OPERATING INSTRUCTIONS
ATTENTION PLEASE!
ALIGNMENT FIXTURE
aligns drill in chuck both radially and axially with sharpening
EYE SHIELD . Positively at
PRECISION CHUCK . .
Your Darex Drill Sharpener is assembled at the factory such, that it takes only minutes to set up and operate. HOWEVER, since proper procedure is essential for satisfactory results read the operating instructions carefully on a step by step basis prior to starting. Please follow these steps:
- 1. Read and pay close attention to the safety precautions.
- 2. Learn to produce a "standard point" first as shown on page 2.
- Become proficient on sharpening drills of at least 1/4" diameter or larger before attempting smaller drills.
After a little practice, you will be producing accurate points in less than a minute .
Getting to know your Darex Precision Drill Sharpener
The Darex drill sharpener has an unusually broad capacity for handling 1/16 through 1/2-inch, fractional, letter, number, metric, carbon, high-speed, carbide, straight or tapered shank drills. An optional chuck is available to extend the range to 3/4-inch. Clearly marked standard settings quickly produce precision "factory-point" drill geometry. Point angles, relief clearance and chisel point angles can be reset in seconds, without tools, to produce the optimum geometry for soft or hard materials, metals, plastics, wood, etc. Selfcentering, multi-chamfer and other special points can be produced as well.
WHEEL GUARD . more than meets OSHA requirements for strength and permissable opening. Provision for grinding dust exhaust hook-ups also provided.
HEAVY DUTY MOTOR . . industrial rated 1/2 HP, 115 vol
3450 RPM motor, sealed ball bearing construction perma nently lubricated.
POINT ANGLE ADJUST-MENT...finger tip adjustment of point angle from 80° to 190° with common drill settings clearly marked.
wheel position knob ... permits the use of the entire face of the grinding wheel for maximum economy ... also used for wheel dressing.
PRECISE FEED ... you control the amount of material you want to remove from 001" to
whatever is needed to clean up a dull drill.
SHARPENING MECHANISM ... works in conjunction with
wear bushings to insure preci
The drill sharpener that gets used!
SAFETY PRECAUTIONS
- Use Safety Goggles. Safety goggles must comply with ANS Z87.1-1968. Also use face or dust mask if cutting operation is dusty.
- 2. Do not operate without guard, covers, or eyeshield.
- Do not operate with a cracked or damaged grinding wheel. Use only wheels in sound condition rated for 3600 R.P.M.
- 4. When replacing grinding wheels use only the mounting parts provided with the tool and do not overtighten.
- 5. Any damaged parts should be replaced immediately.
- Power connection must be made to the proper grounding type receptacle at voltage marked on nameplate.
- 7. Disconnect power before disassembling any part of tool.
- 8. ALL ADJUSTMENTS SHOULD BE MADE WITH MOTOR OFF AND WHEELS MOTIONLESS.
HOW TO SHARPEN A STANDARD DRILL POINT
The general purpose, or manufacturers standard drill point is the first and most important drill point to learn to sharpen correctly. It is the drill point that has the broadest range of efficient application. Once the simple techniques required
to produce this point have been mastered, other drill points to meet special needs will require only a few extra moments.
2. Set lip relief at 12°
Grinder is normally set for standard
12° lip relief (clearance) angle
1. Insert chuck into alignment fixture
4. Set drill to length
6. Loosen cam knob
- 1. Firmly press down on lever to grip
- 2. Loosen cam knob 1/2 turn.
7. Free cam
- 1. Squeeze between drill knob and cam to pull cam free of chuck seat (a distinctive "click" will be felt).
- 2. Pin stays engaged with cam and chuck should now be free to rotate within wing
9. Tighten cam knob
- 1. Firmly press down on lever to grip
- Securely tighten cam knob (do not allow chuck to turn). Cutting edges are now fixed and timed with cam.
sharp
1. Gently squeeze and hold pawls (sliding blocks).
catch on pawl steps. (Note, keep a steady pressure on chuck so that end of drill stays in contact with pawl
- Turn on motor. Insert chuck and rotate back-and-forth while holding cam lightly against post (drill will be swinging back-and
- Simultaneously turn in starts to spark (be careful not to bang drill
SHARPENING SPECIAL DRILL POINTS
In many applications a special drill point geometry can yield more economical hole production and/or longer drill life.
135° ANGLE POINT
This point is frequently preferred for hard and tough materials such as high alloy steels. Increasing the point angle in-
creases the effective rake angle of the cutting edge (lip) and reduces the length of the lip. The result is a reduction of the driving torque required to drill these materials. The feed pressures are increased. Reducing the lip relief angle strengthens the lip.
Producing this point requires only that the point angle and lip relief angle adjustments of the Darex drill sharpener be reset. Then proceed to sharpen in the conventional manner.
90° ANGLE POINT
Many soft and low strength materials, such as some cast irons, aluminum, plastic, and wood can be drilled more efficiently with a
reduced point angle. Although this change reduces the effective rake angle of the cutting edge (lip) and the length of the lip is increased, the driving torque required to drill these materials usually remains within acceptable limits. The reduced feed pressures, and the increased lip relief angle frequently permits higher feed rates.
Producing this point requires only that the point angle and lip relief angle adjustments of the Darex drill sharpener be reset. Then proceed to sharpen in the conventional manner.
CHAMFERED POINT
The chamfered point can reduce burr generation in many materials. The chamfer is also very effective in reducing wear at the
corner of the lip in abrasive materials such as cast iron or fiberglass.
The results that this point can give are well worth the few extra moments it takes to produce:
- 1. Sharpen the drill to the standard 118° point configuration in the conventional manner.
- 2. Reset the drill in the setting fixture.
- 3. Set the point angle to 90°.
- Proceed as if sharpening a 90° point angle drill but only until the desired chamfer is produced.
for applications requiring that the drill be self-centering:
Sharpen the drill in the conventional manner to produce the general purpose 118° point – then turn the feed knob counterclockwise one-half turn.
SELF-CENTERING DRILL POINT
The Darex drill sharpener can
produce an effective geometry
Reset the sharpening fixture point angle setting to approximately 115°.
- 3. Align either of the feed cam lines with the line on top of the sharpening fixture.
- With the chuck held firmly in the fixture, turn the feed knob very slowly clockwise until the wheel has cut to the center of the drill.
- Pull the chuck straight back from the wheel approximately 1/4" (6mm) and turn to align the other feed cam line with the sharpening fixture line. DO NOT DISTURB THE FEED KNOB SETTING.
- 6. While keeping the two lines in alignment, carefully push the chuck back into the fixture until the feed cam seats against its follower pin. This grinds the other side of the drill point to the correct dimensions.
- Inspect the drill point correct insufficient secondary clearance by repeating steps 3 through 6 - excessive secondary clearance is corrected by resetting the point angle to 118° and sharpening further in the conventional manner.
NOTE: This point requires considerable expertise and should only be attempted after becoming completely familiar with the machine.
POINT THINNING
Point thinning is occasionally applied to reduce the feed pressure requirements of special drills with extra heavy webs or of large drills over 3/4" (19mm). The web thickness of standard drills does not warrant this specialized practice until design life is exceeded.
The Darex drill sharpener incorporates no mechanism for point thinning. Web thinning can be preformed by the usual manual techniques on the corner of the wheel as shown.
LEFT HAND DRILLS ... A cam and pawl-block set (pt. no. 2109) is available for left-hand drills. Instructions are included with the kit.
SHARPENING CARBIDE DRILLS
Carbide-tipped and solid carbide drills can be sharpened on the Darex drill sharpener with a silicon carbide wheel available from Darex (Cat. No. 2108). The basic technique for sharpening these drills is the same as for high-speed steel drills. For best results:
- Handle carbide drills carefully. They are subject to damage from impact.
- 2. When positioning the drill in the chuck, using the setting fixture do not tighten the cam knob fully while the drill lips remain engaged with the pawls. Turn the cam knob until it lightly engages the cam. Pull the chuck back approximately 1/2" (12mm), reapply chuck brake then securely tighten cam knob. This prevents chipping of the drill lip corners.
- Begin sharpening with a newly dressed wheel. Dressing procedure is the same as for the standard wheel.
- 4. The carbide drill will not sharpen as quickly as a highspeed steel drill. Material cannot be removed as fast – and the wheel will dull more quickly. Reposition the sharpening action across the face of the wheel during sharpening.
SHARPENING SMALL DRILLS 1/16 - 5/32"
The sharpening of small drills does require more care and patience. Excellent points can be produced using the following:
- The "Wear-Bushings" and "Hinge Bearing" should be set up with minimum tolerance (see adjustments on next page).
- Remove only a few thousand at a time (it is very easy to remove to much).
- Rotate chuck quickly, with a "light-touch" to remove an equal amount from each side of drill.
After sharpening examine drill before removing from chuck – if necessary reinsert chuck into sharpening fixture to "touch-up" one lip to balance drill.
SHARPENING LARGE DRILLS 1/2 - 3/4"
It is often easier and more desirable in sharpening larger drills to use a slightly different technique.
- Proceed exactly the same way as shown on pages 2 and 3 thru step 10.
- 2. Move the drill completely off the wheel to the right.
- 3. Advance the feed knob 4 numbers (.012").
- While rotating the chuck, slowly move the drill across the wheel by turning in the WHEEL POSITION KNOB a small amount for each rotation of the chuck.
This technique removes more material yet leaves a high surface finish without burning or bluing.
WHEEL DRESSING
Wheel dressing can be kept to a minimum by repositioning drill sharpening action to different areas of the sharpening wheel face. Dress when discoloration of the drill point occurs or the face of the wheel appears glazed or grooved. To dress:
- 1. Grip the diamond dresser in drill chuck and set point angle adjustment to 135°.
- Retract the sharpening fixture by turning the feed knob counterclockwise until diamond will clear wheel when chuck is placed in fixture.
- 3. Turn positioning knob until diamond is approximately 1/16" (1,5mm) beyond right edge of wheel.
- Holding chuck and fixture firmly, apply force to move the fixture past the face of the wheel and approximately 1/16" (1,5mm) beyond the left edge.
- 5. Turn feed knob clockwise one graduation and then allow fixture and diamond to travel slowly across the face of the wheel. NOTE: Traveling too quickly across the face of the wheel will produce a "threaded" condition which results in a rough drill point finish.
- 6. Repeat steps 5 and 6 until wheel is dressed square and clean.
ADJUSTMENTS
FEED-CAM PIN ADJUSTMENT ... In the event that all drills appear to be sharpened off-center then an adjustment of the cam set-screw is necessary. To adjust, loosen lock nut and turn set screw 1/4 turn in either direction. Sharpen drill to see if off-center condition becomes better or worse, then continue adjustment until desired accuracy is obtained and tighten lock-nut.
WEAR-BUSHINGS . When excessive tolerance develops between chuck and sharpening fixture wear-bushings should be adjusted by loosening set-screw and moving bushings in. Normally only the top bushings need to be moved. DO NOT OVER ADJUST causing the chuck to bind.
HINGE BEARING ... If the sharpening swing fixture gets "sloppy" it can be adjusted by removing point angle adjustment screw exposing adjustable tapered bearing. CAUTION: Do not allow grit to enter bearing area.
SOME HINTS FOR BETTER DRILL SHARPENING
When the drill bit has been allowed to wear beyond desirable limits or is broken, do not attempt to do the whole sharpening job without resetting the drill bit in the chuck. No more than .015" – about five numbers of the graduated feed knob – can be removed at one chuck setting without beginning to adversely effect the chisel and relief angles.
When heating of the drill bit occurs during roughing or sharpening, do not cool by placing in water. Checking of the drill surfaces may occur resulting in reduced durability of the cutting edges. Allow the drill to air cool and then remove any discolored portion of the drill with continued sharpening.
The life and effectiveness of the cutting surface of the sharpening wheel can be extended by frequently repositioning the cutting action across the wheel. Repositioning before the sharpening of each drill is ideal.
The very best sharpening results are obtained with a sharp, clean wheel. Do not attempt to sharpen on a worn or glazed wheel or drill burning will result. Many dressings of the wheel are possible before replacement becomes necessary and replacement wheels are inexpensive and simple to install.
Clean this tool frequently. Use compressed air to blow grinding residue from the surfaces of the machine and the interior of the chuck. Doing this each time after wheel dressing will prolong the life of this tool.
Lubrication of this tool is not normally required. The bearings within the unit are of the self-lubricating type.
| TROUBLE SHOOTING GUIDE | |||||||
|---|---|---|---|---|---|---|---|
| PROBLEM | CAUSE | SOLUTION | |||||
| Drill off center | 1. Improper sharpening procedure |
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| A |
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| 3. Excessive dirt or dust in chuck. |
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| 1. Rotating drill too slowly. |
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| 2. Glazed wheel |
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| P) |
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| M | NOTE: Never quench drill in water after grinding or else checking and cracking of the drill point will result. | ||||||
| Negative Relief | 1. Improper relief setting |
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| 6 |
2. Drill pushed back from pawl
block while setting |
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| NEG. |
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| (i/) |
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| Drilled hole over size or | 1. Drill sharpened off-center | 1. See instructions above. | |||||
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FIG. A FIG. B
TOO STEEP BETTER / |
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| AR | 3. Work piece not clamped. | 3. Secure workpiece. | |||||
| -0-0 | 4. Excessive wear in spindle. |
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| 1. Wheel out of round | 1. Dress wheel | ||||||
| Machine Vibration | 2. Wheel wobbles |
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| Machine Vibration | 3. Bad grinding wheel | 3. Disguard wheel | |||||
| Chatter Marks | 1. Machine vibrating | 1. See above | |||||
| 0-0 | 2. Rough cam |
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PARTS LIST
| Part No. | Description | Price | Part No. | Description | Price |
|---|---|---|---|---|---|
|
5000
5001 5003 |
Motor (115V)
Motor (230V) Motor Special |
$94.00
98.00 |
5142
5144 5109 |
Arbor Spring
Comp. Ext. Spring Complete Compound Base |
3.00
2.00 60.00 |
|
5002
5172 5174 5176 5178 |
Shaft Adaptor
Seal Wheel Flange Roll Pin |
14.50
7.50 1.00 4.50 1.00 |
5112
5116 5118 5119 |
Mid-Base Frame
Felt Seals Pivot Rod Bearing Nut |
20.00
1.00 5.50 4.00 |
|
5180
5182 5101 |
Wheel Nut
Shaft Key 3/8" 16 x 1" Cap Screw |
3.00
1.00 |
5121
5124 5126 5127 |
10-24 x 3/16 Set Screw
Tapered Bearing Latch Screw Latch Clamp |
6.50
2.00 3.50 |
|
5102
5103 5104 5105 |
Wheel Guard
3/8-16 x 1-1/4 Cap Screw Wheel Guard Cover 10-24 x 5/8 Cap Screw |
18.00
8.50 |
5128
5130 5132 5133 |
Washer
Cam Follow Rod Bracket 10-24 x 1/2 Pan H.D. Sc. |
1.00
3.50 4.00 |
| 5188 | Eye Shield | - * | 5137 | Complete Mid Base | 52.00 |
| 5107 | 10-24 x 1/2 Pan Screw | 5110 | Swing Fixture Frame | 40.00 | |
| 5100 | Base | 18.00 | 5114 | Bearing Pads (8) | 10.00 |
| 5190 | Switch | 4.50 | 5115 | 10-24 x 3/16 D.P.S.C. (8) | 2.00 |
| 5242 | Motor Wire | 3.50 | 5146 | Ext. Spring | 2.00 |
| 5192 | Cord/Plug | 7.50 | 5151 | Spring Pin | 1.00 |
| 5194 | Rubber Feet | 1.50 | 5134 | Cam Pin | 1.50 |
| 5195 | Strain Relief | 1.50 | 5135 | 8-32 x 1-1/8 Oval Pt. Sc/Nut | 1.50 |
| 5240 | Fiber Cover | 2.50 | 5111 | Complete Swing Fix. | 55.00 |
| 5241 | 8-3/22 x 1/4 Self Tap Screw | * | 5113 | Complete Sharp. Ass. | 175.00 |
| 5149 | Cross Feed Screw | 4.50 | 2110 | 1/2 Chuck – Complete | 75.00 |
| 5106 | Setting Fixture Frame | 28.50 | 5205 | 1/2 Chuck Body | 12.00 |
| 5152 | Pawls L.H. (2) | 24.00 | 5210 | Jaws (4) | 8.00 |
| 5154 | Pawls R.H. (2) | 20.00 | 5212 | Closing Screw | 20.00 |
| 5156 | Pawl Block S.C. | 1.00 | 5216 | Sleeve | 8.00 |
| 5158 | Pawl Block | 12.50 | 5218 | Cam Coupler | 8.00 |
| 5157 | Pawl Block Washer | 1.00 | 5220 | Jaw Knob | 6.00 |
| 5159 | Pivot Bushing | 3.00 | 5221 | 1/4-20 x 5/16 D.P.S.C. (2) | 1.00 |
| 5161 | Pawl Knob/Screw | 5.50 | 5222 | Cam Knob | 7.00 |
| 5164 | Pawl Retaining Screws | 4.00 | 5227 | Jaw Spring (4) | 4.00 |
| 5165 | Pawl Spring | 3.50 | 5231 | Thrust Bearing | 1.00 |
| 5167 | 6-32 x 1/4 Rd. Hd. Screw/Wash. | * | 5232 | Grit Seal | 1.00 |
| 5166 | Lever Arm | 2.00 | 5234 | Seal Washing | 1.00 |
| 5168 | Lever Arm Knob | 1.50 | 5225 | Cam | 8.00 |
|
5169
5170 5107 |
Alignment Pin
Complete Setting Fixture |
2.50
85.00 |
2101
5201 5214 |
3/4 Chuck – Complete
3/4 Chuck Body |
75.00
12.00 |
| 5108 | Compound Base Frame | 35.00 | 5224 | Jaws (4) | 12.00 |
| 5120 | Flange Bearing | 3.50 | 5226 | Jaw Springs (4) | 4.00 |
| 5122 | Sleeve Bearing | 3.00 | 5223 | Cam | 10.00 |
| 5136 | Feed Knob | 6.00 | 5183 | Exh. Tube/Tool Tray | 18.00 |
| 5138 | Arbor | 10.50 | 5196 | Lamp Shade | 9.00 |
|
5139
5140 5141 5198 |
Spring Seat Wash.
Arbor Washer Arbor Seal Seal Retainer |
1.00
1.00 1.00 1.00 |
5197
5243 114 |
Cap Plugs
Shipping Box Instruction Manual |
1.00
4.50 1.00 |
* Purchase hardware items locally
700 Dixie Highway Beecher, Illinois 60401 Tel: 312/946-2216
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