My boss tasked me with retrofitting an older sharnoa sdc20.
Ive built stepper based cnc machines. Never anything with servos.
He is a guy who wants to spendnothing and get everything. Im tasked with doing this as cheap as possible.
The sharnoa used Fanuc 6m motors . The drives and motors still work so I was hoping to hook up a motion controller or break out board and call it a day.
Can any one verify a smooth stepper board will hook up to these drives (link bellow) there the exact same ones used by the sdc20.
Any pointers?
Mark
http://www.ebay.com/itm/FANUC-DC-SERVO-DRIVE-VELOCITY-CONTROL-UNIT-A06B-6047-H003/132013649005

Hi mrich0908,
don't know anything about Fanuc except that they're frighteningly expensive and the byword in quality.

When you say that the servos/drives work, how do you know? What did you use to test them?

Given their apparent age I'm guessing that they might be analogue input type drives in which case a SmoothStepper
(being pulse step/dir) wont work. I know Hood uses CSlabs gear and they do an analogue version/addons as do other
manufacturers but they are all much more expensive than a SmoothStepper.

Do some research and find out what the drives require as input for position control.

Craig

Im able to jog them with the old tiger 4 controller as is  . Whats the difference between analogue  drivers vs  digital .
The picture I have of the driver matches another picture Ive found stating its a AC not DC digital servo driver.
So what does this change for me ?
http://www.cnc-shopping.co.uk/a06b-6057-h007-ge-fanuc-digital-servo-drive-p-1950.html?osCsid=5d6c6608836b646384c895410bbf31b8

Hi mrich0908,
that sounds pretty hopeful.

The 'digital' part refers to the input of the  driver. In M3/SS terms that means two digital signals, one controlling direction and the other to step in the
given direction. Older style drivers had one analogue input, a varying voltage between -10 to +10V and the servo would drive to match that, say extreme
left at -10V and extreme right at 10V.

The AC part of the description refers to the fact that the driver synthesises three AC voltages to Apply to the windings of the motor to make it move
and the encoder tells it if its done enuf or whether it needs to make more AC to match your position instruction.

What you have described sounds like it could be controlled by a SmoothStepper. Would need to see some document which proves it, ie 'with jumper X in
position Y the input control method is step/direction...' or least something that would prove it to your boss.

Craig

What do you mean by "jumper X in" Im illiterate when it comes to servos.
Any suggestion on drives . I want to say I seen something saying they operate at 185v and 9 amps. I dont mind them being slightly under powered . No one here is looking for blazing fast rapids. We have a few new Hass machines for that.

Hi,
the documentation of the drives you've got should tell you how to configure it so that it can accept step/direction inputs.
You need that documentation.

Craig

The machine is from 1990 it has 0 documents.
I can buy new drivers . Im just looking for leg to stand on.

Hi,
new drivers are expensive, I thought you were trying to minimise cost by retaining the existing motors and drives.

If so search until you find the documentation that describes what you've got. I'm not sure but I believe Fanuc have an 'input'
board that attaches the drive proper and that board is what determines the required input signals.

One possibility to be aware of is that some of these drives are not meant to be used as position control, they're intended as
speed controlled devices ie spindles.

If you have to replace/repair the drives/motors you may be advised to ditch Fanuc, good but really pricey. Have a look on Ebay
or Ali express, Delta servos and drives are readily available around the $600-700 for 1hp with 10000ppr incremental encoders
and around $1000 for absolute encoders, that's the motor AND drive, good value and they have a steady reputation. They're a bit
like an 'asshole'...'everyones got one!'. There are cheaper makes on Ali Express as well but for me at least unknown reputation.

I of course don't know your boss, I don't know what makes my boss tick either... but I know what makes him explode!

Craig