Cincinnati Milacron Arrow 750 Retrofit

Hello Everybody,

I recently purchased a Cincinnati Milacron Arrow 750 from a local shop. The machine is equipped with Siemens Acramatic 2100 and was giving the original owner intermittent issues with both the controller and drives. The physical machine is still in good condition so I purchased it with the intention of retrofitting with Mesa hardware and Linuxcnc. I plan on running this machine in my garage so I'll be converting to single phase as well.

I'm currently in the process of stripping down the enclosure to gain access to switches, sensors, motors, etc... and to reduce the size for passage through my garage door opening.

I removed the z-axis motor and noticed that it's a Siemens 1FT6064-6AF71-4AB1. I looked up the specs for this motor and it has a 2048 1Vpp Incremental Optical Analog encoder.

Right now I'm considering going with the 5i25, 7i77, 8i20, and additional IO cards as necessary.

I'd like to keep and use the original 1Vpp encoder on each servo motor. What is the best way to interface the analog signal of these encoders to drive the 8i20 commutation? Do I need to convert the analog signals to absolute digital or is there a Mesa interface card that can directly process these analog signals?

the 7i77 will read this signals fine SIEMENS runs as TTL
just check them by 5V and oszilograph if the index is ok
as you say this Motors like to break on index as on Hard stops

Does that mean the 7i77 will read the sin/cos signal from the Siemens encoder as TTL? Can that signal be used for motor commutation?

Thanks for the suggestion.

I've searched through the forum a little bit and found that HAL needs the rotor angle to know which field winding to energize when starting to rotate after initial power up. Since the sincos encoders on these Siemens servers can provide initial rotor angle in analog, I would need to convert the analog signal to digital and feed that angle into HAL somehow.

Mesa sells the 7i80DB that (I believe) allows me to communicate to HAL via a SSI or BISS communication protocol. If I build (or buy) an interface that converts the analog signal to digital, can I use the 7i80DB to get a digital absolute signal to HAL to start rotating the servo?

Yes, I agree the STMBL driver would be the perfect fit but certain IC's are no longer available as you mentioned, and haven't been for a little while now.

Do you know if a redesign would be available in the next month or two? If not, I think the 8i20 and some 1Vpp sin/cos interface would be my next best option aside from Granite drivers which are a bit too pricey...

Does anybody know if the SPI interface on Mesa boards are fast enough to process rotor angle commutation? I found some TI online documentation that describes exactly what I'm trying to accomplish.

www.ti.com/lit/ug/tidua05a/tidua05a.pdf

I'm just curious if anybody has tried something like this and had success or insurmountable issues.