Messages

3941

General Mach Discussion / Re: CS Labs CSMIO/P-A

« on: August 01, 2018, 06:05:42 PM »

Hi Mick,

Are you using an Allen Bradley motor to match your drive?

Yes, emphatically yes.

Craig

3942

Mach4 General Discussion / Re: G95 mill G99 lathe feed per revolution is it motion controller functn dependant?

« on: August 01, 2018, 03:17:09 PM »

Hi,
my experience is with the mill profile.

On Configure/Control/Spindle page there is a the opportunity to set a Feedback Ratio, ie number of pules per rev.

You could use a single pulse, eg the index pulse of an encoder or you could use one of the quadrature channels if the feedback
ratio is set appropriately. For example set it to 2500 and use one channel of a 2500 line encoder.

Craig

3943

General Mach Discussion / Re: CS Labs CSMIO/P-A

« on: August 01, 2018, 02:59:35 PM »

Hi,
I suspect that the peak power might be 4.8kW but a continuous power of 1/4 or less, about 900W.
A 750W or 1kW AC servo would be a good match.

Craig

3944

General Mach Discussion / Re: CS Labs CSMIO/P-A

« on: August 01, 2018, 02:53:16 PM »

Hi Mick,

Where did you buy the Kinko drives.? Are you using Kinko Motors?

That is exactly what Allan commented about....the desirability that the servo and drive be from the same manufacturer and matched.

There are drives, Granite Drives for one, that are intended to be applied to a range of servos and they do a good job. I doubt they could ever match
a drive and motor from the same manufacturer/ design team.

Craig

3945

Mach4 General Discussion / Re: Lathe Problems with Mach Motion Wizards, Is this Gcode Good?

« on: August 01, 2018, 02:47:11 PM »

Hi,
I suspect DMMs have a very similar set up to the Allen Bradley drive. There will be a programmable register for following error, or whatever DMM
call it.

I suspect also that you can program what the fault signal includes. The Allen Bradley has alarms for over voltage, over current, over heat, following error.
They can be combined into one fault line or over several lines. Such line would be hooked to Mach and then you program Mach how to handle them.
There is also an alarm reset, if memory serves its a distinct input on the Allen Bradley but with many drives it a pulse Mach applies to the fault line
that resets the drive.

Time to look at the manual.

Does DMM have servo setup software that you install as an application on your PC? If it does you might use the software scope to observe your servo while
doing a Gcode job and detect a loss of position. It would give you valuable insight as to how servos work and following errors.

Craig

3946

Mach4 General Discussion / Re: Lathe Problems with Mach Motion Wizards, Is this Gcode Good?

« on: August 01, 2018, 10:53:35 AM »

Hi,
what sort of servos?

Old style brushed servos with DC drives don't have a 'following error window' but detect large deviation between commanded position and
actual position by measuring armature current. If the deviation is large then the servo will attempt to accelerate quickly ( high current) to the
correct position.

AC Step/Direction servos have a commanded input position and compare that to the actual position as indicated by the encoder. Ideally they would be
the same but they aren't. The servo position and therefore the encoder position will always lag a little.

I have an Allen Bradley servo for a spindle motor. It has an 8000 count per rev encoder. I have it programmed with a following error window of 20
counts, ie 0.9 degrees. If it gets more than 0.9 degrees from where it should be then it will fault, signal Mach, and if I wish it, have Mach stop.
I could make the error window smaller but then I would have to use less aggressive moves so that the servo can keep up or it would fault all the time.
Alternately I could make the error window wider and therefore drive the servo harder with a greater difference between commanded position and
actual position but with the wider tolerance or window still not fault.

Understanding how following error is handled is an important part of understanding your machine.

Craig

3947

General Mach Discussion / Re: Gecko G540 64 Bit System

« on: August 01, 2018, 12:12:48 AM »

Hi,
should add the UC100 is very popular, it plugs into a USB on your PC and has a DB25 plug
on the other end which would plug into your G540. A genuine UC100 is about $120US.

Don't get ripped off by EBay or Amazon, there are lots of Chinese UC100 look-a-likes, they don't
work like the real thing. Buy direct from CNCDrive or their nominated distributor....no shortcuts...no
trying to save a dollar...you'll get ripped everytime.

Craig

3948

General Mach Discussion / Re: Gecko G540 64 Bit System

« on: August 01, 2018, 12:08:09 AM »

Hi,
Mach's parallel port driver WILL NOT work with ANY 64 bit Windows OS.

It will work with a 32 bit OS Windows 7 or earlier, XP being common.

If you wish to use a 64 bit OS then you will have to use an external motion controller
like a SmoothStepper or a UC300.

Craig

3949

Mach4 General Discussion / Re: Lathe Problems with Mach Motion Wizards, Is this Gcode Good?

« on: July 31, 2018, 11:22:34 PM »

Hi,
don't know the answer for you but:

I say this, correct me if I'm wrong, but if the servos lose steps I'm assuming the machine would halt or give me an error

Yes I would expect the servo drive to signal a 'following error'. That depends on how, or even if, you have programmed
a 'following error window'. Are your servo drives wired so that if they detect a fault, following error for instance, that
Mach would see it and stop?

Craig

3950

General Mach Discussion / Re: CS Labs CSMIO/P-A

« on: July 31, 2018, 08:48:56 PM »

Hi,
if you are going to continue to use the CSMIO-A as controller then the CSMIO MUST read the encoder
to close the position loop, therefore any servo that has a serial encoder will not work with the CSMIO.

As it turns out there are still plenty of servos with quadrature incremental encoders out there, 2500 line
or 10,000 count is entry level these days. The DMM's I alluded to have a 16 bit incremental and would work
with the CSMIO. Not sure about the Delta 17 bit encoders and even less sure about Delta's 20 bit absolute
encoders. Quite frankly the trend to serial  multi turn encoders is already underway...I think in ten years time you'll
only find incremental encoders on old plant.

As I have already said in this thread; servo drives are becoming increasingly sophisticated and closed loop
capable motion controllers are falling by the wayside.

Craig