background image

Snap-on • 17

Figure 21 – Tool bit controls

9.

Turn the cross feed handwheel until the tool bits

are at mid-point of the rotor face.

10.

Turn the left hand tool bit control until the tool

bit contacts the rotor surface and makes a scratch cut.
After the cut is made, back the tool bits off and turn
the lathe OFF.

Figure 22 – First scratch cut

The scratch will usually appear as an incomplete cir-

cle. This is caused by runout or wobble due to rotor
condition, or by the way the rotor is mounted on the
arbor.

11.

Check rotor mounting by loosening the arbor

nut and turning the rotor 180° by hand on the arbor.
Make sure the inside adapter does not rotate along
with the rotor. Then retighten the arbor nut, turn the
cross feed handwheel back 1/2 turn, turn the lathe
ON, and repeat step 10 to make a second scratch cut.

Figure 23 – Rotate rotor 180°

Figure 24 – Second scratch cut

12.

If the scratch cuts are side-by-side, the runout

or wobble is caused by rotor condition. A dial indicator
may be used to compare rotor runout with manufac-
turer’s specifications.

Figure 25 – Using a dial indicator

13.

If the scratch cuts are opposite one another

(180°), the rotor may not be properly mounted on the
arbor. Remove the rotor and examine the arbor and all
adapters for nicks, burrs, chips, dirt, or rust. Inspect
the rotor hub for loose or damaged bearing cups.
Clean, repair, remount, or replace as necessary.

Brake Lathes

Inner depth-of-
cut collars

Tool bit controls

Hold knob with one hand

– turn collar

Each increment =

0.002” english,

0.05 mm metric

First scratch cut

Rotate rotor only 180°

Loosen arbor
nut, do not turn
inside adapter

Second
scratch cut

Scratch cuts
opposite each
other

Dial indicator

Summary of Contents for EEBR312A

Page 1: ...ating Instructions Safety Instructions Maintenance Instructions READ these instructions before placing unit in service KEEP these and other materials delivered with the unit in a binder near the machine for ease of reference by supervisors and operators ...

Page 2: ...harp and clean for best and safest performance Follow instructions for lubricat ing and changing accessories 19 Remove power from the unit and disconnect tools before servicing and when changing accessories such as blades bits cutters etc Follow lock out and tag out proce dures as required 20 Avoid unintentional starting Make sure the switch is in the OFF O position before plugging the machine in ...

Page 3: ...c Operation 9 Spindle 9 Spindle Feed 9 Spindle Speed 9 Spindle Speed Adjustment 9 Cross Feed 9 10 V Belt Tension and Adjustment 10 Basic Operation of Handwheels 10 Reconditioning Brake Drums 11 Preparation 11 Mounting Drums 11 13 Typical Drum Mounting Configurations 12 Reconditioning Disc Brake Rotors 14 Preparation 14 Rotor Mounting 14 Model 6950 Twin Cutter 14 Typical Rotor Mounting Configuratio...

Page 4: ...e and face equipment is required to be used where there is a reasonable probability of injury that can be prevented by use of such equipment OSHA 1910 133 a Protective goggles safety glasses or a face shield must be provided by the purchaser user and worn by the operator of the equipment Make sure all eye and face safety precautions are followed by the operator s Keep bystanders out of the area 2 ...

Page 5: ...fully inspect the unit on a regular basis and perform all maintenance as required Service and maintain the unit only with authorized or approved replacement parts Keep all instructions permanently with the unit and all decals labels notices on the unit clean and visible Do not override safety features Definitions of Hazard Levels Identify the hazard levels used in this manual with the following de...

Page 6: ...ectrical power tool only Do not modify a cord or plug to match a receptacle have a qualified electrician install an appropriate outlet to match the lathe require ments Repair or replace any worn or damaged power cords immediately Verify that the lathe plug and grounding type recep tacle match as shown in Figure 1 Figure 1 Power Cord Plug and Receptacle Types Installation 1 Assemble bench according...

Page 7: ...875 251 mm Spindle speed Inner groove 60 RPM Middle groove 80 RPM Outer groove 115 RPM Spindle feed speed Infinitely variable Minimum 0 002 inch per revolution 0 05 mm rev Maximum 0 020 inch per revolution 0 50 mm rev Cross feed speed Fine 0 002 Course 0 010 Handwheel graduations 0 002 0 050 mm Maximum brake rotor diameter 14 5 368 3 mm Maximum brake rotor thickness 1 875 47 63 mm Brake drum diame...

Page 8: ...eed Handwheel Spindle Feed Dial Spindle Feed Engaging Lever Spindle Lock Oil Dipstick Cross Feed Engaging Lever Cross Feed Gearbox V Belt Speed Adjusting Lever Belt Tension Adjusting Nut ON OFF Switch Infimatic Variable Feed Gearbox Assembly Draw Bar Drive Motor Pulley Guard Principle Operating Parts ...

Page 9: ...is a motor driven shaft that turns the arbor upon which the brake drum or rotor is mounted By turning the drum and holding a cutting tool against the inner braking surface metal can be removed Do not try to move any feed levers or dials without the drive motor running Damage may occur to the gear trains Spindle Feed By operating the spindle feed lever the spindle will move the mounted brake drum t...

Page 10: ...n 2 Loosen the adjustment nut Figure 5 Engage lever and loosen nut 3 Push in on the belt approximately 1 4 to 1 2 0 64 to 12 7 mm and hold 4 Retighten the adjusting nut Figure 6 Press the belt in and tighten adjusting nut Basic Operation of Handwheels Clockwise rotation of the spindle feed handwheel retracts the spindle in towards the lathe Clockwise rotation of the cross feed handwheel moves the ...

Page 11: ...ng their respective handwheels to their maximum clockwise in position Then back off the cross feed handwheel 2 complete turns and the spindle handwheel 4 complete turns 5 Position the boring bar by loosening the boring bar clamp nut and sliding the boring bar inward toward the drum until the tool bit is close to the drum The boring bar position is changed whenever a drum of different diameter is m...

Page 12: ...straddle the boltholes to avoid mounting against a burr or remove the burrs Slip the hubless adapter onto the arbor followed by a spring the cone the drum and another hubless adapter Fill out the shaft with spacers as needed Key to MountingAdapters Cones and Related Parts A 1 Arbor B Flange Plate C Spring D Centering Cone E Rotor Drum or Flywheel F Flange Plate G Spacer s H Self Aligning Spacer I ...

Page 13: ...oximate reconditioned diameter of the drum This measure ment must be compared with A The maximum rebore limits cast into the drum B The measured diameter to determine the best amount of material to be removed in one pass 18 Determine the depth of cut by these general guidelines Roughing cuts should be no deeper than 0 020 Finish cuts should be no shallower than 0 004 deep 19 With the lathe running...

Page 14: ...embly Tighten the nut firmly Figure 16 Install the twin cutter Rotor Mounting Review the descriptions of mounting a brake drum on page 12 and the illustrations of typical rotor mount ing configurations on page 15 The same directions apply when mounting a brake rotor Hubbed rotors are mounted on adapters that fit into the bearing races Hubless rotors use a cone in the center hole and a hubless adap...

Page 15: ...e Lathes 1 Arbor Arbor Nut Self Aligning Spacer Spacer Spring Flange Plate Flange Plate Centering Cone Small Double Taper Adapter Large Double Taper Adapter Adapter Used as Spacer Typical Rotor Mounting Configurations ...

Page 16: ... rotor will produce flying chips and debris Figure 19 Attach the safety shield 4 Adjust the drive belt to match the rotor size Use the outer pulley groove for passenger car and most light duty truck rotors Choose one of the inner pulley grooves when machining medium duty and larger truck rotors and some solid rotors Figure 20 Adjust drive belt location 5 Make sure that the tool bits clear the roto...

Page 17: ... 2 turn turn the lathe ON and repeat step 10 to make a second scratch cut Figure 23 Rotate rotor 180 Figure 24 Second scratch cut 12 If the scratch cuts are side by side the runout or wobble is caused by rotor condition A dial indicator may be used to compare rotor runout with manufac turer s specifications Figure 25 Using a dial indicator 13 If the scratch cuts are opposite one another 180 the ro...

Page 18: ...omatic cross feed by moving the lever to the desired speed The cross feed will stop automatically when the cutting tools have moved all the way across the face of the rotor Note For roughing cuts move the cross feed lever to the FAST position Figure 26 Engage auto matic cross feed Maintenance and Service Oiling The lathe is shipped from the factory with the cor rect amount and type of oil Check oi...

Page 19: ...ers from the arbor after recondi tioning a drum or rotor and wipe them clean espe cially the inboard adapter When a finished drum or rotor is removed from the arbor the inboard adapter may move slightly away from the face of the arbor and allow metal chips to fall into the opening causing a poor mounting for the next drum or rotor Regularly inspect the faces and seating tapers of the adapters for ...

Page 20: ...eatures by other than Seller s authorized representatives D improper or negligent use application operation care cleaning storage or handling E fire water wind lightning or other natural causes F adverse environmental conditions including without limi tation excessive heat moisture corrosive elements dust or other air contaminants radio frequency interference electric power failure power line volt...

Reviews: