What motor to use for lathe spindle?

[TRM]

Hi guys

The spindle motor on the machine is a CTB brand china 2.2KW 3hp servo and has a driver in the cabinet.
I don't want to entertain the idea of trying to make it work with Acron. I want something I can get support for and/or do myself.
So this was the first part I pulled and plan on getting squared away first.

I have 2 options.
1: Is regular C face mount 3 phase motor and VFD. Lesson makes a 3,4 and 5.5 hp metric motors with a 28mm shaft that the pulley will fit.
The lathe motor mount plate will need to be modified for the Lesson motors to bolt up. No big deal.
Draw backs to this option. The CTB servo motor weighs 60lbs. Lessons range from 93-115lbs. And the lesson motors are to long to fit in the lathe without modified the coolant funnel and moving a brace under the stand.
Cost: 5.5hp motor $626.00 VFD $283.99 braking resistor $50.00 Centroid encoder cable $85.00 encoder $240.00. total cost $1284.99

Plus at least a day modding the stand to make room for the longer motor. Only need about an inch... lol And that's if the extra 40 plus lbs don't cause issues with belt tracking due to bracket flex. It's 3/4 mild steel BTW.

2: Is use a Clearpath Integrated Servo motor. Step and Direction. Can Acorn use this motor as a spindle motor and thread?
If run on 3 phase power they rate it at 4hp continuous and 7hp peak. If run on 220V single phase the power is a little less.
Draw backs to this option. RPM is limited to 2760. I don't think that is a big deal. I make parts on my manual lathe with a 2000 rpm limit and get by just fine. Weight 28.3 lbs. It's about 2" shorter than the CTB motor I took out so it would fit with no issues. The D100* frame size also has a 28mm shaft
so my pulley with work but like the Lesson motor the motor mount plate will need to be modified for the motor to bolt up.
Cost: Motor with cooling fan $1232.00 CPM-CABLE-M2P2P-120 $13.00 CPM-CABLE-CTRL-MU120 $23.00 RES-225 Regenerated Energy Shunt $152.00
Total cost $1420.00
https://www.teknic.com/model-info/CPM-S ... =230VAC3ph


The lathe is setup with Nema 42 AC servos. My plan is to replace them with DMM servos of the same size.

[Dave_C]

Is use a Clearpath Integrated Servo motor. Step and Direction. Can Acorn use this motor as a spindle motor and thread?

TRM,

Acorn can not use step and direction for spindle control!

Acorn outputs 0-10vdc control for motor speed and uses relays to initiate start and stop of a VFD for spindle control.

Dave C.

[travasky]

Can you post a picture and/or model number of the CTB servo drive? Ill bet it takes analog voltage( almost all spindle servo drives do) and would be simple to set up , especially because its already been tuned to the motor. Total cost: $0.

You might be surprised how helpful some companies overseas are. If the motor is being used in conjunction with a Siemens control that might be an indicator that the machine integrators have had good luck with them in the past.

[TRM]

I'll be delighted to mail it to you with the motor and let you sort in out send it back ready to plug and play and pay you for your time.
I will send you one of the axes motor and drive as well. Provided the cost is considerably less than new parts.
Clear path has 2 other models in the same frame size that may take 0-10V input. I need to call and check with them.

CTB Spindle Drive

Siemens Axes motor drive

Siemens V60 Axes motor drive manual.
https://cache.industry.siemens.com/dl/f ... _en-US.pdf

[Dave_C]

Ill bet it takes analog voltage( almost all spindle servo drives do)

Interesting! I read through the manual posted above, I looked at all the input terminals and I didn't see anything that would accept 0-10 vdc control for speed on this drive.

It has a TTL encoder with an Index pulse so the encoder is not going to work with the Acorn board just in case that was the intent.

I'm not familiar with the control that ran the lathe so I'm puzzled as to how they got this to run a spindle on step and direction?

What am I missing here? Would this control have output a series of steps at a certain frequency to make the servo run at the commanded speed?

Dave C.

[TRM]

Sorry I didn't make it clearer.
The first pic is the China CTB spindle motor drive.
The second pic is the Siemens axes motor drive.

[travasky]

I just looked up the spec. It has 0-10V input or -10-10v input. Youre good to go on the 0-10v input. It also has a RS422 line driver output for the encoder to pass that signal along to the control. Does this machine also have a separate spindle encoder?

Heres the manual for the driver. http://www.ctbservo.com/UpLoadFiles/Oth ... 031822.pdf

There not really any configuration to do other than give it the 0-10v signal, hook up fault wiring, etc from the acorn and configure the acorn software properly by following the setup guide. If I had it in my hands there's nothing I could really do with it. Im assuming you have looked at the standard acorn wiring diagrams?

[Dave_C]

Sorry I didn't make it clearer.
The first pic is the China CTB spindle motor drive.
The second pic is the Siemens axes motor drive.

Ok, that makes sense now! I agree with what travasky said above. If it were me, I'd use it and hook up the RS422 output to acorn for threading.

It should work...

Dave C.

[TRM]

The Lathe has a separate encoder belted to the spindle but it has no wires hooked to it.
The encoder being used is in the motor. The encoder cable from the motor hooks up to the drive and another RS cable comes from the drive and connects to the 808D encoder port.

I have seen higher hp lathes use a VFD and regular 3 phase motor and the separate encoder.
It's my guess that all the machines left one part of the plant ready for any motor type.

[TRM]

Sorry I didn't make it clearer.
The first pic is the China CTB spindle motor drive.
The second pic is the Siemens axes motor drive.

Ok, that makes sense now! I agree with what travasky said above. If it were me, I'd use it and hook up the RS422 output to acorn for threading.

It should work...

Dave C.

I would love to do that but I don't understand this on the level that you guys do.
I got a smoking deal on the machine and I can afford to retrofit it. I planed on the worst before I bought the machine.
If I buy DMM servos for the axes replace the spindle motor at least I can get a little support to help fine tune things.
Centroid offers support by the hour and I plan on buying support with the purchase of the acorn board.

If one of you guys want to show me where to hook wires 123 to ABC and post the pic's I will pay you for your time.
This is a part I made a few weeks ago on a friends Mazak. This was a 1000 part run. the last time I got the order it was 1500 parts.
I do things like this frequently.