Messages

811

General Mach Discussion / Re: Bridgeport mill and back gear spindle reversal

« on: December 21, 2009, 10:11:53 PM »

QUOTE  "does a spindle speed call automatically switch pulley # base on set values in the spindle set up"
 
NOPE...not here anyway.
Probably could be made to with a fancy macro though.
Rays dept.

I'm not aware of any way to automate pulley selection through macros.  Doesn't mean it can't be done, but I'm not aware of any "hooks" into the spindle control that would allow it.  Possibly through a plug-in?  But one thing I'm learning (painfully) lately is that trying to do things in Mach3 that are not commonly done, you're pretty much guaranteed to end up "fighting city hall".  I've had a real time working around bugs and limitations in Mach3 to make the knee do tool length compensation.  I hate to think of the problems you'd run into trying to make spindle control "smart".

What I do on my machine is run the G-code through a pre-processor that makes "optimum" selections of pulley, motor speed range, and VFD frequency, to minimize the number of pulley changes through an entire program, so I don't have to change pulleys every time I change tools.  In most cases, I can run a whole job with no pulley changes.

Regards,
Ray L.

812

General Mach Discussion / Re: Bridgeport mill and back gear spindle reversal

« on: December 21, 2009, 09:01:57 PM »

I have a Bridgeport milling machine and how can I tell Mach software to invert the spindle direction in Back gear using switch hooked to the lever

The "Reverse" checkboxes in the pulley setup are there for exactly that reason.

Regards,
Ray L.

813

General Mach Discussion / Re: Using The Knee For Tool Length Comp....

« on: December 19, 2009, 06:36:39 PM »

I now have all the macros I need to use probing to initialize the tool table, and apply the offsets when milling.  Hopefuilly, tomorrow I'll have the time to acrually "use them in anger" for the first time!

Regards,
Ray L.

814

General Mach Discussion / Re: Is this a valid line of VB script?

« on: December 19, 2009, 03:22:00 PM »

I'm troubleshooting an OEM macro (that seems to work in version .029 but not in version .032) with little VB knowledge. It contains a line that I can't figure out:

"wait = GetOEMLED(11) = 0"

Is this line with two "=" symbols valid and if so can someone tell me what it is trying to do?

Thanks - Terry

It would be better written:  "wait = (GetOEMLED(11) = 0)".  It is valid, but perhaps poor coding practice.  GetOEMLED(11) = 0 will be evaluated as a boolean expression, returning TRUE if OEM LED 11 is Off (0).  So, wait will be set to TRUE (non-zero) if LED 11 is Off, and FALSE (zero) if LED 11 is on.

Regards,
Ray L.

815

General Mach Discussion / Re: Using The Knee For Tool Length Comp....

« on: December 17, 2009, 02:57:56 PM »

Hood,

No reason you can't use the gauge line as the reference, and my understading it that's the way it is done on VMCs.  You'll just need to modify which way the knee moves when changing tools.  But I don't understand how you know when it's safe to turn off length compensation, and not risk crashing the tool.  But, then, I don't even know enough to know what I don't know.  I only barely know what I'm doing here.  I've never worked on a "real" machine.

Regards,
Ray L.

816

General Mach Discussion / Re: Using The Knee For Tool Length Comp....

« on: December 17, 2009, 12:55:16 PM »

Well, it really is just that simple.  Just tested the macros, and it all works just as it should  you can actually define the tools any way you like, but for safety sake, it really is best to make an offset of 0.000 correspond to your longest tool, so there's no danger of a crash when you turn comp off.

The macros I'm now running are below.  M843 applies the comp, M849 removes it.  Use these in place of G43 and G49.  With M843 use the P argument to specify the tool table entry whose length offset is to be applied.  You may find the "extra" moves in there confusing - I do this because I have a lot of backlash in the knee - bevel gears and a leadscrew, rather than a ballscrew - so I get most repeatable positioning by moving the knee up to final position.  So, if a down move is required, I move down a little past the target position, then back up to the target position.  This gives me excellent repeatability.

Regards,
Ray L.


Oops!  Posted the wrong M843 macro.  Now fixed.

817

General Mach Discussion / Re: Using The Knee For Tool Length Comp....

« on: December 17, 2009, 10:36:41 AM »

Hi Ray, I must say I am really looking forward to seeing this working.
With the onset of cold weather I have been back in the shop trying to get to the point that I can install the knee drive.
I can really see the value in this as I have a job where I have a 7 inch tool and then a 1 inch tool. Lots of knee cranking!!!!

I may have enough tool holders that I can have a persistent tool table, will that make any difference in how this gets set up.

I wasn't sure I agreed with the negative tool offset but now I  have to agree with it since you explained what happens when you cancel the tool offset.

Even if you have to measure the tool lengths manually, this will be a great addition to any knee mill. I will hopefully be able to do it automatically soon.

Keep on plugging away at it.

Mike

Mike,

We'll know within hours...  All works fine in simulation, so I don't expect any surprises.

Regards,
Ray L.

818

General Mach Discussion / Re: Help with Auto tool zero macro?

« on: December 17, 2009, 10:03:22 AM »

M-macros are created simply by naming the file M*********.m1s.  So, if you want to run a particular macro as M199, put it in a file named M199.m1s.

G31 does obey the acceleration specified for each axis, so it *will* over-shoot if you probe at high speed.

Regards,
Ray L.

819

General Mach Discussion / Re: Using The Knee For Tool Length Comp....

« on: December 17, 2009, 09:51:15 AM »

If  you used the longest tool method then it would be the same but only if you were sure you would never ever have a tool in that was longer than the reference tool. I am not 100% sure but I seem to remember that you can have positive length offsets or negative length offsets but not a mixture of both, could be wrong though and if I am then it wouldnt matter a toss which way things were done.

Hood

Hood,

Mach3 doesn't care whether the tool table offsets are all positive, all negative, or some of each.  And, in this case, circumventing G43 with a macro, it really doesn't matter.  Mach3 v4 will use a completely different setup, and probably will allow G43/G49 to invoke VB macros.

Regards,
Ray L.

820

General Mach Discussion / Re: Using The Knee For Tool Length Comp....

« on: December 17, 2009, 09:47:18 AM »

Just wondering, from a practical standpoint, would  it not be easier to set the reference tool up to the gauge line on your taper and have positive offsets for your tools? My thinking is you can never have a shorter tool than your gauge line but if you were using a max length tool as the reference then it may be in the future you get a tool that is longer and thus will have to redo everything.

Hood

Hood,

I considered that, but the problem is, what happens when you do a G49 (or M149 in this cas)?  The knee would want to return full up, which will pretty much guarantee a crash unless the tool is first removed.  By referencing to the longest tool, a G49 will lower the knee, which will always be "safe".

Right now, I setup the tool table before each job, so if I get a longer tool at some point, I make a longer reference too, and I'm back in business.  I don't have enough holders to have a "persistent" tool table.

Regards,
Ray L.