Messages

7091

General Mach Discussion / Re: Motor tuning question..

« on: March 24, 2017, 10:11:46 PM »

Hi,
provided there is not some mechanical fault or slippage then your driver is set incorrectly.

Can you post the manual? How about rechecking your microstepping settings.

Try setting for zero microsteps, ie 200 pulses per revolution and set your steps per unit to 200 times 5.08=1016 and try it out.

Craig

7092

Mach4 General Discussion / Re: Mach 4 in Windows 10 needs Windows 8 Compatibility Mode

« on: March 24, 2017, 02:08:14 AM »

Hi Ray,
I have found that if Mach does not shut down properly then it will fail to restart. Often times it is not obvious that a component
of Mach is still running.

I now routinely have the task manager on the task bar so I can determine if a module is hung up, quite a common event when
writing/ debugging LUA code.

I use Windows8 on my laptop for experimenting and coding but Windows7 Embedded on my machine. I've never really encountered
a situation where the OS affects how Mach runs.

Craig

7093

General Mach Discussion / Re: Motor tuning question..

« on: March 24, 2017, 01:57:58 AM »

Hi,
sounds like your accel is to high, start it low, very low and see if that fixes the problem. Then you can experiment to find
the useful maximum for your machine.

You can use the auto-cal function, I don't because I built my machine and I KNOW the parameters and can calculate the
steps per EXACTLY. The auto-cal function is for people who don't know their machine and can't be bothered to find out
and/or get confused over basic arithmetic. You decide which camp your in.

Work your axis backwards and forwards using MDI, going a useful distance each time. Set x=0 then go to x=4in and the back to x=0.
G0 X0
G0 X4
G0 X0
It should go back to the exact starting point. If it doesn't no setting or autocalibration is going to do you any good.

The numbers on the motor tuning screen are:
Step per unit, as discussed above should be 8128
Velocity in/min, recommended less than 98in/min, say 30in/min for a conservative starting point.
Acceleration in/sec/sec, recommended less than 9.8 in/sec/sec, say 3in/sec/sec for a conservative starting point.
G's, this is a display only and tells you the 'G force' corresponding to your acceleration setting above. For hobby machines
0.01 to 0.1 are common, high speed production machines can go upwards of 10.
The next two parameters are the pulse length presented to the motor drive by Mach3. My drivers are good quality Japanese ones
and the specs say 1.25us is enuf. If you have crappy ones 5-10 us might be better. If the pulse is to short the driver might miss it
altogether. Note that when you make alterations on the tuning page you have to 'save before exit' or the changes will not be implemented.

The trick to getting this stuff to work is not to change everything at once, change one item and establish what effect it has. If you can
understand each effect then you are well placed to find the right balance of parameters/settings.

Craig

7094

General Mach Discussion / Re: Motor tuning question..

« on: March 23, 2017, 02:20:56 AM »

Hi,
your calculation is correct, the explanation is a bit wonky....

Your ball screw 1605 is indeed 5mm pitch, ie it moves 5mm per revolution.

1 inch= 25.40mm therefore the screw has to rotate 25.4/5 =5.08 revolutions to move 1 inch. It takes 200 fullsteps or 1600 1/8
microsteps  for the motor to turn one revolution. So your microsteps per inch is 1600 times 5.08 =8128. Set your steps per unit
in Mach3 to 8128 and leave it that way. If you pulse the motor 8128 times the axis should move 1 inch, if it doesn't then the driver
and or motor is missing steps. Fix it.

Make sure your native units are inches, Config/Select Native Units....set to inches and leave it that way. If you need to run a job in
mm's use G20/G21, DON'T mess around with native units.

When your motors move do they move smoothly? What sort of sound do they make, if its in anyway rough it may indicate that the motor
is missing steps. If I understand your description of the fault you first called G0 X1 and it actually moved 0.1 inch. Later you called another
G0 X1 and it moved 0.189 inch. Is this correct? If so that means its not a screwup so much as the motor not be able to pace the instructions
given to it.

In the first instance set the motor tuning slow and the acceleration even slower. Dave often recommends the acceleration be about 10% of
the speed. Try setting the speed to 20 ipm to start with.

Stepper motors exhibit GREAT torque at low speeds, in fact they blow most servos into the weeds at slow speeds, but they can't 'pull the
skin off a rice pudding' at speed. As a start don't expect your steppers to go faster than 500rpm. With 5mm pitch screws that means about
2500mm/min or 98 in/min.

Try settings around these values and let us know how you get on.

Craig

7095

General Mach Discussion / Re: Harbor Freight Mini Mill Relay Spindle Motor

« on: March 22, 2017, 02:14:00 PM »

Hi,
should be written on the motor or at least in the docs that come with the machine.

Craig

7096

General Mach Discussion / Re: Harbor Freight Mini Mill Relay Spindle Motor

« on: March 22, 2017, 11:14:01 AM »

Hi,
I'm guessing you want Mach to turn a relay on and off and the relay turn the spindle on and off?

Mach doesn't have a voltage per se....but the BOB does. Many BOB's are 5v so it could turn a 5V coil relay on and off.
Note also that most BOBs have fairly limited current output, commonly 20mA or less. Your 5V relay will have to be
pretty small and therefore the output contacts may not last long when switching spindle current.

To improve that situation you can use a small 5V relay to control a bigger relay or contactor. Another way is to use a transistor
with the base controlled by the BOB but the collector/emitter circuit controlling a much larger relay than the BOB could handle
on its own.

Craig

7097

General Mach Discussion / Re: Homing

« on: March 22, 2017, 11:03:08 AM »

Hi,
yes you can. The only thing that won't work are soft-limits. They are in machine co-ords and without being homed the
machine co-ords are undetermined.

Craig

7098

General Mach Discussion / Re: Having Issues With MACH3 and new Mill

« on: March 22, 2017, 02:48:50 AM »

Hi,
why bother with the joystick for the moment. Just use the arrow keys and the jog fly-out until you get familiar with it.

Craig

7099

General Mach Discussion / Re: New to mach3

« on: March 22, 2017, 02:44:00 AM »

Hi,
another great way to make usable Gcode and see how a program works is to use the Wizards  that ship with Mach3.
Try some of the pocketing ones...they generate code that you can run and simple enuf to work out how the Gcode works.

Craig

7100

General Mach Discussion / Re: Oval holes

« on: March 22, 2017, 02:39:30 AM »

Hi,
what units do you use?

Mark the current location of the torch. Zero X, move X some reasonable distance, say 200mm or 8in in the X axis only
G0 X8.

Now move it back
G0 X0.

If it does not return to the same position the fix that, no useful work can be done otherwise. Once you are happy that X is moving
the nominated distance do the same thing with the Y axis.
If you wish to cut an 8 inch circle then the X axis must be able to travel 8 inch, not 7.5 or 8.5 but 8. Likewise Y must be able to move
8 inch on command otherwise the circle will not be round.
Fix each axis independently to be accurate first then cutting circles is a doddle.

Craig