Messages

7281

General Mach Discussion / Re: G03 arcs are smooth, G02 arcs are jerky. Help!

« on: December 24, 2016, 05:17:21 PM »

Hi mikep,
I can't really think of anything that would explain it, the code looks OK.

May I suggest some experiments that might isolate the problem.

With a blank in the machine why don't you try MDIing some arcs to see if the fault occurs. It would establish whether its
faulty code or whether something peculiar is happening with the machine.

It occurs to me that if the arcs are OK in one direction but falter in the other then one axis is struggling to step in the reverse direction.
I note that you've posted before on this subject and have stated that linear moves in either direction are fine which would tend to make you
think that my thought is wrong. I don't know whether your BOB has LEDs on the outputs but mine does. I've noticed that if you call a move,
say the X axis, to the right, the DIR pin, on my machine at least is low, and it stays that way until the end of the move, and in fact will stay
that way indefinitely after the move until Mach changes it to  high when called on to move left. That is to say that the DIR pin is persistent.

During arc moves it may not be. What I'm thinking is that the DIR pin is changing but is not established long enuf before the STEP pulse arrives.
I use Vexta drivers and they have superb documentation and there is a specification for how long the DIR input must be established before the
STEP input goes high and steps the motor, its not long, about 0.5us from memory. Maybe one of your drivers is a bit slow.

Try some MDI acrs to gets the fault to recur. Then on the motor tuning page try upping the direction pulse a bit maybe a few us and see
whether it cures the fault.

Craig

7282

General Mach Discussion / Re: C10 BOB use with 12VDC Relay

« on: December 24, 2016, 04:47:05 PM »

Hi,
not directly, the TTL buffer chip inside the BOB is STRICTLY limited to 5V.

A couple of ways to achieve it:
1) use a little 5V relay and use its contacts to turn on the 12V one,
2) use an NPN transistor or Mosfet as the 12V switch which can be turned on by the BOB output, requires one resistor, one transistor and one diode.

Either way you will still require a 12V power supply to energise the relay coil.

Craig

7283

VB and the development of wizards / Re: I need a wizard that will route a straight cut

« on: December 23, 2016, 09:12:14 PM »

Hi,
why a wizard and not just plain old MDI?

Lower the bit to the depth of cut you require at the start of the cut,
G1 Xnnn Ymmm Fppp   where nnn,mmm are the cords of the required end point at federate of ppp,
withdraw the cutter above the work, job done. Need to allow for diameter of your routing bit of course
but that calc shouldn't even require a calculator.

Craig

7284

Mach3 under Vista / Re: Z-Plate is grounded!

« on: December 23, 2016, 08:55:40 PM »

Hi ,
found the document required on the cnc4pc website. The section your interested in is 7.4 'Other Connections'.

Note that it does say that you require the pullup jumper to be high. This is probably contrary to your other inputs
on pins 10, 11, 12 and 13. If you're not using those then just change the jumper. Other than that you will have to use
the 'added pullup resistor trick'.

If you put a 4.7kOhm resistor from the pin to a 5V source (not sure how you've jumpered the com) then the pin will float
at 2.5V. Probably enuf for Mach to recognise a logic high. If you use a 1kOhm resistor it will float at 4.1V, easily good enuf
for a logic high that Machs expecting. Means your probe will have to sink 5mA to pull the pin low when it makes contact,
no problems there unless your probe wiring is really shonky. Note the 1kOhm resistor will dissipate 25mW when the probe
contacts so even a 'baby' resistor will do the trick.

Let us know if that solution works.

Craig

7285

Mach3 under Vista / Re: Z-Plate is grounded!

« on: December 23, 2016, 08:26:10 PM »

Hi,
I'm guessing the pin on your BOB has a pulldown resistor. So in absence of a current source it will always be low and
because Mach is expecting an active low per your setting it determines that the probe has contacted.

I don't have or use a C10 board but recall looking at the circuit diagram and set up notes for another bloke who was having
trouble getting going. If memory serves there is a jumper that you can reposition that will now pull the pin high and your
problem is solved. Only one drawback is that one jumper controls the pullup/pulldown behaviour of all your input pins
so fixing your probe problem may well break your Estop/Limits/Homes or whatever else you have hooked up.

You could add another resistor to the pin from a 5V source and if the resistance is low enuf it will 'beat' your pulldown
and you have a solution that doesn't upset your other pins. Before I could recommend I would want to see the circuit diagram
of the pin to ensure that no part gets hot.

Let me know if any of this makes sense and I will try to firm up my recommendation.

Craig

7286

General Mach Discussion / Re: Please help me remove the red lights!

« on: December 23, 2016, 08:06:19 PM »

Hi Richard,
again I cannot be absolutely clear about this because my setup is different.

While 'Limit Overide' is in operation if you called either by jogging, MDI or faulty homing direction/logic yes indeed the machine
can run out of limits and crash. It is for this reason I suggested that the screw heads be shifted inboard a wee bit so that if
some fault of yours or your homing logic happens you will have time to Estop before the crash.

Unless you temporarily disable the limits then when homing and the switch is activated the machine stops. Imagine the situation
that your intended home position for X is at the far right of travel and prior to homing the table is several inches to the left
of that. When the axis homes it does so in the direction and speed that you nominate on the Config/Homing-Limits page.
Should you have the direction setting wrong then the table will travel to the left expecting to find a home switch to trigger
a stop. If it doesn't find one it may well keep on going and crash because the limits are disabled. Yet if the limits are not
disabled and the axis homed in the correct direction ie to the right then as soon as it triggers your home/limit switch the
machine will stop and you can't continue to home the remaining axes.

When I was setting up my machine all that logic baffled me and that's how it came to be that I have separate home switches,
one for each axis, it just made sense to me at the time. Later I realised that home and limits could be combined with possible
savings in switch numbers, wiring and input pins required I'd gotten so used to what I had that I never changed it. You
know what they say 'there's nothing so permanent as a temporary fix'.

Craig

7287

General Mach Discussion / Re: oval circle

« on: December 23, 2016, 03:13:24 PM »

Hi jajohnsen,
I remember when I was a boy my uncle teaching me to use the lathe. He set up a dial gauge between the two lathe rails then asked
me to grab the rails and try to spread them apart and lo and behold I got about 1-2 thou of movement. I was gobsmacked, how could
I at nine years old deflect such a beefy casting! The concept of flexure of what appears a rigid component has stayed with me ever since.
I am inclined to forget the lesson until I try to work out why some operation that didn't go as I'd hoped only to realise I was relying on components
being absolutely rigid and unless Hookes law is repealed that's never the case.

Craig

7288

General Mach Discussion / Re: Please help me remove the red lights!

« on: December 23, 2016, 02:51:54 PM »

Hi Richard,
I'm not familiar with the logic and wiring of combined Home/Limit switches. I have three independent Home switches
on three input pins and all the six Limit switches in series on a separate pin.

The Home switches trigger a few mm inside the Limit and consequently the Limits are never triggered when I HomeAll
unless one of my Home switches is faulty.

In Mach3 there are buttons 'Auto LimitOveride' and 'OverideLimts', I've seen them on the Settings page but have never had
reason to use them but I believe their use is when you have Limits/Home combined. If you are homing then you must at least
temporarily tell Mach to ignore the limits otherwise it will 'stop on limit' and never get the chance to complete its homing
sequence. Does that sound like what's happening? In that case it may just be that a setting has changed and if you restore
it things will go back to normal.

Craig

7289

Mach4 General Discussion / Re: re-mapping motors and home switch inputs through lua script

« on: December 23, 2016, 02:26:16 PM »

Hi Ya-Nvr-No,
kool, very kool indeed!

When you ran the script did your reassignments show up on Axis Mapping page?. They don't when using sim on my laptop.

I can map motor4 to the X axis as a slave to motor 0 but it doesn't show on the table and if I inspect the table the table
takes precedence an overwrites the assignment made in my script. How I tumbled to this was that I disabled all
axes and unmapped all motors on the table, and then no axis movement would occur when I issued any MDI commands.
Then I would run my script which enabled axes 0,1,3 and mapped motors 0 and 4 to axis 0, motor1 to axis 1, motor2 to axis2
and the sim diagnostic would show motor movements when I issued MDI moves. When I went back to the Configure/Mach/Axis Mapping
page none of my assignments were there and when I clicked OK to get out of there I was back to a totally disabled machine.

Once I understood this behaviour the rest of my experimentation went a lot smoother. It forms the basis of my suggestion that
the existing enable/mapping states should be read prior to any manipulation for squaring and once done the enable/mapping
states should be restored so the assignment table reflects the machines actual state.

I haven't fiddled yet with any to the SetHome/IsHomed/Home Complete type API commands yet but from your post I'm sure they
will prove to be equally valuable.

Have to say that M4 is VERY crafty! Light years ahead of M3.

I think Cal892 has everything he needs to script his squaring procedure, very kool indeed.

Craig

7290

Mach4 General Discussion / Re: re-mapping motors and home switch inputs through lua script

« on: December 23, 2016, 06:36:34 AM »

Hi,
I have been experimenting with M4 in Sim and discovered a few useful things.

First is that if you go to the Configure/Mach/Axis Mapping tab and even if you change nothing as you click OK then those
settings are made. I have tried:

mcAxisEnable(inst,0,true); it as expected enables/disables axis 0 in this example,

mc.mcAxisUnmapMotors(inst,0); it unmaps all motors from axis 0 in this example,

mc.mcAxisMapMotor(inst,0,0); it maps motor0 to axis0 in this example;

mc.mcAxisMapMotor(inst,0,4); it maps motor4 to the axis0, and this is the kicker now two motors are mapped to axis 0 exactly as Cal requires
and can be temporarily undone by:
mc.mcAxisUnmapMotor(inst,0,4); there again as Cal requires. Under this circumstance motor 0 is still mapped and could be jogged/MDI'ed into position
and then motor4 could again be slaved back to motor0. Don't bother to go to the Configure/Mach/Axis Mapping tab it won't reflect your hand coded
mappings/unmappings and worse will overwrite them just to screw with your head!.....Go on...tell me you didn't go there to try for yourself and now
all your mappings are up the duff right, I bloody told you!

I have been observing the results of various experiments with the sim diagnostic pinned to be always on top, really useful. The reason I chose motor4
rather than motor3, the next spare one, is that the velocity trace which should be solid black doesn't show up whereas all the others do. The string of
position data in the pane above suggests that motor3 is moving as anticipated just that the velocity trace doesn't show, a bug maybe.

What I propose is that if Cal were to write a macro it would in the first instance read ALL the existing enable states and mappings. Then home all axes,
uncouple the master/slave pair, jiggle the remaining motor until square and recouple. Then as an important last before exiting the macro restore
ALL the enable states and mappings to avoid having some hapless operator go to the Configure/Mach/Axis Mappings tab and inadvertently change
everything.

I am still of the opinion when you set up your controller that the two motors would have to be assigned independent 'channels'. The experimenting
I've done suggests that it is possible to have Machs core run the master/slave assignments and they can programmatically be manipulated. This would
obviate the need for the motion controller plugin to handle squaring. A good result I think!

Craig