compound slide

7/28/2019 Compound Slide

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Compound

D r i l l i n g a n d M i l l i n g T a b l eSpace drilled holes accurately, and do milling,

grinding, and keyway-cutting on your drill

press with this compound table attachment

By WILLIAM H. GRUBB

ITH no power tool except your drillpress, you can make this compoundtable at a cost of less than $15.00, and

with it do the work of compound attachmentscosting much more.

For instance, suppose you want to drill twoholes in a piece of work exactly 2 in. center-

to-center. Secure the compound base plateto the drill press table, clamp the work piecein the vise, and line up and drill the first hole.Then traverse the compound in the properdirection with one of the lead screws (40turns for 2 in.), and drill the second hole. Itwill be 2000 thousandths-of-an-inch from thefirst, if your compound attachment is care-fully made. This is accuracy you can't get byordinary measuring means. You can also dokey-seating, as shown in the photo, and otherlight milling operations in your drill press

with this attachment, providing the run-outof your drill press spindle is not excessive.The design takes advantage of the precisedimensions to which cold rolled steel is man-ufactured, eliminating the need for any ma-chine work other than drilling.

Get the steel parts (see Materials List)

36

w

sawn to correct length,if possible, when youbuy them from yourlocal steel supplyhouse. This will leaveonly hand filing of theends to finish thepieces. Note that onlythe two 3-in. long car-riage plates (Figs. 3and 5) require exact

squareness of the ends,as only the ends ofthese two parts areused as mating sur-faces with other parts.Use a machinist's try-square to check thetrueness of the ends,and take care to getthese pieces exactlythe same length aswell as square.

Squareness andmatching length ismore important thanthat they be exactly3 in. longthey could

be slightly longer or shorter than this withoutharm. Elsewhere in the structure, the endsof the cold rolled parts are in the open andneed to be trued up only to the extent of pro-ducing a neat, workmanlike appearance.(The ends of the ways, although they are ad-

jacent to the end plates, are not attached to

them.)File the ends of all the cold rolled pieces,

then lay out the drilling pattern on two of theend plates (Fig. 3) and mark them for iden-tification. Stack together one of these markedplates with two 4-in. carriage plates and anunmarked end plate, in the same relation toeach other they will bear in the completedstructure (Figs. 4A and 1). Line up theiredges with a try-square, using the 3/8 x -in.gib stock to establish the -in. inset of thecarriage plate edges from the end plate edges

(Fig. 4).Clamp the four pieces solidly together,

then drill the guide rod holes through all fourplates, first with a small drill (about .188 in.),following up with a larger drill and finishingwith the correct size drill. In drilling theseholes, greater accuracy will be had if one of

Cutting a keyway in apiece of cold-rolled shaft-ing is easy with the com-pound table. In this set-up,depth of the cut is con-trolled with the left handlead-screw, while the workis advanced with the right

hand lead-screw.


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the guide rod holes isfinished through allfour plates, and thenplugged with a pieceof the -in. guide rodstock while the nexthole is being drilled.Drill the lead screwhole through threeplates, but only half-

way through thefourth, to -20 tapdrill size (.453 in.).Then unclamp anddrill this hole to in.in the first, second, andfourth plates. Tap the.453-in. hole -20 inthe third plate (thesecond carriage plate),then lay out, drill, andtap the gib screw holes

in the other carriageplate. Stack, clampup, and drill the sec-ond set of end platesand carriage plates inthe same manner asthe first set (Fig. 4B).Next, lay out, drill, andtap the guide rod setscrew holes in the fourend plates (Fig. 3).

Smooth up the edges of the base plate and

clamp one of the ways to it, spacing it fromthe edges according to Fig. 2. Lay out thesix screw holes on the way, and drill throughthe way and base plate to tap drill size (#8).Then remove the way and drill and counter-bore the holes to finished size, to receive the-in. sh (socket head) capscrews. Be sureto recess these screw heads fully into the wayso the carriage plates will not touch themwhen the table is traversed. Tap the screwholes in the base plate, then attach the wayto it with six capscrews.

Make the top plate next (Figs. 2 and 2A),noting the hole layout in its surface whichprovides for the attachment of the fixed andmoveable vise jaws and other work-holdingdevices. Drill and tap these holes first, thenclamp the way to the top plate and drill andtap the six screw holes for the attachingholes, following the same procedure as forthe lower way.

Next, clamp up the four plates comprisingthe carriage, taking care to get the -in. off-

set of the plates exact (Fig. 5) and the platesat 90 to each other. Insert the -in. guiderods to aid in holding opposite plates in line.If you got the ends of the 3-in. carriage platesperfectly square when you filed them, youwill have no trouble with this line-up; if not,it will be necessary now to true them up.Then drill and tap for the eight -20 sh, cap-

MATE RIAL S LISTCOMPOUND TABLE

No .Req. Size and De scr ipti on Use

STEEL

1 x 4 x 12" long CRS (co ld rolled steel) top plate2 x 2 x 11" long CR S wa ys4 x 2 x 4" long CR S end plates2 x 2 x 4" long CR S carriage plates2 x 2 x 3" long CRS ca rria ge plates3 x x 4" long CR S vis e2 3/8 x 14 x 4" long CR S gibs4 " dia. x 12" long CR S guid e rods2 " dia. x 12" long CR S lead scr ews21.937"dia. x 1 long CRS handwheels2 3/8" dia. x 2" long CR S spinn ing hand les2 " dia. x 2" long CR S vis e2 " I.D. x " long col lars lead sc rew s1 x 12 x12" HR S (hot rolle d steel) base plat e

FASTENINGS

23 1/4 - 20 x " sh (soc ket head) capscrew s carriage, ways,vise

12 - 20 x 1" fh (flat head) machine sc rews end plates14 - 20 x " sh sets crew s guide rods, (j ibs,

handles2 6 - 32 x " sh sets crew s spinning handles1 - 20 x 2" sh se tsc rews v i se

HOME-BUILT POWER TOOLS 37

screws, counterboring to recess the screw

heads.Note that the two gibs (Figs. 5A and 1)

offset the carriage with respect to the upperand lower ways. Install the lower gib andset the carriage and one end plate on oneend of the lower way, orienting it properly,then insert the guide rods to hold the partsin alignment and clamp the assembly to-gether. Drill, tap, and countersink the threescrew holes in the underside of the base plate

BASE PLATE

LOWER WAY

SCREW

GIB

NOTE: LEAD SCREWHOLES HALF DEPTHIN THESE TWOEND PLATES.

TOPPLATE

VISE (OPTIONAL) TAPPED HOLES FORHOLD - DOWN DEVIC ES

UPPER WAY

GIB


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NOTE: LOWER WAY SHOWN

IN DOTTED OUTLINE

SOC. HD. CAPSCREWS - 6 HOLES

DRILL & C'BORE FOR

WAY

C.R.S.- 2REQ.

(HOLE PATTERN SAME.

BOTH CORNERS)

DRILL & C'SINK FOR

F.H. SCREWS - 6 HOLE5

BASE PLATE

H.R.S.

DRILL & C'SINK FOR

F.H.SCREWS

6 HOLES

DRILL &TAP

20 HOLES IN 1" SQ.

GRID PATTERN

TOP PLATE

C.R.S.DRILL & TAP

AT ASSEMBLY

3 HOLES

A

UPPER WAY

INSET

VISE END

TOP PLATE, UNDERNEATH VIEW

(NOTE RELATION OF WAY TOVISE END OF TOP PLATE.)

DRILL & TAP

2 HOLES EA. PLATE

DRILL 3HOLES ON

CLAMP-UP (SEE FIG. 4)

END PLATE

C.R.S - 4 REQ.DRILL 3 HOLES ON

CLAMP-UP (SEE FIG. 4)

NOTE: THIS SPACING

IS IMPORTANT, TO AVOID

INTERFERENCE WITH

GUIDE ROD HOLES IN

3" CARRIAGE PLATES.

DRILL DRILL & TAP

DRILL & TAP 20 - 2 HOLES

(ONE PLATE ONLY)4" CARRIAGE PLATE

C.R.S - 2 REQ.

3 HOLES ON

CLAMP-UP

(SEE FIG. 4)

3" CARRIAGE PLATE

C.R.S.- 2 REQ.

2 HOLES (ONE

PLATE ONLY)

DRILL & TAP 2 HOLESEA. END AT ASSEMBLY

and insert the screws. Slide the carriage tothe opposite end of the way and repeat theprocedure to secure the other end plate.

Then install the end plates on the top plate,following this same method. As the ends ofthe ways are not attached to the end plates,

squareness of these ends is not a factor incontrolling the trueness of these assemblies.After all four end plates are installed, slidethe carriage back and forth on the lower way,and slide the top plate back and forth on thecarriage. If there is any binding, correct itby bringing the out-of-square parts into true

with paper or brass shims (Fig. 5), or if thebinding is very slight, by applying fine auto-motive valve-grinding compound to the guiderods and sliding the parts back and forth.

Make the handwheels next (Fig. 6). Turnthese on a lathe if you have one, but if not

you can make them on the drill press if thepieces have been sawn fairly square. Drillthe -in. center hole and the -20 set screwhole in the handwheel blanks first (Fig. 6).Then chuck a piece of -in. cold-rolled rodin the drill press, put a handwheel blank onit, and use a file to form the chamfer and fin-

38


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ish the ends. The spinning handles (Fig. 6)can be machined as shown, or can be leftstraight with the ends filed round in the drillpress. Secure the handles solidly in the hand-wheels with 8-32 set screws (Fig. 6).

To calibrate the handwheels, measure theirexact circumference (this will be 6.087-in. if

the blank is 1.938-in. diameter) w ith a stripof paper and make a drawing with this di-mension divided into fifty equal parts by lay-ing out fifty eighths-of-an-inch (6 in.) be-tween two lines drawn 90 to the handwheelcircumference line (Fig. 8). Transfer the

eighth-inch marks across, then cut a stripout of the layout, and wrap this around thehandwheel, holding it with scotch tape. Witha sharp cold-chisel, cut .125-in. long graduationmarks into the edge of the handw heel. Makeevery 5th and 10th graduation -in. long,and identify every 10th graduation with the

proper number stamp (0, 10, 20, etc.). Eachgraduation will represent l/1000th-in.Complete the assembly of your compound

table by installing the lead screws, with theirhandwheels and retaining collars, and by at-taching the vise parts on the top plate.

38HOME-BUILT POWER TOOLS

MARKEDEND PLATE

GUIDE ROD HOLES,DR ILL THROUGH

ALL 4 PLATES

INSET

UNMARKEDEND PLATE

LEAD SCREW MOLE,DRILL TO TAP DRILL SIZE

THROUGH 3 PLATESTHEN UNCLAMP (SEE TEXT)

4 CARRIAGE

PLATES

CLAMP-UP"A"

OFF5ET

LEAD S CREW HOLE,TAPPED IN THESETWO PLATS ONLY

SHIM, IFNECESSARYTO MAKE TRUE

GIB SCREWHOLES INTHESE TWOPLATES ONLY

20S.H.CAP SCREWS6REQ.

OFFSET

NOTE- OPPOSITE PLATES MUST BE PARALLEL,ADJACENT PLATES 90' TO EACH OTHER.

CARRIAGE ASSEMBLY

TOP PLATE UPPER WAY

SETSCREW

GIB

A

CARRIAGE

NOTE OFFSET OF WAY& CARRIAGE.OFFSET OF LOWER WAY SIMILAR.

SHAPE TO SUIT OR LEAVE STRAIGHTD I A .

DIA.

HANDLE

C.R.S.- 2 REQ.(50 EIGHTHS)

90

TRANSFERMARKS

A( ROSSFIXED JAW

M O V A B L EJAWS

CUT STRIP OUT TOTRANSFER MARKSTO HANDWHEEL

VISE, SUGGESTED DESIGN

DIA. x 2" LG. R ODS

HOLES

DIA.

FIT SETSCREW2 HOLES

DRILL DEEP TO

DIA.

FOLLOW NOTES FORCLA MP- UP "A" & TEXT

IN DRILLINGTHESE HOLES.

END PLATES

3 CARRIAGEPLATES

INSET, 3 SIDES

CLAMP-UP "B"

DRILL & TAP #8-32FOR SETSCREW

PRILLDEEP

DRILL i TAPFORSETSCREW

BOREDEEP

HANDWHEEL

C.R.S. - 2 REQ.

GIB

C.R.S. - 2 REQ.

LEAP SCREW

C.R.S. - 2 REQ.

GUIDE ROD

C.R.S. - 4 REQ.

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