Messages

2061

Mach4 General Discussion / Re: Input/Output PIN Mapping not being saved

« on: September 07, 2019, 02:41:35 PM »

Hi,
I'm not familiar with the UC300 but rather I have an ESS, but I imagine they are broadly similar.

With the ESS the ports an pins are assigned in the ESS plugin, not Machs Control plugin at all.

My guess then there is a fault with the UC300 plugin not saving its values when shutting down. It may
be you need to pose the question on the CNCDrive forum.

Craig

2062

General Mach Discussion / Re: Linear axis error compensation

« on: September 07, 2019, 02:29:52 PM »

Hi,
there is a formula correction that you can use in Mach3. It requires that you can match a mathmatic equation to
the graph. I have attached an example where I assumed that the Z axis required an additional 0.01x²
be added to Z. The formula is applied in  a somewhat hit and miss fashion and was never hugely successful.
The biggest problem was that if Mach calculated a correction it would apply it but that would require your Z axis to move
a small amount (the correction) but Mach would apply it and assume that the Z axis were able to move that small amount
instantly. Steppers motors have a definite maximum acceleration beyond which they stall, and stall is exactly what they do
unless the correction is miniscule. To my knowledge no-one has really gotten it to work properly.

There is a new development in Mach4 in the form of a wizard called mcMapSurface. The essential idea is that you probe
the bed or table of your mill (X and Y axes) and record the variance of the height (Z axis). Mach stores those values
and thereafter automatically compensates the Z axis where and whenever the machine is at any particular X,Y location,
no formula required, no tricky Gcode.

Mach3 has no similar feature.

Craig

2063

General Mach Discussion / Re: Biesse Rover 23 Yaskawa conversion to mach 3

« on: September 06, 2019, 07:18:59 PM »

Hi,
Yaskawa is a superb brand.

Mach3 and Mach4 are natively step/direction controllers. That is they produce one signal (direction) to indicate
to the servodrive which direction the servo is to turn and the other (step) is how many steps it should take.
The number or steps to complete one rotation is determined in part by the encoder fitted to the servo and
other settings like 'electronic gear ratio'.

Modern servo drives can operate in a number of different modes.

1) Analogue....a voltage produced by the controller/motion controller is translated into rotational speed (speed mode)
   or a torque (torque mode). Positional feedback (encoder or resolver) is directed to the motion control which 'closes' the position loop.
   Mach3 and Mach4 can do this BUT ONLY with specialized and expensive motion control boards. Servo manufacturers include
   analogue control so that it could be used as a replacement for older equipment. Good performance can be had but it is expensive
   and complicated....unless you have a particular need don't do it.
2)Pulse or other various names like step/direction, CW/CCW, quadrature. This is a virtually industry standard on all modern servo
   drives and is highly applicable to Mach3 and Mach4 with modestly priced step/direction motion control boards or even
   Machs humble parallel port.
3)Bus Mode. There are a number of communication protocols used by servo manufacturers to enact 'distributed motion control'
   Yaskawa is particularly strong in Ethercat. You will hear other names like CANOpen, Profibus, Profinet and various other
   proprietary schemes. Distributed motion control is highly applicable to industrial control situations where tens or hundreds
  of servos and other devices have to work in concert. The reason I mention this mode is because looking at the pictures
  you have posted the big communication cables, one in and one out, could well be Ethercat cables.

You need to establish what control method has been used. It is common for a servo drive to be equipped to operate in all modes
I outlined above. So despite your machine being wired/configured for Ethercat currently you could re-program the drives
to be step/direction say.

There is a possibility however that the servo drive can ONLY operate in ONE, usually Bus Mode, in which case your
Ethercat drives CAN ONLY be operated as Ethercat drives.

As a first step determine how your machine is controlled currently. Then you need to determine if it could be configured
to operate in step/direction mode.

Craig

2064

Mach4 General Discussion / Re: Does anyone have a "Firmware" (post processor) file for Simplify3D to Mach4?

« on: September 06, 2019, 02:50:13 PM »

Hi poppabear,
if you have a post that produces good Gcode for Mach3 then it should work for Mach4 also.

I have encountered only one instance where code that runs on Mach3 fails under Mach4. Even then its
because Mach4 sticks more closely to ANSI Gcode.

Craig

2065

Mach4 General Discussion / Re: Mach4 & Neuron THC

« on: September 02, 2019, 01:08:33 AM »

Hi,
THC is normally a feature offered by the motion controller as it is required to  operate in realtime.
At this time the Hicon Integra and the ESS are the only Mach4 controllers that offer realtime THC.

What motion controller are you using?

In recent months NFS has released script based THC, which while not nearly as responsive as realtime,
its still pretty good. If you open and run the Mach4 Plasma profile you will see it in all its glory. Enjoy.

Be aware of the difference between the two (realtime vs script) solutions....is not trivial.



Craig

2066

Mach3 and G-Rex / Re: RNR Motion Card English Manual

« on: September 01, 2019, 09:05:06 PM »

Hi,
a manual in any language would be  a start!

Craig

2067

Brains Development / Re: is there a way to access puls counts of axes from within brains

« on: September 01, 2019, 09:03:49 PM »

Hi,

I want use the one of MACH3
thats why I am asking if it is posible to access
step pulses from within Brains

No, it is not possible.

first of all I wont use MODBUS RTU
I want use MODBUS TCP

RTU/TCP matters not, Modbus is serial and therefore cannot transmit pulses simeltaneously.

second I want make my own controller in order to earn money

If you wish to make money then Mach4 is going to be future....Mach3 is slowly fading away.

Craig

2068

General Mach Discussion / Re: Motor tuning, please take it easy on me I'm new to this :)

« on: August 31, 2019, 06:21:13 AM »

Hi,
as a matter of comparison the servo that I ordered today has a rated torque of 1.27Nm and a rated speed of 3000rpm.

If this were fitted to your machine through the same 3:1 reduction I am proposing then the calculation is something
like this:

max speed is 3000/3 x16=16000 mm/min
torque at the leadscrew is 3x 1.27=3.81Nm so the thrust of the axis is 3.81/7.5 x2.94=1.49kN

So a servo equipped machine is about 2-3 times faster but about half the static thrust. With a servo however a short term
overload does not cause a stall as it would with a stepper, the servo just 'digs in'. The overload torque of my new
servo is 3.8Nm so its short term thrust at 16000mm/min is 4.48kN, ie about the same as your stepper but at nearly
three times the speed. Additionally my servo gives has an ultimate resolution of about 0.2 arc min or on a 3:1 reduction
16mm pitch leadscrew a linear resolution of 0.05um!!!

That sort of performance doesn't come cheaply but this calculation shows just how superior servos are in practice and why
they dominate in pro equipment.

Craig

2069

General Mach Discussion / Re: Motor tuning, please take it easy on me I'm new to this :)

« on: August 31, 2019, 05:58:34 AM »

Hi.
if you follow the calculation so far try imagining this:

Desired theoretical max top speed=6000mm/min. Therefore the leadscrew must rotate at 6000/16=375 rpm.
If you had a 3:1 belt reduction the stepper rpm would be 375x3=1125rpm. The low inductance steppers are
such that you will retain approx. 50% of holding torque at 1125 rpm so the available torque from the stepper
at 1125 rpm we estimate to be 0.5x7.5=3.75Nm. With a 3:1 reduction the torque at the leadscrew is3x3.75=11.25Nm.
The resultant thrust as a result of mechanical advantage of the leadscrew, indentical to my previous post, is
2.94 x11.25/7.5=4.41kN or a little over 400kg(force).

Allowing 50% for acceleration that still allows 200kg(force) for cutting forces at 6000mm/min.

As you can see using a belt or gear reduction would allow you to exploit the full potential of your new steppers
and still go as quick as you dare.

Craig

2070

General Mach Discussion / Re: Motor tuning, please take it easy on me I'm new to this :)

« on: August 31, 2019, 05:34:26 AM »

Hi,
if you plan on hooking your new steppers direct to the leadscrews then this is the calculation:

Leadscrew, 16mm diameter, 16mm pitch.
The radius of action (where the ball contacts the groove) will be a little less than the radius of the leadcsrew, say 7mm.
The stall torque of the stepper is 7.5Nm or 0.75kg(force) at 1m which is equivalent to 0.75 X1000/7=107 kg(force)
at the radius of action. The circumference of the circle described by a radius of 7mm is 2x 3.141x7=44mm. If the leadscrew
rotates one turn the axis will advance 16mm. The mechanical advantage of the leadscrew is 44/16=2.75.

Thus the stall thrust of a 7.5Nm stepper on a direct coupled 16mm diameter screw of 16mm pitch excluding frictional losses
will be 107x2.75=294kg(force) or 2.94kN. Not too shabby.

Of course if you had a belt or gear reduction the stall thrust would go up by the reduction ratio and given that these steppers
are likely to be way WAY WAY quicker it would still not count against your ultimate top speed.

Remember that stall thrust is a somewhat slanted or unusual measure of a machines thrust.

Its more realistic to assume that approximately half of the available torque (equivalent to thrust) is used to accelerate the
axes and mass of the workpiece/gantry or whatever and the other half be available to supply the cutting forces required.
A detailed calculation would require much more data on the kinematics of the machine and a much more thorough knowledge
of the cutting forces, the sort of thing professional mechanical engineers thrive on. Its dubious that as hobbyists we need that
sort of detail. If however you were designing and building a $100,000 plus machine for production work you want/absolutely
need to know before you start....and after all mechanical engineers want a job too!

Craig