Messages

1631

Mach4 General Discussion / Re: Mach4 using PoPendant

« on: March 16, 2020, 05:20:05 PM »

Hi,
I use an indentical process when making circuit boards. Just beware if you change modes.....you'll have a spectacular
f...k up otherwise.

Craig

1632

Mach4 General Discussion / Re: Slow stepper speeds

« on: March 16, 2020, 02:05:04 PM »

Hi,
the feed rate DRO should be an accurate representation of the current actual speed but may not, in fact seldom is, the same
as commanded speed.

If I commanded a g1 of 1000mm/min I would expect that when the axis reaches constant speed, that is after the acceleration phase,
that the feed rate DRO would display anywhere between 950 and 1050 mm/min say.

Craig

1633

Mach4 General Discussion / Re: Mach4 using PoPendant

« on: March 16, 2020, 01:55:20 PM »

Hi,
Mach has only one, and can only have one trajectory planner. If the planner is under control of the Gcode interpreter,
ie running a Gcode job then it will ignore the pendant. Likwise when the trajectory planner is under control of the pendant
then much of Mach is disabled  including the Gcode interpreter.

The best way to stop the Gcode interpreter is <FeedHold> followed by <Stop>. The Gcode interpreter stops but the file does not rewind
nor are the modals lost. If you hit <CycleStart> the job will continue.

The only time you will have trouble with this procedure is if you change any modals when you jog with the pendant...unlikely. If however
you MDI while the Gocde file is paused then it is probable that you will change one or more of the modes and therefore when you
hit <CycleStart> the Gcode job will resume but with the incorrect modes applied with unpredictable results.

The correct procedure under that circumstance is <Run From Here>.

Craig

1634

General Mach Discussion / Re: Error Triggered Only When I close Mach3

« on: March 15, 2020, 02:35:11 PM »

Hi,
I'm only guessing but when Mach shuts down it saves its current position (machine and work coordinates)
and it sounds like it is not doing so thereby causing an error.

Craig

1635

General Mach Discussion / Re: Error Triggered Only When I close Mach3

« on: March 14, 2020, 07:28:43 PM »

Hi,

When I restart I have to Ref. all home each time. Any ideas what would cause this.

That what you're supposed to do. When you first turn on the machine it does not know where it is, unless you direct
it to some repeatable and specific location (home).

Craig

1636

General Mach Discussion / Re: Question on Novum V2 BOB

« on: March 14, 2020, 07:24:47 PM »

Hi,
I believe the current price of a Mach3 license direct from NFS is $175USD.

If you paid $170 for the controller and the license then I'm dubious about the license. An email to NFS Support is in order.

Craig

1637

Mach4 General Discussion / Re: Slow stepper speeds

« on: March 14, 2020, 07:20:42 PM »

Hi Steve,

In Mach3 there was an on screen DRO showing the current instantaneous velocity. Is there an equivalent in Mach4 that I am overlooking?

Yes, there is, see attached.

I think your suggestion is good...to OP: MDI some commands, for instance g0 x300 (assuming mm units here) and observe the feed rate
DRO. Does the DRO show what you believe to be the correct G0 rate?

How about MDIing g1 x200 f300....does the feed rate DRO show 300mm/min. If not, why not?

Craig

1638

Mach4 General Discussion / Re: Slow stepper speeds

« on: March 14, 2020, 05:31:16 PM »

Hi,
the ESS plugin has the ability to assign motors to axes and output pins of the ESS but it has NO motor tuning
features, motor tuning is the sole responsibility of Machs Control plugin.

Craig

1639

General Mach Discussion / Re: New to DIY cnc , Looking for some guidance and advice on first CNC

« on: March 13, 2020, 11:39:50 PM »

Hi,
CNC is a learning curve, no doubt.

I have always maintained that a 'success, or otherwise, of a hobby is gauged by what you have to learn in the process of doing it'.
In this regard CNC has been a great hobby for me, I have had to apply myself to many different facets from design to machining,
and the list of things to learn seems longer now than when I started.

As far a limit switches and home switches go I would commend that you have separate homes and limits, but be aware very few
CNCers agree with me, most combine limits and homes with sometimes un-predictable results.

I prefer mechanical snap action roller plunger microswitches for homes, I find the natural hysteresis distinctly advantageous
in homing routines. Even without Index homing (if you use servos you will be able to explore this further) I achieve 0.02mm
repeatability. It is sufficient, so much so that I have not deemed it necessary to invest the required time and dollars into Index homing.

https://nz.element14.com/honeywell/bzc-2rq18-a2/switch-basic-top-roller-plunger/dp/1525198

Note that home switches are not required to be at the end on an axis, they can be anywhere within the travel of the axis. There
is advantage in having it near the end but comfortably within the very end of travel. With roller plunger switches I mount
the switch parallel to the axis and the roller plunger is activated by an small aluminum (adjustable) ramp attached to the axis.
This means that under no circumstance can an over-running axis damage my switch by excessive over-travel.

I also had small mechanical (small=cheap) switches as limits on my mini-mill. I had not thought out the consequences of an
over-running axis and I managed to wipe some of them out. I removed them in disgust. I always meant to replace them....
but I've just never get around to it. With good home switches I find that Soft Limits are adequate, and I haven't crashed my machine
for several years.

My new build mill will have G0's of up to 25m/min  and 75-100kg axes so I'd bloody well better have, and well thought out,
limit switches or I'm really going to  screw up bigtime.

For limit switches economical proximity sensors are adequate. Hysteresis it not required or even desired with limit switches.
Given the speed and weight of my axes I may have to have  both a limit (extreme) and a 'slow limit' just inboard.
In the event of an overrun the 'slow limit' would operate first and decelerate the axis and then should the extreme limit switch
operate, then Estop.

Don't be over concerned with work offsets just at the moment. The single best thing I ever did to my existing mini-mill was add decent
home switches. THEN and ONLY THEN do Soft Limits make any sense and likewise being able to save work offsets like G54 ONLY
make sense relative to a FIXED and REPEATABLE HOME location, ie home switches. If you fit decent home switches and maintain
good homing discipline when starting a Mach session that confusion will evaporate and you will look on in bemusement as others
struggle to control their machine without disaster striking because either they have no home switches or are ill-disciplined about
using them.

Craig

1640

General Mach Discussion / Re: New to DIY cnc , Looking for some guidance and advice on first CNC

« on: March 13, 2020, 09:01:36 PM »

Hi,
it has recently come to my attention that there may be a better choice of servo than the B2 series Delta I have recommended.
I personally have bought four B2 series Delta's and am EXTEREMLY impressed. I have one 400W example that I bought
to experiment with and fit in place of one of the steppers in my mini mill, and three 750W (one braked) B2's for a new bulid
mill I'm working on.

The B2 series servos have a native 160,000 count per rev encoder. A later model Delta servo, the A2, has a native 1,280,000 count
per rev encoder but more importantly it is 'dual sensing'. Either servo has more encoder resolution than I will EVER need but I am
impressed by dual sensing.

It means that the servo drive monitors the servo mounted encoder as usual but can also monitor a second encoder hooked to the 'load',
like a linear scale for instance, and incorporate it into the positional control loop. They cost only an extra $50 more than I paid for
the B2 series servos. I actually have no need of this extra capability but if I had known that I could have had it for a little extra
I would have bought them.

There is an even later model, the A3 series, which have a 24 bit absolute multi-turn encoder with battery backup. This means that when
the servo is powered up it will recall exactly where it is, both within one revolution but within +- 128 turns of its nominal home
position....no need to 'home'. They are not yet widely available in the Ebay channels I tend to use so would expect to pay a premium
for them that I can't justify.

These features are simply not available in Clearpaths. You are right, Clearpaths are amongst the simplest of modern AC servos to set up
but that ease of setup has cost the flexibility of application that other brands have.

Note also that ALL servo manufacturers tend to have similar features, if one manufacturer introduces market leading
'dual sensing' say, then a few months later they will all have it.

When I got my first B2 series Delta I intended to program the drive by 'button pushing' on the drive itself. It can be done but
is a very tedious and error prone process. In the end I bought a genuine Delta accessory, a programming cable, that then allowed
me to use the Delta supplied PC freeware to program the drive....so much better!. Just wait until you see the plethora of tuning aids
that comes with the software. Highly recommended. Suggest you allow an extra $50 or so in your budget to get a cable, you only
need one to program as many drives as you have....its well worth it.

Craig