Messages

6141

General Mach Discussion / Re: input signal hotkey & Win 64

« on: October 27, 2017, 04:47:06 PM »

Hi,
I have Mach3 on my laptop, Windows 8 64 bit and I can assign a hotkey just fine.

In the pics attached I assigned Input#1 as enabled, emulated and emulated with lower case a. After restarting Mach on the diagnostics screen Input#1 LED operates
on <a> as expected.

I note from the link you posted that it would fail with a real time signal like Probe, haven't tried it yet.

Craig

6142

General Mach Discussion / Re: Torch relay turns on and stays on when I start mach3.

« on: October 27, 2017, 04:25:01 PM »

Hi,
try this as an experiment. Turn on Mach. Is the relay on?

Go to the MDI screen an issue M03. Does the relay change state? Now issue an M05, does the relay change state?

Craig

6143

PoKeys / Re: Change Stepper to Servo

« on: October 27, 2017, 11:48:20 AM »

Hi,
get some proper information about those servos. They sound too good to be true.....and therefore probably aren't true.

130 for proper servos....yeah right! Good luck.

Craig

6144

Mach4 General Discussion / Re: How to use G28.1 on Mach4?

« on: October 27, 2017, 10:45:38 AM »

Hi,
when you say check it do you mean drive to 0,0,0 and visually check it or manually measure it?

If your steppers are losing steps or you think they might you should fix that....and closed loop steppers aren't the answer, properly specified steppers
and drives are. My steppers have not lost a step except when I do something stupid or crash them for three years. I can operate my mill all day without
re-referencing or if I do find its less than 5um from when I referenced in the morning.

If you can achieve that sort of reliability then G28.1 or some other ref-all-home mid session just becomes a waste of time.

Craig

6145

PoKeys / Re: Change Stepper to Servo

« on: October 27, 2017, 10:31:39 AM »

Hi,
there are lots to chose from, Leadshine 86HS85 are 8.5Nm units  for about $80, even bigger 86HS120 which are 12Nm are about $200.

Note these with the AM882 are open loop systems. Closed loop systems tend to cost more yet not really get any advantage, they are still stepper
motors, a closed loop driver done not make them any more powerful or faster. They will try to make up for lost steps if there are any but in most cases
if they lose steps they can't make them up because they're just plain overloaded so the drive faults 'following error' and shuts Mach down.

An 8.5Nm motor and drive would cost about $155 plus shipping. A 400W Delta servo is rated for only 1.27Nm and servo and drive cost about $380
and a 750W is still only 2.39Nm with servo and drive about $600. The servos will be much faster but also way more expensive. Used within their
limitations the open loop steppers will work well for a fraction of the price.

6146

PoKeys / Re: Change Stepper to Servo

« on: October 27, 2017, 09:42:21 AM »

Hi,
34 size, that is 80mm square motors can be had in various lengths upto about 2000 oz.in (10 ft.lb or 15Nm). Low inductance windings promote
high speed torque in conjunction with a high voltage driver, ie minimize a steppers disadvantages.

American made Gecko drivers have a very good reputation, their 80V 7A models are around $150. Some experienced CNCers recommend Leadshine
AM 882 80V 8.2A drivers which are good value for money at $75.

6147

PoKeys / Re: Change Stepper to Servo

« on: October 27, 2017, 05:18:11 AM »

Hi,
whats wrong with the open loop steppers?...are they losing steps or too slow? Many people seem to think that a closed loop is going to solve 'lost steps',
certainly that's the advertising hype,  if a motor is loaded to the extent its losing steps then feedback is going to try to overcome that but feedback
DOES NOT make a motor any more powerful. If it was losing steps because it lacked the torque to do the job, it will still lack the torque, lose steps and
then fault out 'following error' feedback or not.

Servos, either brushed DC or brushless AC maintain their torque at high speed and beat stepper motors hands down above 1000 rpm or so. Stepper motors
have lots and lots of torque, for their size, at low speed. In fact steppers beat servos hands down at low speeds, for torque anyway.

Steppers and their drivers are way cheaper than good servos and except for high speed are as good or better than servos of the same size. If you really really
need your machine to go fast then pay up....and for your high speed production machine you'd be stupid to buy cheap crappy servos, you need good ones which
will last.

I repair welding equipment for a living and I see cheap Chinese electronics all the time...don't go there....they can and do make good stuff but its not cheap!

Craig

6148

PoKeys / Re: Change Stepper to Servo

« on: October 27, 2017, 04:49:39 AM »

Hi,
then get a torque vs speed diagram for it. If they're good that is the evidence, they could be recommended by God himself but I still want to see the torque vs
speed diagram BEFORE I spend anything!

Craig

6149

Mach4 General Discussion / Re: Switching to a Ethernet SmoothStepper controller.

« on: October 27, 2017, 03:20:48 AM »

Hi,
menardmfg is quite correct, if you want more inputs for buttons and switches then the PLC such as he has mentioned would work well and at a good price.

Any signals that are received by the PLC that need to be communicated back to Mach will have to pass through the Modbus serial link with a latency of
tens of milliseconds. That would be fine for a button to turn on the dust extractor fan say but if you wanted say an index signal back to Mach then the
latency will ruin the timing. Likewise for a probe signal your motors need to stop within microseconds (ideally) of a probe contact. So...probe contact event,
signals Mach 10ms later which signals the motion controller to stop the motors say another 1 ms later.....too late the probe has buried itself in your work
because the motors did not stop in time.

PLCs themselves are usually very fast, so it can detect an input event and very quickly control some output, within  tens of microseconds, usually more
than good enough for automation purposes. The trick here is that it can control its OWN outputs quickly but if it has to signal another device, like Mach,
THAT can be slow.

You need to decide if the extra inputs you want are going to be time critical. Two that I have mentioned are probe inputs and index signals for threading.
If those are part of your application or you may want them in the future then an ESS is a good way to go. If however you have no time critical inputs
the a PLC is good. The DL05 that menardmfg mentioned is good value and can be extended with analogue modules at very reasonable cost.

Craig

6150

PoKeys / Re: Change Stepper to Servo

« on: October 27, 2017, 02:25:11 AM »

Hi,
page 16 of the 57CNC manual shows the pinout of the 8 pin motor sockets.

You will need the Enable pin1, Dir pin3, Step pin5 and if you want the servo to be able to signal an error back to Mach then Error pin7.
Pins 1,3,5 are all DO5 type pins, 5V output, 100Ohm impedance, 8mA max current per page 19 of the manual. Should be able to drive the input opto couplers
directly. The Error input is DI5P type, 5V tolerant, pulled high by 10kOhm, page 19, and can be connected to the Alm+ output of the servo driver.

The connection is simple.

Do you really want those servos? Get a torque vs speed diagram before you buy them. If they can't supply one then stay away from that brand.

Craig