Pinpoint CNC

Turret Aligment for Mori Seiki SL-25 Turning Center

pinpoint1 — Tue, 03 May 2011 04:47:59 +0000

BUILDER: Mori Seiki

MODEL: SL-25B

CONTROL: Fanuc 16-T

TITLE: TURRET ALIGNMENT (SIMPLE ROTATIONAL ALIGNMENT)

SUMMARY: THIS PROCEDURE EXPLAINS A SIMPLE ROTATIONAL ALIGNMENT OF THE TURRET AFTER AN IMPACT.

DETAILS:

After a crash, several items should be checked and noted. These are:

Headstock alignment (parallelism of the spindle centerline with the Z axis). This is done either with a test bar mounted to the spindle or more typically by cutting a part and checking the part for taper. If correction is necessary, align the headstock before performing the turret alignment. We prefer to use a part at least 1 inch in diameter (to avoid excessive part deflection) and at least 5 inches in length.
Rotational alignment of the turret. This can be done using one of two methods:
Parallelism of a turning tool pocket to the X axis movement.
Centering the bore of a boring bar holder to the spindle rotational center in the X axis plane and looking for deviation in the Y axis plane. Mount an indicator to the chuck and rotate the chuck with the indicator stylus inside the boring bar holder. (See picture 1 below).

Be sure to note the machine position of the X axis when you have positioned the X axis so that the boring bar holder is centered on the spindle. We prefer this method because if the alignment is done using this check (as opposed to aligning the turning tool pocket with the X axis movement), you will end up with the tool tips centered better on the spindle. Facing will be better as well as drilling on center. It is best to hold the indicator in a piece that is clamped in the chuck, but often times this will not be available. It is possible to use an indicator and magnetic base to do this check (see picture 1 below), but the length of this setup should be kept to a minimum to reduce sagging and only a high quality base should be used.
Parallelism of the turret bottom with the Z axis movement

Picture 1

Write down the amount and direction of any deviations from “0”.

In the case documented in this procedure, the headstock alignment and the Z axis parallelism of the turret were ok and no adjustment was necessary. However, the turret had been rotated by the impact and needed to be aligned. This is done as outlined below:

1. Position the turret so that the boring bar holder (use the best, least beat up one you can find, preferably without impact marks or scoring, rust or dents in the bore) is centered on the spindle rotational center. Make a note of the machine position in the X axis. Note the amount of deviation from “0” in the Y axis plane. (See picture 1 above)

2. Mark and remove the number plate around the center hub of the turret by taking out the Phillips screws. (See picture 2 below).

: PICTURE 2

3. Remove the 4 M8 cap screws in the turret center cover and remove the cover. (See picture 3 and 4). You may need to tap the cover in the CW and CCW direction to get it loose enough to pull out. This will expose the turret.

Picture 3

PICTURE 4

4. Remove the 2 M8 taper pins in the turret. These are located 180 degrees from each other. They are 90 degrees from the “master” pin hole. This is the hole with the small counter-bore. (See picture 5).

Picture 5

5. Loosen the (12) 8mm cap screws on the outer bolt circle. These are the bolts that hold the turret-side of the curvic coupling in place. Retighten the screws slightly (a little more than finger tight) to prevent excessive turret movement. (See picture 6).

: Picture 6

6. While watching the indicator, strike the turret to rotate it in the needed direction (CW or CCW) with a soft hammer or a piece of sturdy wood. (See picture 7) As you do this, check and adjust the X axis position back to center after seeing any change in the Y axis direction as the centerline will keep changing as the turret is rotated. Continue this process until the indicator reads “0” all the way around the inside diameter of the boring bar holder.

: Picture 7

7. Tighten the12 screws on the outside bolt circle in a cross pattern until all are fully tightened. We prefer at least 3 times around the pattern, tightening a little more each time.

Picture 8

8. Check your indicator again to make sure that the tightening of the screws did not move the turret. If you still have “0” all the way around the inside diameter of the boring bar holder, you can proceed. If not, loosen the screws and repeat from step 5. After achieving “0”, note the resulting machine position in the X axis9. After all screws are tight and your indicator reading is “0”, you will need to lightly ream the taper pin holes to remove any bur cause by the pin when the turret was impacted. (See Picture 9)

Picture 9

9. Install new taper pins. Use only the correct size metric taper pin with a tapped hole for later removal. Put a screw into the tapped hole in the pin and lightly strike the screw with a small hammer to seat the pin.

10. Check the rotational alignment with the indicator one more time with the indicator to make sure the turret is still correctly aligned.

11. Reinstall the center cover and the number plate.

12. Using the machine position of the X axis from step 8, calculate the difference between the current X centerline position and the machine specification distance. You will need to adjust the X axis grid shift to get the distance from X zero-return (home) position to the spindle centerline back to the specification distance. The specification distance may vary depending on the machine model and number of turret stations.See below:

Model: SL-25A, 25B, 25MC

10 Station Turret: 250mm or 10 inches

12 Station Turret: 250mm or 10 inches

Using the calculation from step 13, calculate the X axis grid-shift needed to put the machine back to specification. Use the following as a guide and you can be successful on your first attempt:

GRID SHIFT

Grid Shift is another element that must be considered to fully understand how the CNC establishes axis home position. Grid shift is a value entered into a CNC parameter that electronically phase-shifts the data coming from the motor’s encoder.

When a grid shift value is entered, the reference counter in the CNC no longer “sees” the native encoder data. The reference counter “sees” only the phase-shifted data.

By using this parameter, the machine’s ZRN stop position can be easily adjusted.

INCH-TO-METRIC CONVESIONS

Millimeters (mm)	Microns (m)	Inches (in)
25.4	25,400	1
1	1000	0.0394
.001	1	0.0000394
.0254	25.4	.001
.00254	2.54	.0001

Value in prm #1820	D.U.	Multiplier to get 1 micron value
10	.2	5
20	.1	10
4	.5	2
2	1	1

DETECTION UNIT CALCULATION

Since the parameters for grid shift and backlash are in detection units, it is important to know how to calculate the detection units for each axis on the machine. Note that the detection unit may not always be the same for all axes on a machine.

To do this, check parameter #1820 (CMR – command multiply ratio), and use it in the following formula:

2m /prm1820 = detection unit (D.U.)

EXAMPLES:

Value in prm #1820	D.U.	Multiplier to get 1 micron value
10	.2	5
20	.1	10
4	.5	2
2	1	1

GRID SHIFT CALCULATION EXAMPLE

Example:

Suppose you have determined that an axis needs to be grid-shifted in the positive (+) direction by 0.030in. First, you must convert this error into a micron value.

30 X 25.4 = 762m

Then, you must determine the detection unit. Let’s say that parameter #1820 = 10.

2m/10 = .2m

Thus, the detection unit is .2m

To find the number to be added to parameter #1850 which would equal 762 microns, solve for “A” in the formula below:

762m = A X .2

762m/.2 = A

3810 = A

Thus, we would add 3810 to the existing grid shift value.

PWE (parameter write enable) will need to be on to change the parameter and the machine must be in M.D.I. After changing the grid-shift parameter (1850 for X axis), you will be prompted to shut off the control. Do this and wait several seconds and turn it back on. Let the machine power on fully. You should see and “alarm 300 X axis needs zero return”.

Zero-return the X axis then bring the boring bar down in the X axis until the machine position is the specification distance (X -10.0000”). When the indicator mounted to the chuck is rotated inside the boring bar at this position, your indicator should read “0” as in step 8. If not, adjust the X axis position until the boring bar holder is concentric with the spindle rotation (indicator reads “0” all the way around) then recalculate the grid shift based on the new X axis machine position. If you achieve “0” all the way around the boring bar holder at the machine specified distance (X-10.0000”) the turret alignment is complete.

For Machine Tool Parts and Accessories, go to www.globalmachineparts.com

Free CNC Alarm Information at www.cncalarm.com

For information on Toyooki products, go to www.toyookivalve.blogspot.com

Go to www.industrialfanslink.com for information on Industrial Fans for Machines.

For machine scraping, alignment and repair check out Geometric Specialties

Go to www.industrialoilcooler.com for information on Industrial Oil Coolers and Chillers

Looking for New and Used Fanuc Parts? Go to www.fanucshop.com

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CNC Repair Procedure: How to Disassemble the Turret Clamp/ Unclamp Piston on a Fuji HM-30 CNC Milling Machine (Alarm 1002 Turret Clamp/ Unclamp Time Over)

pinpoint1 — Mon, 02 May 2011 04:40:12 +0000

BUILDER: FUJI

MODEL: HM-30

CONTROL: FANUC 21iM

TITLE: TURRET INDEX TIME OVER ALARM. TURRET NOT FULLY UNCLAMPING.

SUMMARY: CORROSION IN THE BORE FOR THE TURRET UNCLAMP PISTON PREVENTED FULL UNCLAMPING. CLAMPING CYLINER NEEDED TO BE REMOVED.

ALARMS: 1002

DETAILS:

Index turret to station 1 and make sure it’s clamped. If the motor will not rotate the turret, you can look at the tool-driver to make sure you are in the correct location. The friver should be centered on the hole at the turret station at the 9 o’clock position. You can then use the solenoid valve to clamp.

2. Mark and remove all holders from turret

3. Remove the front-end covers upper and lower sections

4. Disconnect the coolant pump at connector 1M2 at the rear of the machine.

5. Remove the split-ring guard on the turret. It makes it easier to handle when the turret comes off.

6. Remove the outer bolt pattern (M10 screws) that hold the turret on. Remove the eccentric pin prior to taking the turret off.

7. Remove the back section of the way-cover.

8. Remove the (2) M6 screws holding the clamp/unclamp proximity switches. Mark the bracket mounting location. Remove the (2) M8 screws holding the electrical connection box in place. You will need to move this out of the way.

9. Remove the (4) hex bolts that mount the turret-index motor. Set the motor and the box down inside the back area.

10. Remove the air hose for the oil-air mist.

11. Loosen the (3) set-screws and then remove the KMT nut from the back of the shaft. Remove the switch dog. Suggestion: take and record several measurements to make sure you get everything back the way it was to begin with when you re-assemble.

12. Loosen the M8 screws in the face of the Mecha-lock. Remove the Mecha-lock from the bore in the gear.

13. Push the shaft forward about ½ inch to make some room on the back side for the removal of the gear and the back cover.

14. Remove the M8 screws from the back cover. Be careful not to lose the small lock washers on the screws. The cover must be pulled straight back as there are (2) pins in the bottom edge. Take off the large gear.

15. Remove the front disk and shaft from the front side. This will expose the machine-side coupling and the front end of the piston. Set it carefully on the floor. Watch that you catch the bearings on the back as the shaft comes out.

16. Remove the M8 screws that hold on the back cylinder flange. You can put a small screw in one of the tapped holes and gently pry the flange out of the bore.

17. The piston can now be removed. It will probably be necessary to hammer it out. Care must be taken to avoid damaging the piston or the cylinder bore. A tool can be made from scrap round-stock for this purpose.

For Machine Tool Parts and Accessories, go to www.globalmachineparts.com

Free CNC Alarm Information at www.cncalarm.com

For information on Toyooki products, go to www.toyookivalve.blogspot.com

Go to www.industrialfanslink.com for information on Industrial Fans for Machines.

For machine scraping, alignment and repair check out Geometric Specialties

Go to www.industrialoilcooler.com for information on Industrial Oil Coolers and Chillers

Looking for New and Used Fanuc Parts? Go to www.fanucshop.com

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Hydraulic Solenoid Valves and Simple Circuit Diagram

pinpoint1 — Wed, 23 Mar 2011 02:26:08 +0000

Please read the “TERMS OF USE” for this site before proceeding.

This post will be the first of several discussing hydraulics as used on a machine tool. We’ll go basic to start with.

You might have many hydraulic functions on your machine or just a few.

On a lathe you would typically see some of the following tasks of a machine actuated using hydraulic cylinders or actuators:

chuck open/ close
turret clamping
turret indexing (on older machines, anyway)
tailstock quill in/out
clamping of a programmable tailstock

On a milling machine:

spindle tool clamp/ unclamp
B axis clamping
magazine indexing (older machines)
gravity axis counter-balance

For this post, we will discuss just a few basics that may help you get an understanding of the hydraulic circuit diagram for your machine and a little about solenoid valves.

The heart of the hydraulic system on a machine is the pump/motor unit (or hydraulic unit). This provides pressurized fluid (through piping and hoses) to the actuators of the machine. The actuators provide the actual mechanical motion needed to perform tasks (as mentioned above).

Valves (typically solenoid controlled valves) direct the fluid to the actuators at the appropriate time to perform actions (i.e. chuck open or close). A coil is electrically energized and a magnetic field is created. This magnet shuttles the valve spool. This change of position of the spool redirects the pressurized fluid to the appropriate actuator or cylinder side.

This is a drawing of a solenoid valve:

This is a 4-way, 3-position directional valve. 4-way refers to the 4 ports or connection points on the body of the valve: P, T, A, B.

P=Pressure
T=Tank
A=Fluid path to side A of an actuator
B=Fluid path to side B of an actuator

3-position refers to the 3 possible operating positions of the valve. Each position (or circumstance) is represented by one of the 3 squares in the diagram.

The LH square represents the circumstance when solenoid A is energized:

Port A is connected to Pressure
Port B is connected to Tank (or return to tank)

The RH square represents the circumstance when solenoid B is energized (which happens to be the opposite condition of the LH square):

Port A is connected to Tank (or return to tank)
Port B is connected to Pressure

The Center square represents the circumstance when neither solenoid A or B is energized. In this case, spring pressure returns the spoool to the center position:

P is connected to T
Both ports A and B are blocked

This diagram pertains to the particular solenoid valve in our example. The diagram will be different based on the different types of valves used in a machines. A valve will typically have this type of diagram on the valve its self, so it is possible to see what happens to the fluid path under the different circumstances than can occur.

Below is a sample hydraulic diagram. It contains the same type of solenoid valve discussed above. It also shoes symbols for some typical components found in a hydraulic circuit diagram. In this example, the valve is being used to control the rod extend/ retract motion of a cylinder.

When solenoid A is energized (LH square):

Pressure is connected to port A.
Pressurized fluid enters the rod-side of the cylinder, causing the rod to retract.
Fluid in the blind-side of the cylinder is pressed out and is provided a path to return to Tank.

When solenoid B is energized (RH square):

Pressure is connected to port B.
Pressurized fluid enters the blind-side of the cylinder, causing the rod to extend.
Fluid in the rod-side of the cylinder is pressed out and is provided a path to return to Tank.

When neither solenoid A or solenoid B are energized (Center square):

Spring pressure moves the spool to the center position.
Pressure is connected to Tank.
Both ports A and B are blocked.
The cylinder rod does not extend or retract.

For Machine Tool Parts and Accessories, go to www.globalmachineparts.com

Free CNC Alarm Information at www.cncalarm.com

For information on Toyooki products, go to www.toyookivalve.blogspot.com

Go to www.industrialfanslink.com for information on Industrial Fans for Machines.

For machine scraping, alignment and repair check out Geometric Specialties

Go to www.industrialoilcooler.com for information on Industrial Oil Coolers and Chillers

Looking for New and Used Fanuc Parts? Go to www.fanucshop.com

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