[strantor]

I am trying to break out of a strong mental mire; a combination of analysis paralysis and brain fog. I need your help to make a decision, and I'm hoping that maybe just spelling it out here will bring things into focus.

Relevant history:

• My mill is circa 80s, originally shipped with DC servos and a Dynapath control system.
• Previous owner replaced the DC servos and amps with AC servos (whatever he had laying around) and AB Ultra 100 servo drives. He used the Ultra 100 drives because they take analog inputs like the previous DC amps.
  
  • X: enormous Fanuc 8F/2000 (12Nm/106 in-lb, 2000RPM)
  • Y: AD SureServo SVL-210 (9.8nm/87 in-lb, 4500RPM)
  • Z: AD SureServo SVL-210 (9.8nm/87 in-lb, 4500RPM)
  • I really like the SureServo motors on Y & Z because they're small and I know they work.
  
  
• I retrofitted the Dynapath controls to Linux CNC. I used Mesa 5i25/7i77 because it takes encoder inputs and outputs analog to the drives, which is how they were already set up, and I didn't want to mess with them.
• CNC worked great for a few years.
• Z-Drive died. I kept using it for manual operations, using the knee to control Z height.
• Y-drive died last week. Now I can only use it for milling slots.
• X-drive is the only axis that still works, and it's the axis that has that massive fanuc motor that I hate because it's so big it hits the Y-axis ways so I have to limit the x-travel.

Here's what I have on hand as potential solutions (these are all 1kw options):

• 1X AB Ultra3000i servo drive circa 2004 (tested, working)
• 1X matched set AB N-series servo (7Nm/62in-lb, 5000RPM) and 1398-ddm-009 ultra series AB servo drive out of a machine that hasn't run in many years (untested, unsure whether capacitor re-forming and testing is worth the time)
• 4X matched set DMM DYN4 servo drives with 11A-DST-A6HK1 servo motors (12Nm/106in-lb, 3000RPM). These are relatively new, very low hours and light use, and were used on a non-CNC prototype machine where they were supposed to run from analog input signal. Their performance with analog input was very erratic and that's why they were removed. I think they are only good for pulse/dir operation, if anything. I have been saving them with the intent to make a fully DIY 4 axis machine. They have inconvenient modifications to the power and encoder connectors.
• 1X matched set LS L7C servo drive and APMC-FCL10AYK-AD servo (9.5Nm/84in-lbs,5000RPM). This was purchased for evaluation in a non-CNC application and found that a larger motor was needed. Brand new, works great with analog input, smallest form factor motor of any option, I think this is getting used no matter what.

So now that I've spelled it out, I think this might be the way forward:

1. Take the Fanuc motor off X, replace it with the LS motor and drive.
2. Remove the bad Ultra100 drive from Y, and Use the good Ultra100 drive from X to run Y, with existing SureServo motor.
3. Remove the bad Ultra100 drive from Z, and replace it with the Ultra3000i drive.

Are there any more reasonable options that I'm missing? I want this to be as non-invasive as possible but I also want that chungus fanuc motor out of the picture.

[strantor]

Here are some pictures:

Motor options, top to bottom : LS, DMM, Allen Bradley, Existing Fanuc
https://drive.google.com/file/d/1-JM...ew?usp=sharing
https://drive.google.com/file/d/1-7P...ew?usp=sharing

Current maximum X-travel due to Fanuc motor:
https://drive.google.com/file/d/1-8w...ew?usp=sharing
https://drive.google.com/file/d/1-Ax...ew?usp=sharing

Misc relevant pics:
https://drive.google.com/drive/folde...usp=drive_link

[joeavaerage]

Hi,
where do you get your numbers?


A11A-DST-A6HK1 servo is 4.4Nm (S1 rated) and 1500 rpm (rated) Sure the max is 12Nm and 3000rpm, but neither of those max numbers is accurately describing those servos.
It would produce 12Nm for probably ten seconds before faulting over current.

Rated, or continuous, often called S1 is more realistic and descriptive rather than extreme max.

I see you've done the same thing with the Sure Servos.
An SVL210 is abut 3.5Nm S1 up to 3000 rpm and then tapers off up to 4500.

Craig

[strantor]

Hi,where do you get your numbers?A11A-DST-A6HK1 servo is 4.4Nm (S1 rated) and 1500 rpm (rated) Sure the max is 12Nm and 3000rpm, but neither of those max numbers is accurately describing those servos.It would produce 12Nm for probably ten seconds before faulting over current.Rated, or continuous, often called S1 is more realistic and descriptive rather than extreme max.I see you've done the same thing with the Sure Servos.An SVL210 is abut 3.5Nm S1 up to 3000 rpm and then tapers off up to 4500.Craig

I get the numbers from the datasheets and yeah I was using the Max numbers, not continuous duty*, not sure why. *for everything I could find datasheets for, which means everything except the Fanuc.

[joeavaerage]

Hi,
If I'm not mistaken Sure Servo is a Delta servo (Taiwanese brand made in China) rebranded for the US market.

Sure Servo2 is the equivalent of a Delta B2. Your existing Sure Servos are of an earlier type , Delta AB I think. The Delta AB has a 10,00 count/rev encoder. Unless the Allen Bradley drive has a 10,000count/rev
encoder input, then I do not think you can mix the Sure Servo and the Allen Bradley drive. I have an Allen Bradley 3000i drive and it has an 8000 count/rev encoder so definitely would not match any Sure Servo motor.

I use 750W Delta B2 servos (five of them) (2.4Nm S1, 7.1Nm max, 3000rpm rated, 5000rpm max), and they have a 160,000 count/rev encoder. They MUST have a matched drive. Trying to mix and match drives
is a a very error prone choice. These are, I believe, called Sure Servo2 in the US.

The best servos/drives you have are the DMM's. They will work from analogue input but are best as Step/Direction. You do not need LinuxCNC to close the position loop, leave that to the Step/Direction mode of the drive.

Craig

[strantor]

I screwed around all weekend and all of monday with all these old drives and motors and I'm ready to set fire to the whole pile. I am making a knee-jerk course change, replacing all the servos and drives with brand new. Looking at LS servos and drives from AutomationDirect. I made a new thread about this.

[Al_The_Man]

I see those drives can be used in voltage or current mode, current/torque mode is considered the better choice.
The systems I put together, the encoder is returned to the controller only and the drives are torque mode capable in this way I can mix and match motors and drives easily.
.

[strantor]

I see those drives can be used in voltage or current mode, current/torque mode is considered the better choice.
The systems I put together, the encoder is returned to the controller only and the drives are torque mode capable in this way I can mix and match motors and drives easily.
.

Ok thanks, I never considered that. I will give it a shot when I get the new servos in.