Messages

1411

General Mach Discussion / Re: Anyone try this device? -- U-HID (Universal Human Interface Device)

« on: January 03, 2009, 12:48:26 PM »

That is VERY cool, and cheap!

1412

General Mach Discussion / Re: Onboard parallel sucks, can't get parallel PCI card to work

« on: January 01, 2009, 01:05:44 AM »

To find out what port it's using, go to Device Manager:  MyComputer->Properties->Hardware->DeviceManager->Ports(COM & LPT)

Regards,
Ray L.

1413

General Mach Discussion / Re: setting a permanent home point

« on: December 30, 2008, 10:50:47 PM »

Hood,
   You're right, as usual.  X & Y do move together, once it's gone to safe Z.

Regards,
Ray L.

1414

General Mach Discussion / Re: setting a permanent home point

« on: December 30, 2008, 08:26:15 PM »

GoToZ will first move Z to the "safe" height, then move Y to zero, then move X to zero, then finally move Z to zero.

Regards,
Ray L.

1415

General Mach Discussion / Re: setting a permanent home point

« on: December 30, 2008, 05:10:23 PM »

My opinion, home  (limit)  switch's are as important as an E-stop.

Thanks, that's my opinion too. Although, in this case, the disaster would be a small one, this is just a tiny little Sherline.
Still, I haven't really looked at Mach's homing setup yet, because I can't apply it to anything. I'll get to the switches this week.

If you don't have home switches YET and you using steppers, simply place a dowel pin between a stop and the table and jog till it jams and the motor slips, do this in the same place everytime for all axis and press reference all
this proves to be repeatable to within 1 motor step size
Fit a clock and try it, you will be surprised
PS when the motor starts slipping stop movement within a second or so (try to keep this time the same and use the same slow jog every time)
thanks Friedrich

On my machine, that would result in a lot of sheared-off dowel pins, or worse.....

Regards,
Ray L.

1416

General Mach Discussion / Re: Work space parameters, Quandrants

« on: December 30, 2008, 01:52:24 PM »

You can set "zero" to be wherever you want it to be, so that is not a problem.  Decide where you want "zero" to be (presumably somewhere near the right-hand rear corner of the table), move the machine to that position, then zero the X and Y DROs.

Regards,
Ray L.

1417

General Mach Discussion / Re: setting a permanent home point

« on: December 30, 2008, 11:47:30 AM »

Yeah, I don't know what Mach is doing with the offsets. Since they have no steady Machine Zero to reference from, I feel like I'm getting different results with the offset buttons every time I hit one.
My earlier problem was that I thought the button marked "GOTO Z" was trying to return the mill to Machine Home.

The 'Abnormal Condition' blinking light is annoying, the edgefinder diagram on the offsets page seems like a waste of space, as are the TWO Tool Offset buttons with 'Gauge Block Height' settings. Those last two features seem like they're aimed at non-machinists.
I'd rather have the Work Offset and Tool Offset lists onscreen.

When you do "Go To Z", it send all axes to their *user* coordinate zero positions.  This has nothing to do with the machine coordinates, and it makes no difference whatsoever where machine zero is.  Machine zero is useful *only* for referencing a vise, fixture, etc. to an absolute position on the machine, so you can quickly and accurately return the user coordinate zero to an exact physical location on the machine after a power loss, position loss, etc.  It is a convenience that saves setup time.  Nothing more.  Once you're actually machining, unless you're writing some very "incorrect" G-code, the location of user coordinate zero relative to the machine coordinate zero is totally irrelevent.  All your G-code should be working only within the user coordinate system(s) as defined by one or more of the fixture offsets (G54-G59).

Regards,
Ray L.

1418

General Mach Discussion / Re: setting a permanent home point

« on: December 29, 2008, 09:24:38 PM »

I guess I just need to stop trying to run this thing and get home switches installed in it.
I haven't really spent enough time learning Mach's oddities, I keep trying to get it to run like a Haas.
Nothing seems to work like I expect.

If you don't understand how Mach deals with Home, zeros, and the different coordinate systems, adding home switches is not going to make it any less mysterious.  You *really* need to understand how Mach does these things to make good use of it.  Once you do, adding home switches may, or may not, add value for you.  I used my two machines for years with no home switches.  Now that I have them, I like them, but they are a convenience, not a necessity.

Regards,
Ray L.

1419

General Mach Discussion / Re: 2 Questions

« on: December 28, 2008, 12:06:41 AM »

...if you do not have both sets of co-ordinates in a fixed relationship to each other (here they are identical - which is the simplest relationship - i.e. the offset is 0.0.0) then any offsets in your program will not necessarily work correcty, and you will be left wondering why....

If you don't have home switches, under what circumstances will it matter what the machine coordinates are?  You shouldn't be running any G-code that cares....

Regards,
Ray L.

1420

General Mach Discussion / Re: 2 Questions

« on: December 25, 2008, 09:14:44 PM »

Oh, on the second question - it's asking if you want to save the offsets for the fixtures defined by G54-G59, etc.  Again, without home switches, there's really no reason for you to care.  Save them.  Don't save them.  Doesn't really matter.

Regards,
Ray L.