Messages

5791

Mach4 General Discussion / Re: Reference all home help.

« on: November 29, 2017, 03:57:01 AM »

Hi,
I suggest putting this in your profile/macro folder. Allows you to debug and work on it. Once you get it polished then we'll put it in the screen load script
and attach it to the button.

Craig

5792

Mach4 General Discussion / Re: Reference all home help.

« on: November 29, 2017, 03:53:39 AM »

Hi,
this code seems to work...haven't really tested it fully

Code: [Select]

function GoCenter();
local inst=mc.mcGetInstance();
local Xhand=mc.mcRegGetHandle(inst,'iRegs0/Xcenter');
local Xcenter=mc.mcRegGetValue(Xhand);
local Yhand=mc.mcRegGetHandle(inst,'iRegs0/Ycenter');
local Ycenter=mc.mcRegGetValue(Yhand);
local Zhand=mc.mcRegGetHandle(inst,'iRegs0/Zcenter');
local Zcenter=mc.mcRegGetValue(Zhand);
local homed=0;
local enabled=0;
if (mc.mcAxisIsEnabled(inst,mc.X_AXIS)==1) then enabled=enabled+1 end;
if (mc.mcAxisIsEnabled(inst,mc.Y_AXIS)==1) then enabled=enabled+1 end;
if (mc.mcAxisIsEnabled(inst,mc.Z_AXIS)==1) then enabled=enabled+1 end;
local Xhomed,rc=mc.mcAxisIsHomed(inst,mc.X_AXIS);
local Yhomed,rc=mc.mcAxisIsHomed(inst,mc.Y_AXIS);
local Zhomed,rc=mc.mcAxisIsHomed(inst,mc.Z_AXIS);
if Xhomed==1 then homed=homed+1 end;
if Yhomed==1 then homed=homed+1 end;
if Zhomed==1 then homed=homed+1 end;
if (homed+enabled)==6 then
    mc.mcCntlGcodeExecuteWait(inst,"g53 g0 z"..Zcenter.."\n g53 g0 x"..Xcenter.."y"..Ycenter)
end
end
if (mc.mcInEditor() == 1) then
    GoCenter()
end

Craig

5793

Mach4 General Discussion / Re: Acceleration Settings

« on: November 29, 2017, 03:11:47 AM »

Hi,
my PCBs are for various uses. The one which is difficult to make and very very expensive if I were to have it made for me is a heavy copper board,
the copper layer is 420um thick (0.42mm). That is 12 times thicker than normal. You can get them etched but double side boards with heavy vias
can cost $1000 per sq foot.

I have broken a lot of tools trying to make theses boards but am getting the hang of it now. When I go back and count the number of small endmills (16 thou
and 20 thou) I have not in fact broken hundreds, about 60 over three years.

They are carbide tools and the trick is to cut the barest minimum of fiberglass as it dulls tools big time. I use a software tool called Autoleveller to assist cutting
the barest minimum I have to.

Don't slow the tool down, spin it as fast as you can. If you are using inches the .001 (1 thou) chip load is too much.

My post recommends 1% of diameter....0.01 (%)x 0.02 (diameter)=0.0002    read that again...that is two tenths of a thou. What you are proposing (1 thou) is
five times what I'd recommend. You will break it for sure.

For a slotting toolpath the depth of cut should be 25% of the diameter. Slotting is very challenging, if you try to slot full depth in one pass you will break tools
or I certainly did. I also reduce the feed rate to half when slotting and reduce plunging to a quarter.

My wee mill has low lash (less than 2 arc min) planetary reduction boxes on the steppers and so the rapids are slow (1200mm/min) but the accelerations are high
(375mm/sec/sec). Quite frankly CV and accel mean squat when trying to establish the correct conditions for long tool life with these micro tools, its about matching
the chip load to the strength of the tool and clearing chips to reduce the torque drag. About half the breakages I've suffered are due to the spindle twisting the tool
off. The other half is where the feed over runs the cutting ability and snaps it off sideways.

Craig

5794

Mach4 General Discussion / Re: Reference all home help.

« on: November 29, 2017, 02:36:19 AM »

Hi,
writing code as we speak.

Yes the function can only work IF the machine has been homed or referenced otherwise you could crash. Also trying to stop the function from running if
any of the axes are not enabled otherwise the GUI will block.

You could hard code the numbers in the code but if you ever wish to change them you'd have to delve into the code to change the numbers. If you use
registers you can use the Diagnostics of Mach and edit the numbers directly and easily, no messing around editing Lua code and recompiling.

If you go to Configure/Plugins/Regfile and create three new registers (the little green plus sign adds a new line)...

Craig

5795

Mach4 General Discussion / Re: Reference all home help.

« on: November 29, 2017, 01:03:50 AM »

Hi,
oops... posted before I'd completed...

LUA Syntax:
enabled, rc = mc.mcAxisIsEnabled(
      number mInst,
      number axisId)

and:

LUA Syntax:
homed, rc= mc.mcAxisIsHomed(
      number mInst,
      number axisId)

Craig

5796

Mach4 General Discussion / Re: Reference all home help.

« on: November 29, 2017, 01:01:19 AM »

Hi,
couple of preliminary items:
1) If the machine has not been referenced you CAN'T use the Go_Center function. When you first turn Mach on the machine co-ordinates could be any where.
If the machine drives to a specific machine co-ordinate location it could easily go outside its envelope and crash. Soft Limits won't help either as they ONLY make
sense and do any good once the machine has been referenced.
2) You will direct the machine to execute some Gcode but if one of the axes is not enabled then the machine can't do as you've asked and it will hang up and
you'll have to crash it to get it to unblock, not desirable. Before executing Gcode need to establish that all required axes have been enabled so the code doesn't block.
3) The machine co-ordinates of the center of the table should be held in registers. It makes it easy to tweak, just edit a register rather than delve into a script.
4) The Go_Center function should probably go in the screen load script rather than the signal script or a macro, the screen load script functions are visible throughout
Machs GUI. Having said that I propose to write it as a macro initially, it allows a convenient set of editing and debug functions.

Two API calls of use to us:

5797

General Mach Discussion / Re: CNC Router "Stutters/Loses Position" on Faster Feed Rates

« on: November 29, 2017, 12:33:12 AM »

Hi,
there is ONE right number for your machine...it is the number of pulses that Mach has to issue to get the axis to move one unit, whatever units you
choose. If you put the wrong number, say 10000, when your machine  is actually 5080 Mach will issue 10000 pulses and you expect the machine to move one
inch but it in fact moves closer to two inches.

What is the native units of your machine?

Craig

5798

General Mach Discussion / Re: CNC Router "Stutters/Loses Position" on Faster Feed Rates

« on: November 28, 2017, 10:58:22 PM »

Hi,
I think ger21 is right, without the correct steps per unit you could be demanding that your stepper go way too fast and it will
fail to do so and quite probably give you the symptoms you describe.

You cannot guess about these things, if its not right, everything else is rubbish.

Microstepping is used because it results in smoother motion of the stepper motor. Most people  use '8 micro steps' or maybe '16
microsteps'. You could use even more if you wish but then Mach may not be fast enough to drive the machine to high speeds.
As a consequence 8  or 16 microsteps is a good compromise. It sound like your driver is set to '2 microsteps'. I really want you
to study the manual to resolve this. I would set the switches to '8 micro steps' which is the same as 1600 pulse/rev or
1600 steps/rev.

Note that is steps per rev, so if the machine moves 8mm per revolution of the screw then the steps per mm would be 1600/8
or 200 steps per mm, or in inches, 200 x 25.4= 5080 steps per inch.

What are the native units of your setup? Look under Config/Select Native Units....you can use either but once you choose it
then leave it alone. If you want to run some Gcode in inches use G20 or in mm use G21, don't fiddle with the native units.

Craig

5799

General Mach Discussion / Re: CNC Router "Stutters/Loses Position" on Faster Feed Rates

« on: November 28, 2017, 09:36:26 PM »

Hi,
is that 400 pulses per rev? That would be called 'half-step'. A normal two phase stepper is 200 pulse/rev.
At 'half step' 400 pulse per rev. At '4 microstep' 800 pulse per rev. At '8 microstep' 1600 pulse per rev.

If that is correct your steps per mm would be 400 (pulse/rev)/ 8 (mm/rev)=50 steps per mm.
If in inch units 50 (step/mm) x25.5= 1270 steps per inch.

Seems like a large discrepency between what you've set and these numbers.

Can you post the manual for your drivers? I suspect, as it stands, there is some confusion between microsteps and pulses
per rev.

Craig

5800

General Mach Discussion / Re: CNC Router "Stutters/Loses Position" on Faster Feed Rates

« on: November 28, 2017, 09:00:42 PM »

Hi,
what number of microsteps?

Craig