Hey everyone, first time poster....long time listener.
I bought a Hyundai Hit8s with a Siemens 840c control and it is an electrical nightmare. I searched and could not find any successful conversions, I was hoping someone in here had some experience with the 611 analog Simodrives. I am currently on a wild goose chase for the manuals which seem to be extinct.
I know the spindle can be controlled via 0-10v but the X and Y have "tachometers" in them which seem to be proprietary to Siemens. I don't mind using new drives and servos but I would really like to re use what I can. The drives themselves are fine but the PLC CPU seems to be falling apart and not allowing for long NC operation.
Any reading material for a guy who bought a fantastic lathe but horrible controller?
OAK compatibility with Siemens 611a (analog) AC servo drives
Moderator: cnckeith
Re: OAK compatibility with Siemens 611a (analog) AC servo drives
Assuming those are the "Simodrive 611" system that was found on some Bridgeport VMC machines; and assuming that all such drives have the same interface features; then they should be controllable with the Oak.
The only significant issue is that the Siemens drives require a +24V signal (positive logic) to enable, while the Oak will only provide a pull-down-to-0V (negative logic) enable signal. This requires that you insert a relay between the Oak and the drive, so that Oak can activate the relay (enable signal to minus side of coil); and the relay can switch +24V to the drive's enable input.
You also need a quadrature differential encoder signal to the Oak, for axis position feedback. In my very limited experience with Siemens drive systems, it is typical to have a separate encoder for that purpose (separate from the tachometer or encoder that provides feedback to the drive). Bridgeport VMCs, for example, have two encoders on each motor: one wired to the drive and another wired to the CNC control.
For an example of a retrofit with Simodrive 611, see:
https://centroidcncforum.com/viewtopic. ... 97&p=53792
The only significant issue is that the Siemens drives require a +24V signal (positive logic) to enable, while the Oak will only provide a pull-down-to-0V (negative logic) enable signal. This requires that you insert a relay between the Oak and the drive, so that Oak can activate the relay (enable signal to minus side of coil); and the relay can switch +24V to the drive's enable input.
You also need a quadrature differential encoder signal to the Oak, for axis position feedback. In my very limited experience with Siemens drive systems, it is typical to have a separate encoder for that purpose (separate from the tachometer or encoder that provides feedback to the drive). Bridgeport VMCs, for example, have two encoders on each motor: one wired to the drive and another wired to the CNC control.
For an example of a retrofit with Simodrive 611, see:
https://centroidcncforum.com/viewtopic. ... 97&p=53792
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Re: OAK compatibility with Siemens 611a (analog) AC servo drives
Excellent, that link seems to have very similar drives to mine which is excellent news. Those issues you listed also seem to be easily solved, I think i am ready to take the plunge if and more likely when the machine kills another PLC CPU.cncsnw wrote: ↑Mon Dec 18, 2023 1:59 pm Assuming those are the "Simodrive 611" system that was found on some Bridgeport VMC machines; and assuming that all such drives have the same interface features; then they should be controllable with the Oak.
The only significant issue is that the Siemens drives require a +24V signal (positive logic) to enable, while the Oak will only provide a pull-down-to-0V (negative logic) enable signal. This requires that you insert a relay between the Oak and the drive, so that Oak can activate the relay (enable signal to minus side of coil); and the relay can switch +24V to the drive's enable input.
You also need a quadrature differential encoder signal to the Oak, for axis position feedback. In my very limited experience with Siemens drive systems, it is typical to have a separate encoder for that purpose (separate from the tachometer or encoder that provides feedback to the drive). Bridgeport VMCs, for example, have two encoders on each motor: one wired to the drive and another wired to the CNC control.
For an example of a retrofit with Simodrive 611, see:
https://centroidcncforum.com/viewtopic. ... 97&p=53792
You are correct that all of the axis have a separate encoder aside from the internal positioning encoders. I have a plan B/worst case plan to use the spindle Simodrive since it would be 0-10v control and replace the X and Z with more suitable servos and drives for the Oak. <y goal is a quick install as I am production shop and in need of this lathe to work badly.