Messages

891

Mach4 General Discussion / Re: Using M7 to run a script in a command window.

« on: January 18, 2022, 05:35:19 PM »

Hi,
What are you wanting to achieve?. Are you just trying to turn a solid state relay on or off?

m7 and m9, note the deliberate use of lower case....it is important as I will explain, are built in m-codes and are generally left alone, otherwise you risk upsetting Machs internal behavour
to those m-codes. That is not to say you cannot write your own but now Mach will execute YOUR m-code and if its not complete or the functionality differs from the standard m-code
you have created a f...up.

Its common practice that if you write custom m-codes that you number them 100 and above....as that will avoid clashing with any internal m-codes.


When Mach encounters an m-code in a Gcode file, it first parses the block to ALL lowercase, strips out leading zeros and strips out whitespace.
Thus: M 07 will be reduced to m7....and then Mach will search for that function, in the first instance in your profiles Macros folder, and if it does not find it there it will search up the file tree until it finds
a compliant macro. For this reason its a good idea to create and write macros using lowercase etc so that there is no possibility that Mach misses the macro you intended to run.

If you are just trying to turn on or off a solid state relay however you are going off the deep-end, there is a much MUCH simpler way to turn on or off a relay.

Craig

892

General Mach Discussion / Re: Manual pulse encoder & mach3

« on: January 18, 2022, 12:40:42 PM »

Hi,
I bought this:

https://www.ebay.com/itm/201195367332

It might be old but great quality.

Craig

893

Mach4 General Discussion / Re: Glitch on X movements

« on: January 16, 2022, 05:55:11 PM »

Hi,

first about accl deccl , the first improve its to add external resistor this improve a lot but and its long story between me and craig

Can't with Clearpath servos, there is no place to hook up a braking resistor....I can do so if I want or need with my Delta servos because they have a separate drive
but Clearpaths do not have a separate drive.

As it turns out I only use 60% of the acceleration that my servos could provide, and that's only its rated acceleration, its overload is 500% more than that! Despite my machine weighing over 800kg
it still lurches around, not uncontrollably, but it does move so so winding up the acceleration only makes that worse.

In Mach I limited the max travel speed to 5000mm/s (will have to check on that, may even be 3000mm/s) and acceleration to 1000 something's.

Did I read that right.....5000mm/s ........or is it supposed to be 5000mm/min?. 5000mm/s is 18km/hr!!!!

Craig

894

General Mach Discussion / Re: Manual pulse encoder & mach3

« on: January 16, 2022, 01:56:59 PM »

Hi,
that MPG looks like it has a +A/-A output and a +B/-B output.

measure with a multimeter the output of just one, say +A. I suspect it will only go to 2.5V while the -A will go to -2.5V, and then swap over.
This is differential output and I suspect has insufficient voltage to be 'seen' by your BoB.

You may need to build an amplifier that converts the differential to single ended 5V, assuming your BoB is 5V...you don't say.

Craig

895

Mach4 General Discussion / Re: Homing scripts

« on: January 15, 2022, 11:00:50 PM »

Hi,

i was relying on -X and -Y as home to positions or “ref all home”. Does that sound about right?

Yes, that sounds OK.

My first mini-mill never had Limit switches, I had Home switches near the end of each axis but not right at the end. Thus I used the Home switches
and SoftLimits, and did so for seven years, mostly without bother.

My new mill is much bigger, faster and way more powerful so I decided I'd be a fool not to have Limit switches, and so my machine has them AND
separate Home switches, that is nine roller plunger snap action microswitches in all, each one on their own input.

Once upon a time controllers had so few inputs it was necessary to combine a number of switches together on one input.....but why now? My ESS has 51 IO's,
so why not use them?. It means that Mach is NEVER confused about what is a Limit and what is a Home. If the X++ limit activates then Mach knows absolutely
to disallow any jog in the '+' direction but will allow jogging in the '-' direction, no questions, if or buts, or guessing, Mach knows.

My procedure is:
1) Fire up the machine
2) <Ref All>
3) <Enable SoftLimits>

So I still have soft limits, they are set up to be 2mm 'inside' the actual Limit switches, and the Limit switches are 2mm 'inside' the physical hardstop.
The Home switches are 4mm 'inside' the Limit switches.

If a physical Limit switch is activated the machine Estops, as it supposed to, but an Estop results in a loss of reference and so you have to touch off to
your job, if possible, before restarting the job, a PITA. That's why I still use SoftLimits, because Mach will prevent you from going out-of-bounds WITHOUT
losing reference. Should SoftLimits fail for any reason or Mach becomes confused about them then the actual physical limit switches are still there, but with any
sort of luck never actually triggered. In fact every once and a while I deliberately turn SoftLimits off just to test the Limit switches.

Craig

896

Mach4 General Discussion / Re: Key command stop working after running laser gCode

« on: January 15, 2022, 08:07:53 PM »

Hi,
just as a double check make sure the file has genuinely completed. its not impossible for the Gcode file to be still active and therefore have control of the trajectory planner
despite all motion having been completed. Try using <Stop> or even <DisableMach> followed by <EnableMach> after the file has completed.

Another possibility is that the <KeyboardEnable> button may have been triggered during the Gcode file. Try operating the <KeybardEnable> button. Does it make any difference?

Craig

897

Mach4 General Discussion / Re: Glitch on X movements

« on: January 15, 2022, 07:31:07 PM »

Hi,
 its Sunday morning here so I thought I'd make a couple of PCB's, these are ones that I make reasonably often and so like to have one or two in stock if a customer
enquires.

They are surface mount in the main so there are not a lot of through holes, see pics. The drill file takes 1min8sec to drill the twenty-thirty holes or so. The mill file takes 1min24sec
to mill the outline and the four 4.25mm holes.

The top etch file take 46min to run and the bottom etch file 18min.

I could run them faster....but I'm not in that much of a hurry......after all what else would I do....go to church???

Craig

898

Mach4 General Discussion / Re: Homing scripts

« on: January 15, 2022, 07:23:53 PM »

Hi,
I understand....but you have a faulty procedure. SoftLimits ONLY work and make any sens AFTER the machine is Homed or Referenced.

For instance lets say your machine has Home switches such that the machine coordinate zero, ie Home is 50mm from the left hand side and 50mm up from the bottom.
If your machine has travel dimensions of 1200mm x 2400mm then your SoftLimits would be:

X++ 1150mm
X--  50mm
Y++ 2350mm
Y--  50mm

The SoftLimits describe the travel boundaries of your machine but are REFENENCED to your Home location.

When you first turn on Mach it has no idea where it is. Lets say the machine has been parked roughly in the centre of the table, thus when you turn on and engage SoftLimits then
the machine could travel 1150mm to the right...from the centre of the table.....a F..UP!!!

The correct procedure is turn on the machine...then <Ref All>, then <Enable SoftLimits>.

In order for SoftLimits to do you any good you must have Home switches or some other means of repeatably and exactly referencing your machine to Home EVERY startup.

Craig

899

Mach4 General Discussion / Re: Glitch on X movements

« on: January 15, 2022, 06:13:47 PM »

Hi,

The servo trips out because of the load it comes under while trying to move at lightning speed. The issue is, it should not be trying to move at those speeds in the first place.

OK, you have some issues there. As I posted earlier current is proportional to torque and that is proportional to acceleration.

I use 750W Delta servos, and this is broadly How I set them up.  I know the rated torque of my servos, its published in the manual.  Additionally I have done a detailed calculation
of the total momentum of each axis, the Y axis being the heaviest I'll start there. My servos can accelerate the Y axis including a reasonable estimate of the weight of the
workpiece, vice and jigs, at 2.7m.s^-2. Note this is just rated torque, and therefore rated current. The peak current ( equivalently peak torque) is three times that.
I have tested my machine at that acceleration and it works fine with no overloads but it lurches around something chronic and scares the hell out of me.

What I have done is left the servos programmed that way, namely max acceleration (cont. torque)is at 2500mm.s^-2, and the max current at 300% of rated current. So my servos are tuned to
their safe maximum.

In Mach4 however I have detuned them to what I want. For instance I've set the maxium speed of the servos (in the drive) to 5000 rpm rather than their rated max of 3000rpm. This means I can have g0 rapids
of 25m.^-1.....but this is scary fast....and so while I can have it I don't really want it. In Machs Motor tuning page I have set the max speed to 12.5m.s^-1, it's fast enough.
High acceleration is desirable for good toolpath following, but in turn demands more current in the servos and requires greater dynamic stiffness of your machine....so there is a balance to be struck.
I've settled on (in Machs Motor Tuning page) a max acceleration of 1500mm.s^-2.

Note that my Y axis is 115kg of cast iron and I allow a workpiece/vice/jig mass of 35kg for an axis weight of 150kg. It accelerates at 0.15g EASY......and I could have it do much more....but it makes me
sweat just watching it!

The basic idea is to set the servo at its reasonable maximum that does not cause faults and then use Machs Motor Tuning page to select those parameter WITHIN the servos capacity.

Thus if you set Machs max velocity at 12.5 m.s^-1 the machine should never exceed 12.5m.s^-1 EVEN if the servo drive is programmed to be able to go 25m.s^-1.
Likewise I've set Machs max accel to 1500mm.s^-2 despite the servos being capable of 2700mm.s^-2 at rated current and 7500mm.s^-2 at max current.

I have a separate fault signal from each servo, and an on-screen LED, so I can identify which of the servos has faulted. If any one of them faults the machine stops, but I can see which servo it is.
I haven't had a servo trip out in the six months since I finished the machine...they are brilliant.

Craig

900

Mach4 General Discussion / Re: Glitch on X movements

« on: January 15, 2022, 04:53:24 PM »

Hi,

I have rapid (G0) moves on Mach 4 set to 10%, G53 moves move at 10%. These random X moves (that are meant to be G1 moves) will happen at 100% rapid. If I have rapid on Mach4 set any higher than 10% and these X movements occur, it will trip the current overload on the servos and halt all movements but the gcode will still be running on Mach4.

That's a fault right there. If a servo, any servo, trips out over current, over voltage, following error or what ever then the machine must stop. The servo will certainly stop...and signal the error.
Your Mach4 installation should be monitoring the HLFB fault signal and Estop ALL servos if any one servo trips out. I take it you do not have any fault monitoring? That's a disaster waiting to happen.

Next issue is why the X axis is tripping out? Is the X axis much heavier than the others? In a servo, current is linearly proportional to torque and torque is linearly proportional to acceleration.
Do you have the X axis acceleration set (in the drive OR Mach) higher than the other axes? Have you set (in the drive) a more restrictive current limit?

Not sure what Fusion has to do with it. I use Fusion but a paid subsricption...I don't like paying much, but you do get what you pay for and 'bang for your buck' Fusion can't be beaten for value
for money in my opinion. I use Fusion to design the circuit and then export the files to EAGLE, because EAGLE has a UserLanguageProgram called PCB_to_Gcode that will generate Gcode files
for isolation routing, drill files and mill files. Note that the drill files have a syntax that works with Mach3, which was a bit slack as to what kind of code it would accept, whereas Mach4 is a bit stricter.
The code needs to be edited slightly to work on a Mach4 machine, and I use to do it by hand, but I have written a macro which takes the original (Mach3 compliant) drill file and make a new file
which is Mach4 compliant.

I will post the macro if you want it.

The point is that EAGLE has no BS restrictions over rapids....ie the Gcode produced by 'pcb-gcode' has NO restrictions

Craig