5.1 Maintenance

HKM-1 - Maintenance

Under Construction

Maintenance

Maintenance Item Interval

Check the oil level of the lubrication pump

 Daily (or before use)
Check coolant level Daily (or before use)

Let machine idle for 3-5 minutes before operations

 Daily (or before use)
Grease head Daily (or before use)

Clean work table 

 Daily (end of workday)
Return sliding components to home position. Restore head to upright position. Daily (end of workday)
Remove tool from spindle Daily (end of workday)
Oil head Twice per week
Clean and oil linear guides. Check that work table moves smoothly in all directions.  Monthly
Check function of brakes and belts Quarterly
Check level of work table and alignment of head  Quarterly
Change lubrication oil Quarterly

Fill Coolant and Lubrication

Note: Machine does not come with oil or coolant. Oil and coolant must be purchased seperately. 

1

Remove the cap [1] to access lubrication fill port. Pour oil slowly, giving it time to pass through the filter. Fill until oil approaches max fill line. 

Lubrication tank should be filled with 93-4578 SYNTHETIC GEAR/BEARING OIL 1GL/3.78L, or 93-2365 SYNTHETIC GEAR/BEARING OIL 1QT/0.94L, or an ISO VG68 Oil. About 2 quarts is needed to fill the tank.

To modify the discharge volume of lube, loosen the set screw [2]. Turn the nut counterclockwise to decrease volume and clockwise to increase volume. The increments [3] on the post indicate discharge volume.  

2

The lubrication system must be manually primed. Pull up on the plunger [1] and release it. Wait until the plunger returns to it's initial position. Pull and release at least twice more. Do not press on the plunger. 

 

3

Remove the coolant tank cover from the back of the knee mill column by unscrewing the four bolts [1]. Fill the coolant tank.

Note: Ensure that coolant tank is clean and free of chips before filling coolant. 

For more information about coolant mixing and concentrations, see Coolant - Overview and Coolant -Maintenance .

 

Note: Be sure to maintain your coolant mixture to keep the coolant concentrate at acceptable levels. Improperly maintained coolant mixtures can allow machine components to rust. Rust damage is not covered by your warranty. Ask your HFO or your coolant dealer if you have questions about the specific coolant you plan to use. 

Grease and Oil Head

1

The three ports [1] on the head of the machine should be filled with 93-4575 SYNTHETIC GEAR/BEARING OIL 1GL/3.78L, 93-2365 SYNTHETIC GEAR/BEARING OIL 1QT/0.94L, or other ISO VG68 Oil. 

 

The grease port [2] should be filled with 93-3891 GREASE MOBIL XHP 322 5% MOLY or other EP32 grease. 

5.2 Replace Motor

Dismantle Motor

Start the motor and turn the speed dial to 2100 RPM.

1

Switch off mill and unplug from power source. Remove junction box cover. Disconnect the brake switch wiring [1] and cables U, V and W [2]. Disconnect ground [3]. 

Pull conduit out of J-box. 

 

Note: Record the wiring configuration of your J-box. If it differs from the example given, disregard the example and re-wire according to your notes. 

2

 Remove three bolts under bearing housing [1]. Insert a flathead screwdriver into each of the gaps in the bearing housing. Lever the bearing housing off of the bearing by pushing down on both screwdrivers at the same time. 

3

Use a flat head screwdriver to remove the bearing [1]. Lever the screwdriver against the slightly wider section of the motor shaft [2]. Levering it against the spring will not provide sufficient leverage. 

4

Use two M6 x 45 bolts [1] to tension the spring. Remove the snap ring [2] from the motor.

5

Remove the bolts on the motor [1]. Change the motor speed to 4200 RPM. 

Pull up to remove the motor. A second person may be helpful to guide the motor out of the casing and ensure that the belt does not get stuck on the shaft. 

Replace Motor

1

Place concave plates [1], tensioning spring, and snap ring [2] on motor shaft. 

2

Loosely loop a zip tie around the speed change belt. Pull on speed change belt to create slack.

3

Lower motor to 1-2 inches above the motor casing. Use zip tie to pull belt up and around the bottom concave plate. 

Rotate motor shaft by hand while pulling the zip tie up and around in the same direction to ease belt in between concave plates.

 

 

4

Lower motor into casing. Snip and remove zip tie before setting motor down. Bolt motor into place [1].

 

 

5

Remove bolts from speed change spring. With a rubber mallet, lightly hammer bearing into place on bottom of motor shaft. Rotate shaft continuously to ensure that bearing does not become crooked. 

 

6

Place wave ring in bearing housing. Push bearing housing into bearing, and lightly hammer with rubber mallet until bearing housing is within 0.5" of the motor casing. 

Continue to push housing onto bearing by incrementally tightening housing bolts [1].

 

7

Re-wire J-box.

 

Note: If the initial wiring of your J-box differs from the example, ignore the example and re-wire according to the initial wiring of your J-box. 

5.3 Replace Speed Change Belt

Dismantle Motor

Start the motor and turn the speed dial to 2100 RPM.

1

Switch off mill and unplug from power source. Remove junction box cover. Disconnect the brake switch wiring [1] and cables U, V and W [2]. Disconnect ground [3]. 

Pull conduit out of J-box. 

 

Note: Record the wiring configuration of your J-box. If it differs from the example given, disregard the example and re-wire according to your notes. 

2

 Remove three bolts under bearing housing [1]. Insert a flathead screwdriver into each of the gaps in the bearing housing. Lever the bearing housing off of the bearing by pushing down on both screwdrivers at the same time. 

3

Use a flat head screwdriver to remove the bearing [1]. Lever the screwdriver against the slightly wider section of the motor shaft [2]. Levering it against the spring will not provide sufficient leverage. 

4

Use two M6 x 45 bolts [1] to tension the spring. Remove the snap ring [2] from the motor.

5

Remove the bolts on the motor [1]. Change the motor speed to 4200 RPM. 

Pull up to remove the motor. A second person may be helpful to guide the motor out of the casing and ensure that the belt does not get stuck on the shaft. 

Dismantle Speed Change Belt Assembly

1

Remove drawbar cover [1].

2

Disconnect pneumatic lines from drawbar actuator [1].

3

Unbolt drawbar actuation assembly [1].

4

Insert bolts from drawbar actuation assembly into specified holes on the bearing housing. Tighten the bolts incrementally in a star pattern to lift the bearing housing pins [1]. Remove bearing housing [2].

5

Remove bolts and bolt sleeves [1] from speed change bracket.

6

Remove bolts under gear housing [1]. Lift off gear housing. Speed change belt can now be removed and replaced. 

 

Rebuild Speed Change Assembly

1

Replace gear housing. Replace sleeves and bolts on speed change housing [1]. 

 

Using a screwdriver or other long tool, press upwards under the top concave plate to ensure that it is all the way at the top of the shaft. 

2

Replace bearing housing. Tighten bolts in a star pattern [1]. 

Replace drawbar actuator and pneumatic lines. 

Replace drawbar cover. For information on re-installing the motor, see Replace Motor section above. 

Replace Motor

1

Place concave plates [1], tensioning spring, and snap ring [2] on motor shaft. 

2

Loosely loop a zip tie around the speed change belt. Pull on speed change belt to create slack.

3

Lower motor to 1-2 inches above the motor casing. Use zip tie to pull belt up and around the bottom concave plate. 

Rotate motor shaft by hand while pulling the zip tie up and around in the same direction to ease belt in between concave plates.

 

 

4

Lower motor into casing. Snip and remove zip tie before setting motor down. Bolt motor into place [1].

 

 

5

Remove bolts from speed change spring. With a rubber mallet, lightly hammer bearing into place on bottom of motor shaft. Rotate shaft continuously to ensure that bearing does not become crooked. 

 

6

Place wave ring in bearing housing. Push bearing housing into bearing, and lightly hammer with rubber mallet until bearing housing is within 0.5" of the motor casing. 

Continue to push housing onto bearing by incrementally tightening housing bolts [1].

 

7

Re-wire J-box.

 

Note: If the initial wiring of your J-box differs from the example, ignore the example and re-wire according to the initial wiring of your J-box. 

5.4 Replace Timing Belt

Dismantle Motor

Start the motor and turn the speed dial to 2100 RPM.

1

Switch off mill and unplug from power source. Remove junction box cover. Disconnect the brake switch wiring [1] and cables U, V and W [2]. Disconnect ground [3]. 

Pull conduit out of J-box. 

 

Note: Record the wiring configuration of your J-box. If it differs from the example given, disregard the example and re-wire according to your notes. 

2

 Remove three bolts under bearing housing [1]. Insert a flathead screwdriver into each of the gaps in the bearing housing. Lever the bearing housing off of the bearing by pushing down on both screwdrivers at the same time. 

3

Use a flat head screwdriver to remove the bearing [1]. Lever the screwdriver against the slightly wider section of the motor shaft [2]. Levering it against the spring will not provide sufficient leverage. 

4

Use two M6 x 45 bolts [1] to tension the spring. Remove the snap ring [2] from the motor.

5

Remove the bolts on the motor [1]. Change the motor speed to 4200 RPM. 

Pull up to remove the motor. A second person may be helpful to guide the motor out of the casing and ensure that the belt does not get stuck on the shaft. 

Dismantle Speed Change Belt Assembly

1

Remove drawbar cover [1].

2

Disconnect pneumatic lines from drawbar actuator [1].

3

Unbolt drawbar actuation assembly [1].

4

Insert bolts from drawbar actuation assembly into specified holes on the bearing housing. Tighten the bolts incrementally in a star pattern to lift the bearing housing pins [1]. Remove bearing housing [2].

5

Remove bolts and bolt sleeves [1] from speed change bracket.

6

Remove bolts under gear housing [1]. Lift off gear housing. Speed change belt can now be removed and replaced. 

 

Replace Timing Belt

1

Remove top plate from timing gear [1]. Pull belt off of timing gear. 

2

Remove snap ring from drawbar shaft [1]. Lift off top concave plate [2]. 

3

Unbolt brake housing [1] and lift off brake assembly. The timing belt may now be removed and replaced.

5.5 Adjust Backlash

Adjust Y-Axis Lead Screw

1

Remove two bolts on the table [1] and the front of the knee [2]. Remove the front way cover. 

2

 Turn the y-axis crank counterclockwise to move the saddle to the front of the knee.

Remove the four bolts [1] on the y-axis bearing bracket. 

3

Engage the Y-axis lock [1]. Turn the y-axis handle clockwise [2] while supporting the bearing braket. The pins will seperate from the saddle. 

 

4

Extrude the ballscrew until the ballscrew adjustment tool can fit into the housing. Insert the larger side of the ballscrew adjustment tool into the saddle until it touches the lock nut. Rotate the adjustment tool around the ballscrew until both halves slide into the slots on the lock nut. 

Turn the adjustment tool once counterclockwise to loosen the lock nut. 

5

 Insert the smaller side of the lead screw adjustment tool into the saddle. Rotate the adjustment tool around the lead screw until both halves slide into the slots on the adjusting nut. 

Turn the adjustment tool to adjust the preload on the lead screw. Test the backlash by turning the axis handle. Adjust the preload until the backlash is between 0.003-0.005" (0.08 to .13 mm). Tighten the lock nut. 

 

 

6

While supporting the y-axis bearing bracket [1], turn the y-axis handle counterclockwise to retract the lead screw. Re-install the bearing bracket and way cover.  

 

Adjust X-Axis Lead Screw

1

Move the table to the center of the y and x axes. Insert the larger end of the adjustment tool under the left side of the table. Rotate the tool once counterclockwise to loosen the lock nut. 

2

 Insert the smaller side of the lead screw adjustment tool into the saddle. Rotate the adjustment tool around the lead screw until both halves slide into the slots on the adjusting nut. 

Turn the adjustment tool to adjust the preload on the lead screw. Test the backlash by turning the axis handle. Adjust the preload until the backlash is between 0.003-0.005" (0.08 to .13 mm). 

Tighten the lock nut. 

 

5.6 HKM-1 Service Parts List

Part Number Description Applies to Machines
93-4884 Belt, Variable Speed HKM-1
93-4885 Belt, Timing HKM-1
93-4886 Brake Shoes HKM-1
93-4887 Brake Shoe Spring HKM-1
93-4888 Quill Clock Spring & Cover Z-Axis HKM-1