Messages

5211

Mach4 General Discussion / Re: Home Signal

« on: February 21, 2018, 01:32:51 AM »

Hi,
Op's description of the problem is not that the home switch event causes a fault but every time it triggers it gets logged. If he happens to be using the axis
as a spindle the logfile becomes loaded with these events.

Craig

5212

Building or Buying a Wood routing table.. Beginnners guide.. / Re: Motor Sound and Motor Temperature

« on: February 21, 2018, 12:42:06 AM »

Hi,
I run 23 size Vexta 5 phase steppers through low lash 10:1 planetary gearboxes. The gear reduction means I get great thrust and torque but fairly slow, and to make
up I run the steppers as fast as I can without losing steps.

The Vexta stepper drivers are powered direct from the 230V mains but the DC link voltage, that is the peak output voltage, is just over 150V and consequently
I can get them to run nicely at 2400 rpm. The rated current is 1.4A, but remember there are five phases as opposed to the more regular two phase steppers, so
is probably equivalent to about 2.5A in a two phase stepper.

I've found that at 1.4A the motors get uncomfortably warm when in active (highly active) service. I've reduced the current to 1A and found that even when working
flat stick for hours at a time they run about 60 degrees C. I've stuck a couple of aluminum heatsinks on each motor and have reduced the running temperature to about
45 degrees C.

I can only assume garylucas has very generously sized steppers that he can run without any heat build up.

A high voltage driver pays real dividends when trying to get a stepper to go fast without losing steps but is not responsible for heating. That is all about current.
Peak current determines peak torque, clearly any reduction in current reduces torque as well...not desirable but the heat build up is proportional to the
square of the current so even a modest reduction in current can help in the heat stakes.

Craig

5213

Mach4 General Discussion / Re: Entering Pulley Ratio in Mach4

« on: February 21, 2018, 12:18:06 AM »

Hi Joe,
how did you control the VFD when using Mach3?
To my knowledge there is two possible ways
1) An analogue (0-10V) voltage OR
2) Modbus (a serial communication protocol)

Craig

5214

Mach4 General Discussion / Re: Home Signal

« on: February 20, 2018, 10:47:33 PM »

Hi RT,
I can understand not wanting the logfile to get clogged up logging a home signal which is not being used.

If I understand the status of the thread is that if you disable the home signal then the homing routine fails
or at least objects and throws an error.

May I suggest instead trying unmapping the motor from the axis, this is possible programmatically. My hope is
that with the motor unmapped the homing routine will not throw an error. It may not even require you to disable
the home signal.

Craig

5215

Mach3 under Vista / Re: Issue with slave motor when running gcode

« on: February 20, 2018, 10:31:33 PM »

Hi,
there is a thread running on the main board which is remarkably similar, the same controller that apparently
wont slave another motor.

http://www.machsupport.com/forum/index.php/topic,36619.msg251297.html#msg251297

Craig

5216

Mach4 General Discussion / Re: Probe1, Probe2,Probe3, PMDX411

« on: February 20, 2018, 09:16:53 PM »

Hi,
oops sorry guys, misread it!

Craig

5217

Mach4 General Discussion / Re: Probe1, Probe2,Probe3, PMDX411

« on: February 20, 2018, 06:45:32 PM »

Hi RT,
the Mach4 plugin for the UC100 is not yet a year old. You probably need to email CNCDrives to get a definitive
answer.

Aside from anything else you can't have many pins left to hook up other probes?

Craig

5218

General Mach Discussion / Re: I need use the motor brushless with 5 axis stepper card

« on: February 20, 2018, 01:13:19 PM »

Hi,
the ESC uses a PWM popular with RC. It has a pulse width of between 1 and 2 millisecond refreshed every 20 milliseconds or so.

Mach3/BoB does not produce that sort of signal naturally. You will have to have a circuit to convert standard PWM (duty cycle) to RC style. As Mike said:
Google is your friend.

To use this motor as a spindle is likely to cause it to overheat.

Craig

5219

Building or Buying a Wood routing table.. Beginnners guide.. / Re: Motor Sound and Motor Temperature

« on: February 20, 2018, 01:11:36 AM »

Hi,
yes it is quite common for steppers to get hot, 80 degrees C is on the hot side. Many drivers have the option to set the output current.
Its never advised to set for more current than the motors rating but you can set less. To reduce the current to about two-thirds or maybe
three-quarters of rated can markedly improve the cooling situation without unduly affecting torque.

Another common feature with stepper drivers is the ability for the driver to automatically reduce current if the motor is idle. The holding torque is such that at
idle there is ample torque to keep the motor in location. it is possible to reduce the current, usually to a half and reduce the heating.

Even at idle there is current in the motor and any variation of that current can produce noise. At full step or half step at idle I wouldn't expect any noise.
With microstepping there could be a small fluctuation and noise as a result. I still would expect no more than low hum, louder than that may indicate a problem.

Craig

5220

General Mach Discussion / Re: Z axis stopped working

« on: February 19, 2018, 10:40:01 PM »

Hi,
are the drivers separate or all on one circuit board?

My suggestion is feed the Z axis step and dir pulses to the X axis driver and see how the X axis motor responds.

Craig