Messages

5721

General Mach Discussion / Re: Servo drift due to EM noise. Optical encoders not preventing it.

« on: December 06, 2017, 08:46:11 PM »

Hi,
best solution is to stop the spindle from generating the interference in the first place. What sort of spindle is it?
Where does its electrical supply come from? Is its supply separate from the supplies for the servos/PC/drives etc?

Craig

5722

General Mach Discussion / Re: Servo drift due to EM noise. Optical encoders not preventing it.

« on: December 06, 2017, 08:21:24 PM »

Hi,
Mach is an open loop controller, it issues pulses to your servo drive and that uses the optical encoder to close the loop.
Mach does not read the encoder directly neither does it 'adjust its pulses' to accommodate it.
It sound to me like noise is getting onto the Step and/or Dir lines to your servo drive.

Craig

5723

General Mach Discussion / Re: Mach3 Demo Not running as expected

« on: December 06, 2017, 04:25:09 PM »

Hi,
if you don't have either the parallel port driver or external motion controller installed, ie unable to control motors
then the 500 line limit does not apply. If your installation is capable of running a machine then you need a licence
to get through the 500 line limit.

Mach4 Demo run for about 6 minutes before it needs to be reset and a licence is required beyond that. The exception
is if the Sim(ulator) plugin is used, ie unable to control a machine then the time limit does not apply.

Craig

5724

General Mach Discussion / Re: Need help with my VFD not giving correct speed please

« on: December 06, 2017, 12:23:58 PM »

Hi,
yeah that will certainly do the trick.

Craig

5725

General Mach Discussion / Re: Mach3 issues with new computer

« on: December 06, 2017, 05:27:15 AM »

Hi,
a parallel port breakout board is really only a buffer/amplifier and a place to hook up wires, it doesn't really do anything. Its not impossible
that a poorly designed breakout board could make Mach go screwy but its much more likely that its Machs parallel port driver, that is to say
the software driver running at kernel level on your CPU almost in defiance of Windows that's screwy.

If you want a good board I suggest one from the experienced players and an external motion controller not a parallel port breakout board at all.

https://warp9td.com/
https://www.pmdx.com/
https://www.poscope.com/
https://www.cncdrive.com/
http://www.vitalsystem.com/portal/index.php
http://en.cs-lab.eu/
http://www.galilmc.com/

Don't buy cheap Chinese knock-offs, they abound on EBay, buy direct or from the manufacturers nominated distributor. If you try to buy cheap elsewhere you
will come to grief.

Note that all of these manufacturers have either USB or Ethernet boards or both, and all have Mach4 plugins in addition to Mach3, some more developed than
others, but Mach4 ready none-the-less.

With any of these external motion controllers you will be able to use any Windows OS including 64 bit so the choice of PCs to run Mach just became huge
and even more importantly they run Mach a lot smoother and way way WAY less faults than a parallel port.

A lot of Mach users depend on a parallel port and vigourously defend its use, I used to do the same until I bought an Ethernet Smooth Stepper, now I wouldn't
go back to a parallel port if you paid me!

Craig

5726

General Mach Discussion / Re: Need help with my VFD not giving correct speed please

« on: December 06, 2017, 04:19:47 AM »

Hi,
yes I trust Delta, a lot cheaper than equivalent US/European brands but not absolute bargain basement prices either. If you go real cheap you might reasonably
expect trouble.

Delta have a couple of VFD model lines, from memory VFD-B and VFD-D. The VFD-B series has a digital frequency output that the slightly less capable series doesn't and
as I discovered when helping another guy on the forum it is very useful.

Delta also do a couple of very respectable lines of servos and drives.

Before getting too carried away and buying something new and trying to hide the fact from your wife why not use the current input?. Pretty simple circuit required
to convert to current drive. Second issue is 'do you actually require precise and agile speed control?'. I've found that most jobs I do require that I set the speed
once at the start of the job and it stays that way until the job is done hours later. All that is required is turn it on and off. Sure a hell don't need to go backwards!
I have, like many, spent a lot of time, energy and money trying to achieve the best speed control only to realise that 95% of that capacity is wasted. In my case
I wish I'd spent the extra on high pressure coolant pumps and filters rather than spindle control. It is quite possible that your existing VFD could still be used to
good advantage and you could hang onto your dollars to get something really useful, perhaps with enough left over for a bunch of flowers for your wife too...LOL.

Craig

5727

General Mach Discussion / Re: Need help with my VFD not giving correct speed please

« on: December 06, 2017, 12:40:01 AM »

Hi,
well that is some useful information.

The CV terminal input impedance:
Z=V/I  =(10-.5)/(.5/1000)= 19kOhm

The CI terminal input impedance:
Z=V/I =(10-8.5)/(8.5/1000)=176Ohm

Those numbers seem reasonable. Note that the current going into the CI terminal is 8.5mA and that was sufficient to drive it to 24000 rpm. It really
rather suggests that the voltage input terminal is faulty. Is it possible that its taken a hit?

How about connecting your 10V direct to the voltage terminal to see whether it will drive the spindle to full speed.

Shame about the documentation. I have a Delta VFD (Taiwanese) and am very happy with it and the documentation is good, as good as any US/European VFD
documentation. Must say have never been tempted to buy any Chinese brand cheaper than Delta.

Craig

5728

General Mach Discussion / Re: Teknic Clearpath Servo setting for Mach3

« on: December 05, 2017, 06:44:20 PM »

Hi,
have you tried Chaoticone's suggestion of 1200 steps per mm?.

When you perform a move to establish whether you have the correct setting try to move it as far as you can accurately measure.
Any measurement errors decrease, as a percentage, the bigger the move.

Also what following error window have you programmed into the drive?

My Allen Bradley servo I programmed the following error limit to be 20 count (8000 count per rev) and the zero window
as 4 counts. If your window/windows are too wide the drive may believe that the servo is in the correct location and not
bother to try and close the error any more.

Craig

5729

General Mach Discussion / Re: Teknic Clearpath Servo setting for Mach3

« on: December 05, 2017, 05:46:22 PM »

Hi,
when you say 'its not working' what do you mean? Does the servo turn at all? Need to get it to turn THEN
worry about steps/mm.

Craig

5730

General Mach Discussion / Re: Need help with my VFD not giving correct speed please

« on: December 05, 2017, 03:45:43 PM »

Hi,
are they separate input pins?

It seems that the device is happier at current input than otherwise.

Still tempted to recommend feeding the input via 1k resistor and measure the voltage drop, its the classic technique
for measuring input impedance.

Craig