[daviruz]

I recently bought a vertical cnc mill controlled by sinumerik 810M GA3.
The battery had gone dead, and the machine had been disconnected for a long time, so the memory was dead. The PLC program was included in paper print format, so i was luckily able to restore that, but all the machine data was missing, so i've been playing around with it and gotten almost everything to work perfectly. Except for the spindle.
The spindle is powered by a servo motor with a 1024cpr encoder, hooked up to a servo amp much like the ones that control the axis servos. The servo amp takes a +/- 10V input which corresponds to 6000rpm rotation in either direction.

The problem is, it doesn't matter which velocity i enter in the sinumerik, it always sends out 7.5V, which gives 4400rpm.
The machine data which controls this is 4030, which specifies how many rpm's are produced at 10V output (6000).
I have tried assigning the spindle measuring circuit to a axis instead, and when i do this i can run it at any velocity just fine, so the servo amp and analog output seems to work just fine. I'm pretty sure it's a configuration issue.
On the spindle diagnosis screen it's possible to see the velocity command the sinumerik is supposed to use, it's -8192 to 8192 for -10 to 10V. If i enter 50rpm, the value is ~68, which should be correct, and correspond to 82mV, but for some reason it still sends out 7.5V

Sorry for the kind of long post, but i wanted to include as much details as possible.
I've been through the sinumerik documentation many times, but the answer still eludes me.

[gridley51]

It is a parameter problem but I can`t remember which.It`s not the one that looks obvious.
I`ve had this on a Chiron which also uses an axis drive on the 610 to drive the spindle.
You could also adjust the tacho pot on the drive but it`s not the correct way.
What machine,motor and drive?

EDIT: Silly question,you don`t have the spindle overide switch turned down,do you?

[daviruz]

The machine is a Busch CNC-NF1, chances are no one has heard of it.. :-)
The motor is a siemens 3.4kW AC servo, 1FT5072-0AK71-1.
The drive is a simodrive 611, 6SN1118-0AA11-0AA1 i believe.
The position of the spindle override doesn't matter, it's 7.5V and 4400rpm regardless of what i set it to. Even if i adjusted the pot at the drive i would still only get one single speed on the spindle.

[gridley51]

If the position of the overide switch makes no difference then the parameters are set wrong.Have you downloaded the pdf`s from Siemens?

[daviruz]

Yes, i have been through each and every one of the machine data parameters in the installation guide (pdf from siemens) affecting the spindle several times.
The override switch does update the value on the screen (if i set the switch to 50% it also shows 50% spindle override on the screen), and it does TRY to change the spindle speed (made evident by the "set speed" VELO value in the spindle monitor under diagnosis), but it still outputs the dreaded 7.5 volts.

[gridley51]

Daviruz.There is more than one setting in the MD for controlling the speed.I know what you are saying about 4030 but there are other ones.
The milling m/c I have with a 1FT5 servo motor spindle is controlled with an 810M but a GA1
I think I have an 810 GA3 on a lathe but I do not have a copy of the data but my son has and I can get it tomorrow.It`s really only the spindle data you need and what I have should be good enough to compare but the machine has a Mentor drive and 60Kw motor but I don`t think that will matter.

[daviruz]

Some reference machine data to look at would be great. I'm not sure what's different in GA1, but the GA3 data should be valuable as long as it has analog spindle control.

[gridley51]

Daviruz,send me your email address and I will send you machine data for a lathe with 810T GA3 control.
Mark.

[F.Sharifi]

dear sir
1- check the machine uses the gear box or not
2- this matter of wrong gear change value , control always caculate the out pot to spindle dirve based on rpm that you choose , the send the value to 56-14 on drive
3- if always send 7.5 volt , that means you dont have gear change value in machine data
4- be sure if you dont have any gear box in machine actual control must be knows that , it means you must mention same value for each gear renge then control knows that is no gear box
5- send me the copy of machine parameter i check and chang it for you , but let me know there is gear box with what step renge or ,..and min and max spindle rpm

thanks
regrads
F.Sharifi

[daviruz]

Issue resolved!
Thanks everyone for offering to help, i'm sorry i couldn't be more helpful myself by posting the machine data. Chances are someone would have spotted the silly mistake a lot sooner than i did. Never the less, i thought i'd post my findings in case someone runs in to similar problems.
I have been running the machine with an external adjustable voltage source, not a very pretty solution but it worked sort of well enough.

NC MD 4030 was supposed to be set to 6000 (6000rpm at 10 volts), which it also was. But i had accidentally also set NC MD 4010 to 6000. This setting is an offset value entered in VELO units, and 6000 gives 10*6000/8192 which is approximately 7.3 volts. After setting it to zero, everything works perfectly.

[erdinct]

your servo systems are 611 A ?. If have 611 A or 610 spindle drive you can adjust control parameter P14....