, and water; rinse in clean water anddry.

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COMPASS M2A P P E N D I X

LIST OF REFERENCES1 . Standard Nomenclature Lists.Cleaning, preserving, and lubricating materials.- NLK-1

Fire-control materiel:Compass M2_______________________ SNL F-219Kit, instrument repair__________.______ SNLF-206Truck, instrument repair, Ml____________ SNLG-92Current StandardN om enclature Lists are as tabu

lated here.An up-to-date list of SNL's is maintained asthe "Ordnance Publication for Supply Index ___________________.________ OPSI

Cleaning, preserving, lubricating, and welding materials, and similar i tems issued by the Ordnance Department________________________________TM 9-850

Fire-control materiel:Field artillery fire-control instruments- _______ T M 6-220Instruction Guide , the instrument repairman__ __ TM 9-2602Compass M2_______________________ TC22Miscellaneous:7 5-mm gun materiel M 1897 and modifications___ TM 9-30575-mm gun and carriage M1917 and mo difications-. T M 9-31575-mm howitzer materiel________________ T M 9-320105-mm howitzer materiel M 1 A 1 and M2______ T M 9-325155-mm howitzer materiel M 1917, M1918 and modifications__________________.______T M 9-330

Maintenance: aintenance of materiel in hands of troops.___ OFSB 4 Specia l Instructions, Group F____________ OFSB 4-8Storage andissue____________________ T M 10-250

[A. G . 062.11 (6-18-42).]

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ORDNANCE MAINTENANCEBYORDER OFTHE SKCKETARYOFWAR

G C MARSHALL,OFFICIA L J. A ULIO,

D IS T R IB U T IO NE9 2);IBn 1);1C 3) or 91 mediumandheavy maintenancecompanies).Forexplanationof symbols see 21-6).

Documents

TM 9-1596 ( Ordnance Maintenance Compass M2 ).pdf