Messages

7001

General Mach Discussion / Re: 1/2 speed spindle

« on: May 25, 2017, 02:24:57 PM »

Hi.
yes you'll need a differential line driver to run at full speed at max resolution but you don't really need to do you?

I mean that currently with 10000 count per rev you can drive your spindle to location 2.16 arc minutes apart.....might be appropriate
for a ballscrew on an axis but do you need it for a spindle?. If not then use the electronic gearing to reduce the resolution to something
sensible, say 15 arc min, and you'll probably run single ended OK.

P9=1
P10=10
for gear ratio 10:1, ie 1000 count rev for a pulse rate of 41.66 kHz at 2500 rpm.

Craig

7002

General Mach Discussion / Re: 1/2 speed spindle

« on: May 25, 2017, 04:29:11 AM »

Hi,
do you have a scope? If so probe the pulse input to the drive and confirm th pulse rate, should be 416 kHz with 10000 count per rev and 2500rpm.

Check parameters 4, 8,9 and 10 for correct setup.
P4=0 for position control
P8=0 for step/direction
P9=1 gear ratio numerator
P10=1 gear ratio denominator

What have you set P20 to? Should be set to rated speed. For some reason P62 is also rated speed.

Let us know what you find.

Craig

7003

Mach4 General Discussion / Re: axis change

« on: May 25, 2017, 12:45:48 AM »

Hi,,
do you want to change it in the Gcode or just have the machine operate as if X is Z etc?

If the later you could reassign a motor to an axis.

Craig

7004

General Mach Discussion / Re: 1/2 speed spindle

« on: May 24, 2017, 02:46:41 PM »

Hi,
sounds like the servo drive is interpreting your pulses as CW/CCW or quadrature rather than step direction.

Craig

7005

General Mach Discussion / Re: System Reboot - time to start from scratch

« on: May 24, 2017, 02:54:52 AM »

Hi,
the real question is whether you want to stick it out. Hobby CNC doesn't come easy, there are lots of pitfalls and things to learn.
If you are the sort who expects it to come easily or quickly without having to learn all sorts of stuff then CNC is the wrong hobby for
you.

I have on and off been into model aircraft since I was a lad. I've watched people come along and think 'this is great, I'm going to build one'
Then when they fly the thing it gets broken, they always do eventually, and they are very disillusioned and depart forever. What gave them the idea
that gravity doesn't apply to their models I've no idea!

The bottom line is that CNC rewards those who stick it out. There are some good resources out there, particularly this forum, which will make it all
possible and the sense of satisfaction attending a good result is amazing.

If you wish to continue then you need a suitable PC. If you have a late model one you will need an external controller in all probability. Shell out some
bucks and get on with it.

Craig

7006

General Mach Discussion / Re: Changing Kernel Speed in Mach 4

« on: May 24, 2017, 12:50:11 AM »

Hi,
thinking a little more about your question...the kernel speed is the 'clock rate' of the internal
software driven timer used by Machs parallel port. With an external motion controller like the
ESS there is no timebase internal to Mach, the external controller will no doubt have a clock as a timebase.
The ESS has a max pulse rate of 4Mhz and guess that it is the equivalent of kernel speed. 4 MHz is way
way way quick...

Craig

7007

General Mach Discussion / Re: Changing Kernel Speed in Mach 4

« on: May 23, 2017, 11:47:06 PM »

Hi,
to my knowledge there is no such page on Mach4 with ESS. Its the same combination I use and I've
never set the kernel speed in the same manner as Mach3 with PP.

Craig

7008

General Mach Discussion / Re: Need new small computer

« on: May 22, 2017, 08:47:18 PM »

Hi,
either. Ethernet is fastest and has better latency performance. Ethernet is transformer isolated as
standard, USB can be isolated but need to be specified. Whether galvanic isolation is important is
a moot point.

I would recommend that if you buy one that you get one that has a Mach4 ready plugin in addition to
a Mach3 plugin. At this time the manufacturers whom offer cheap ($100-$200) Mach4 ready external
controllers are Warp9,PMDX, PoKeys and CNCdrive. All of these companies have been around a while
and all enjoy a good rep for backup. You need to read and interpret the specs and weigh those against
your requirements/expectations to make a choice. The good news is that any of them are pretty damn
good. Avoid the cheap-no-name stuff, the forum is littered with posts of people trying to get these
pieces of junk running.

Craig

7009

General Mach Discussion / Re: Need new small computer

« on: May 22, 2017, 03:07:54 PM »

Hi,
I've used a dual core Atom mini ITX for Mach for several years without trouble.

I installed Windows 7 Embedded 32 bit as OS and ran two PP with Mach3. Despite on-board graphics it worked well.
More recently have upgraded to Mach 4. While the Atom can be very slow to load large Gcode files it otherwise runs
fine. Note that I upgraded to an external controller at the same time.

Truth is that you don't need a 'whiz bang' PC to run Mach, one that runs without interruption or hesitation due to hardware/software
conflicts is whats required. I think the NEXBOX will be fine. You will need an external controller to use Windows 10 as OS.

Craig

7010

Mach4 General Discussion / Re: Home, Limits, Soft Limits

« on: May 21, 2017, 12:40:46 AM »

Hi Ron,
yes you've got that right.

For instance if you're X home switch is at the extreme right of travel with machine co-ord of X=0, by definition of 'home',
then the other end of the X axis will be positive using conventional direction notation, say X=36, for  36 inch travel machine.
You would enable soft limits for the X axis with the softmin=0 and softmax=36. Likewise for other axes.

Note that soft limits work on machine co-ords. If you have a piece of material in the machine say 6 inch square you would
manually drive to the lower lefthand corner and 'zero' X and Y. The DROs now represent the position of the cutter relative
to the lower lefthand corner of the material, known as the 'work co-ords'. Mach still retains knowledge of its own machine
co-ords however just it doesn't display them, unless you ask, as it just confuses you.

You can see the relationship of the DRO position, the machine co-ords, the work offset and others on the machine diagnostic tab.

You can now implement limit switches as well. I assume from the way you worded your post that your three home switches are
on separate pins? To double as a limit switch each home switch will also have to be at the very end of travel. You will now require
a limit switch at the other end of travel, one for each axis for three switches.  If you have enuf inputs you should assign
each limit to one pin. So your X axis home switch is lets say pin 11, your X++ pin will also be 11 but your X-- (limit switch) may
be 12 say.

When referencing your machine you wish Mach to regard pin 11 as Xhome but once finished homing regard it as X++, ie a limit.
I have separate homes and limits so am only guessing here...when 'RefAll' is in operation limits are ignored, thereafter all limits
are active and operation of any of the six switches will cause an Estop.

In order to prevent the machine from banging into the limits its common to specify softlimits just inside the hard limits and permit
a graceful shutdown. Using the example from above X softmin=0.5 and X softmax=35.5.


Craig