Messages

3331

Mach4 General Discussion / Re: Mach 4 and ATC

« on: December 29, 2018, 03:36:01 AM »

Hi,

Mach4Hobby/LuaExamples/ToolChanger.....you will find examples. You will almost certainly have to edit/modify the code to suit
your particular machine.

Mach4s strength is its ability to be customized, to accommodate very different toolchangers for instance, but it will require you learn to code
in Lua and using Machs modular structure.

Craig

3332

Mach4 General Discussion / Re: Variable offset in Mach4

« on: December 28, 2018, 06:54:54 PM »

Hi Frank,
I use a software utility called Autoleveller. It is primarily designed for use when isolation routing of circuit boards.

Any variation in Z height due to either machine inaccuracy or PCB blank warp/bow/twist causes a very great loss of quality of the
finished job. Autoleveller causes the PCB blank to be probed at close intervals AND THEN uses that height variation data to modify
the Gcode, in particular introduces small variations in Z to match the bow/warp of the blank. It breaks large linear moves into smaller
moves to apply a varying correction, much like I have suggested your lathe correction program would be required to work.

There are some similarities between Autoleveller and what you want to do.

Autoleveller is open source so you can easily see how they have done it. It is written in Java.

http://www.autoleveller.co.uk/

Craig

3333

General Mach Discussion / Re: maximum work area

« on: December 28, 2018, 06:42:39 PM »

Hi,
I have regularly loaded PCB etch files over 100,000 lines in both Mach3 and Mach4.

Regrettably I managed to lose my Mach3 licence file a few months back and as I use Mach4 now I haven't
been bothered to replace it....ergo I can't load a big file in Mach3 to demonstrate....but certainly when I was still using
Mach3 two years ago I was running files of 100,000 lines.

Craig

3334

General Mach Discussion / Re: maximum work area

« on: December 28, 2018, 12:48:50 PM »

Hi,
you can cause the machine boundaries to be displayed on the toolpath screen if the setting is made in Config/Toolpath per the attached.

The boundaries are the soft limits in Config/Homing-Limits page.

If a Gcode file is loaded which is larger than the boundaries it should still be displayed but the job could not run without going out-of-bounds.

Unless mach3 is licenced (check Help/About to confirm licence status) it will load only 500 lines.


Craig

3335

Mach4 General Discussion / Re: Variable offset in Mach4

« on: December 27, 2018, 11:36:44 PM »

Hi,
yes you could write a correction program. The way I am thinking is that if you run your Gcode file through the
correction program it would rewrite the code with the X axis 'corrected' with a figure (plus or minus) from a table
with vertical ordinate in Z.

As an example, lets say you measure your lathe to get this table:

Z Axis    Correction
0             0
50           0
60            0.005
70            0.006
80            0.01
90            0.01
100          0.012
110          0.01
130          0.009
140          0.008
150          0.005
160          0.004
170          0


With Gcode like this:

G1 X50 Z170
G1 X50 Z160
G1 X50 Z150


would become:
G1 X50 Z170
G1 X50.004 Z160
G1 X50.005 Z150

etc.
The program you write would have to apply the correction. There are a number of points that would require some careful programming.
For instance, let say your machine is at X=50 Z=200 and you wish to take a cut to X=50 Z=75, ie a cylindrical cut of 125mm from Z=200
to Z=75. That could be coded:
G1 X50 Z75.

But the code you would have to run would be:
G1 X50 Z170
G1 X50.004 Z160
G1 X50.005 Z150
G1 X50.008 Z140

etc. That is that one move (G1 X50 Z75) would be required to be split into smaller moves so that a varying correction can be applied.

It would require some serious programming on your behalf. Are you up for it?

Craig

3336

Mach4 General Discussion / Re: PWM mode smoothstepper

« on: December 27, 2018, 11:11:35 PM »

Hi,
On the Configure/Plugins/ESS/Spindle tab check the box for PWM (and PID if you need it and have an index signal to make it work).
Specify port1 pin 14 on the Configure/Plugins/ESS/Output Signals tab.

Craig

3337

VB and the development of wizards / Re: auto soft limits

« on: December 26, 2018, 01:06:26 PM »

Hi,
do you have home switches? Soft limits only work once a machine has been 'homed' or 'referenced' to a particular and repeatable location at the
beginning of each Mach session. That normally means home switches are required.

Craig

3338

General Mach Discussion / Re: Is this a "look ahead" problem?

« on: December 26, 2018, 04:35:31 AM »

Hi,
it sounds more like C(onstant)V(elocity) mode. In CV mode Mach attempts to keep the machine cutting at a constant speed an to do so it
'cheats' a bit by pre-empting corners and so on.  In most circumstances such cheats are perfectly acceptable but in some instances result in poor
toolpath following and poor parts as a result.

You might try ExactStop mode. This will cause Mach to follow the toolpath exactly but more 'stopping/starting/jerking around'. Worth trying to see
what sort of difference it makes.

The setting ig made on Config/General Config page per the attached. You may have to restart Mach to see the effects.

CV mode is a way to (try) overcome finite acceleration of your axes. If you had infinite acceleration then ExactStop and ConstantVelocity modes become the same.
Thus it is a good idea to tune your machine for the maximum reliable (no loss of steps) acceleration your steppers can manage.

Craig

3339

General Mach Discussion / Re: Delta servo and uc 300 5 lpt motion controller.

« on: December 26, 2018, 02:50:36 AM »

Hi,
the same single transistor circuit I posted earlier will work on a UC300 output OR an output of you existing BoB.

Note that it will 'invert' the logic. Thus if the UC300/BoB output is high (5V) then the transistor turns on and it sinks current reducing
the collector voltage to VCE_sat, about 0.2V, ie low.

You will need at least three such circuits to get one servo to work, one for the step, one for direction and one for servo enable.

Craig

3340

General Mach Discussion / Re: Delta servo and uc 300 5 lpt motion controller.

« on: December 25, 2018, 04:28:45 PM »

Hi,
the UC300 is  a 5V TTL device. You would be most unwise to hook it directly to ANY other device that either has onboard a differing
power supply voltage or even requires a signal source of a different voltage.

If, for instance, the Delta servo drive has a input hooked via a resistor to 24V expecting your input device (the UC300) to sink current and
'drag' that 24V down to near zero then there is a high probability that the 24V will damage the TTL output of the UC300.

For this reason you need a buffer or amplifier that adapts the 5V TTL output of the UC300 to the 24V Delta servo drive.

As I posted earlier a simple NPN transistor (or a N channel MOSFET) would be a simple way to do it. You would require one for each
input (1 step plus 1 direction for two servos, (1+1) x 2 =4) and one for each servo enable line, ie another 2 transistors. You may wish to
consider additional circuitry for each of the servo drives to signal the UC300 if a fault occurs with either drive. This could be done
with a resistor and a zener diode. As you can see this dictates that you will have to solder together six transistors, 8 resistors and two
zener diodes at a minimum. If you are not electronically inclined that may rather put you off. I am electronically inclined and trained and so
would happily persue this idea where you may not.

As Gerry has pointed out the UB1 breakout board includes all that circuitry. Exactly why it would not work for a USB connected UC300 is a bit
of a mystery to me. I think it would be worth an email to the manufacturer to ask if that is the case and if there is a modification that would
allow a USB connected to be used. Gerry is clearly impressed with the quality of the UB1 and with Gerry's experience that comes as a high
recommendation.

Craig