[DarkStarMedia]

So I have this weird issue with rigid tapping... It seems to start ok but then turns slowly (like it's trying to index) and then the spindle times out.

Now, I know the encoder is ok because it orents just fine for tool changes.

My machine is a 8000 rpm high speed spindle (no gearbox) so I don't know if that has anything to do with it.

See attached video (TURN OFF SOUND!!).... sorry about the compressor...

Any thoughts? Here is the code used:

N480;JOB 1 TAP RANDOM POINT PATTERN
N490;FEATURE DRILL TAP
N500T3M06
N510M01
N520S100M03
N530G00G54X3.6633Y1.5859Z0.1
N540M08
N550S100M03
N560G95M29
N570G84X3.6633Y1.5859Z0.7F0.0625
N580Y-1.5859
N590X7.75Y-2.3876
N600Y2.3876
N610G94M28
N620G80
N630M05
N640M09
N650G00G90

Richard

Video: http://www.darkstarmediallc.com/brid...igtap_fail.mp4

[forhire]

Remove the G94 ahead of the M28 and set your RPM higher. I normally don't tap slower that 300 RPM. What size tap is this?

You may need to move G95 above your spinde start. Maybe it's confused?

Also, try in G94 (IPM) mode instead of G95 (IPR).
G94
S300M03
M29
G84X3.6633Y1.5859Z0.7F18.75
M28

[DarkStarMedia]

Ok... I think I figured this out and it's all about tuning. after a conversation with EMI it was likely that my spindle drift was off.

Here is the test.

in the mdi give the machine a s0m3

If the spindle is moving greater than 1 rpm (or really at all) you need to adjust the drift...

Here is the procedure from EMI:

Spindle Tests

1) Spindle Drift
Checks the spindle speed drift when a spindle speed of 0 RPM is commanded.

Using Maintenance Page, command a spindle speed of 0 rpm. Select MDI by pressing the F2 key, and enter “S0M3”. The spindle should not rotate at more than 1 rpm. Adjustments to spindle drift are done at the spindle drive. In the VMC 760 / 800 / 1000, drift is nulled out at the Siemens Spindle Drive (see the relevant page from the maintenance manual, at the end of this document). In the TorqCut 22/30, and TC1-4, drift is nulled out at the Yaskawa Spindle Drive (see the relevant page from the maintenance manual, at the end of this document). For the Yaskawa drive, if needed, Tech Bulletin


there were pictured in the service bulletin that showed how to change the setting in the Yaskawa drive but its pretty simple.

on the drive press the "disp" button to get to "C1" section

Press the right arrow key to go to the right set of numbers (it will be on 01)

Use the up arrow key to change it to "11" so the display reads "C1-11"

Press the data key to display the current setting

with someone watching the spindle movement (or go back and forth your self) change the number by one (up or down) and hold the data key for a second or so and it will activate the new data.

if the spindle moved faster, you went the wrong way.

Rinse and repeat. it is rather sensitive so it's really not necessary to move it a lot at each step.

on my machine, in the maintenance menu had up, I started at an rpm that hovered between -4 and -5 rpm.

the C1-11 setting on my drive was set at -4. after going back and forth a few times I ended it at a setting of 1.

Now my spindle stays put and just twitches slowly a bit.

He also gave me instructions for tuning rigid tapping to reduce wear on taps and provide better holes (adjusting spindle gain).

If you are interested I can post that too.

Richard

[forhire]

Now my spindle stays put and just twitches slowly a bit.

He also gave me instructions for tuning rigid tapping to reduce wear on taps and provide better holes (adjusting spindle gain).

If you are interested I can post that too.

Interesting. Clearly mine has been tuned correctly. Thanks for posting this procedure of dialing it in as I'm sure others (myself included) will need this at some point.

I would be interested in the tuning procedures.

[DarkStarMedia]

here is what it said about rigid tap tuning:

4) Rigid Tap Test
Verify that the spindle is tuned properly for rigid tapping operations.
Copy the following program into the machine and save it as ‘longtap.txt’.

s1000g95m29
l1
g84u0.0z6.0f0.1
=l1

Load it and setup to run as follows:
Remove any tool that is in the spindle. To allow adequate clearance, move the head to the top of the
machine. Run the program under the Maintenance Page diagnostic software. Press the F5 key on the
screen where the axis drives are enabled. Reset the program, set mode to Auto, and press Cycle
Start. The machine will execute a 6” depth rigid tapping cycle from where the Z-axis is sitting.

Watch the DRO S-Axis POS-ERR. If it is greater than 1 degree adjust Parameter 64
(S [5th] Axis Velocity Gain).

Parameter adjustment:
During (+) positive rotation, the S-axis DRO POS-ERR must be (+) positive; increase Parameter 64.
During (–) negative rotation, the S-axis DRO POS-ERR must be (-) negative; increase Parameter 64.
If the sign of the POS-ERR is opposite of the rotation direction, decrease Parameter 64.

Note: the POS-ERR will spike during reversal; ignore this. The read-out is only valid when the DRO /
POS-ERR is stable.


EDT: The other thing they noted that is if parameter 64 is off enough to get a spindle time out error you can change parameter 194(?) which is your spindle ramp up time to 5000. instead of waiting 5 seconds to error out (default setting) it will wait longer so you can adjust it while the machine is running.