I just found out my servo drivers are analog +10/-10 v What are my options?

[martyscncgarage]

I'm going through looking at the options you guys have posted slowly.

Has anyone dealt with viperservo.com out of Canada before? They make a servo drive that would work as well as a $90 step/direction to analog converter that would allow me to use my current configuration supposedly. http://032c30a.netsolhost.com/catalog/p ... ucts_id/56

Over complicating the build. That machine is small enough for hybrid stepper drives or even better, Clearpath SDSK drive/motors. DC brush servo is old technology and you have to tune them.
I would ditch the DC brush servos on the axis and see what can be done to keep the spindle motor for awhile.
I'll look at that manual tomorrow.

Marty

[Muzzer]

Those motors are BrushLESS, not brushed, so a DC brushed drive wouldn't be much use. These are often referred to as BLDC drives and use a "6 step" or "trapezoidal" control scheme. They appear to be mostly analog, rather than modern microprocessor based. I'd junk them along with the motors and fit a modern closed loop system, either closed loop stepper or servo. You won't find many drivers that will work with those motors.

Interesting they even include quite a few schematic circuit diagrams, showing a whole forest of opamps and discrete devices. I wouldn't invest any more time and money around those. These drives appear to be about 20 years old. When was the machine originally made?

[Richards]

Sometimes the easiest solution is to sell the things that don't work and then buy something that does. The DMM DYN2 and DYN4 servos/drives are popular as are the Teknic ClearPath servos. I still have a Gecko 320 servo driver, a DC servo motor and a 70 VDC power supply that I bought about 20 years ago. I could probably use it, but its just not worth the time and frustration to fiddle with. Tuning that motor is almost impossible, so I cut my losses and moved on. The Pronet drives and servos offered by Centroidcnc look very good. If budget is holding you back, closed-loop steppers are not much more expensive than open-loop steppers. I've never used them but Marty, Gary, and Franco have all posted very favorable posts about closed-loop steppers.

There was a saying on the farm where I grew up: "You don't put a $1,500 saddle on a $10 horse." Sometimes fiddling around to make something work becomes that $1,500 saddle, even if it is inadvertent.

[martyscncgarage]

Yep, brushless...end of day and my haste.
Did you keep the signal cable that connects to the spindle drive? What pins is it connected to. It can give some clues.

I would definitely not bother keeping the Glentek drives and motors. Move on to newer technologies which Acorn can directly control.
Stepper, closed loop stepper, Teknic Clearpath SDSK, DMM AC servos.

I wouldn't toss the spindle motor and drive just yet. But I would have done some detective work before dismantling the control. As I mentioned, if you have the spindle drive signal cable plug it back on to the drive and determine what pins are used.

Marty

[Setlab]

These DM2800 mills were made in the 90's, so yes everything is about 20 years old. I did find one inspection sticker on one of the electrical components dated 1997 so I'm pretty sure that was the manufacturing year as I think the company shut down shortly after that if remember right.

I think I was just caught up on the fact that servo motors sound more professional and I could learn something potentially important for the future. You guys convinced me to look around at different options though and I was really surprised how cheap the closed-loop stepper kits are from stepperonline. For the cost of a motor and driver, I'm well within my don't stress about it price range. I'm putting off impulse buying all 3 axis motors and drivers until I can take time to ask around or figure out what the proper stepper torque equivalent would be to my current servo motors in a NEMA 23 or 24 frame. I also re-watched Mr. Pete's video on his servo spindle drive replacement and his decisions seems pretty sound, I think I might buy a similar spindle motor setup as they're pretty affordable to me as well. Marty, your youtube page and Pete's have been a big help so far in learning or motivating me to buy expensive stuff in the case of Mr. Pete lol.

I really would like to buy all clear path servos, but I don't think I'm ready to spend that amount of money all at once. Especially since I just started to consider a much cheaper closed path stepper conversion.

[martyscncgarage]

Hold off on buying the AC servo for a spindle motor....because as far as I know, I really have not seen a successful, stress free, reliably working implementation of an AC servo as a spindle motor.

Do you have the cable that connected to the inputs of the spindle drive? Please take a picture so we can see which pins are used......let's see if it's worth saving.
The motor and drive are already tuned together.

Marty

[Setlab]

Here are the motor and cable connections for the spindle motor. What kinda information can you tell by the connectors?

Just realized these are not what you were asking for, I'll hook the ends to the old drive in a sec and take some pictures of the connected wires.

[martyscncgarage]

Here are the motor and cable connections for the spindle motor. What kinda information can you tell by the connectors?

dm2800 spindle motor conectors.jpgdm2800 spindle motor cable conectors.jpg

Just realized these are not what you were asking for, I'll hook the ends to the old drive in a sec and take some pictures of the connected wires.

Not that connector, the connector that went from the old control to the Glentek DRIVE. (J1 I believe) and save that harness.
Marty

[Setlab]

Here is everything in one picture

Here in the J1 connector

Here is the other J4 conector

Here is where all the other wires terminate in on the mainboard

[martyscncgarage]

In this photo, I assume the cable goes up to the spindle motor?

And trace this U axis cable. Might it go to a spindle encoder?

This is good detective work.