Messages

91

General Mach Discussion / Re: Mach3 logic help

« on: September 02, 2016, 07:49:23 AM »

Seem to remember that Hood runs his Chiron around 0.5G - he'll be the best man to advise on real world values.

92

General Mach Discussion / Re: Mach3 logic help

« on: September 02, 2016, 06:58:04 AM »

BTW on a servo machine like my Bridgeport conversion, how is it best to arrive at an acceleration figure?

Like we once discussed for your plasma - ideally, you can never have too much accel. In the real world though, the limits are defined by the power of the motion system and the rigidity/strength of the machine. So, as high as you can get it before stalling/faulting or machine destruction rear their ugly heads.

93

General Mach Discussion / Re: Mach3 logic help

« on: September 02, 2016, 04:48:01 AM »

I am on to something now, as I have been playing with setups today, and here are my current machine setup.

Velocity 6000 mm/s
Accleration 1000/s/s (was set to 300 mm/s/s)

  Throughout the thread you've said your accel was 2000mm/s/s.

If you actually have been using 300mm/s/s then that explains everything you've been seeing. 300mm/s/s is hopelessly low for CV to produce the accuracy you're trying to achieve.

When using CV mode, the accuracy of the actual path, i.e. how close it is to the programmed path, is directly proportional to acceleration. This I'm afraid is true of every machine and every controller on the planet - blame it on the laws of physics.

Acc: 2000mm/s/s goes up to 4000 mm/s/s without problems, but that is insane acceleration.

What's insane about it? 4000mm/s/s is not particularly high for a truly rigid machine. if your machine is capable of 4000mm/s/s then that is what you should be using. The ONLY reason you would turn DOWN accel. is when the jerk your drive system is capable of creating exceeds the rigitity of your machine.

A word about Mach3's CV settings like dist. tolerance etc.

ALL CV settings are there to try to help when a machine's acceleration is not good enough for the job expected of it. i.e. they ALL stop CV from working to its fullest extent one way or another i.e. they all take CV closer and closer towards exact stop. On a machine with accel. good enough for the job expected of it - they should ALL be completely OFF.

Finally a note for Dave. A Lookahead of 1000 is at best nearly always pointless and at worst counter productive. I don't really care about the hair-pin at john o'groats before I've left the car park at land's end. Well unless I'm travelling at the speed of light and my brakes are really crap - then I might.

94

General Mach Discussion / Re: Haas VF1 Conversion

« on: August 13, 2016, 11:58:44 AM »

This makes perfect sense.  I probably made stupid assumption thinking about modbus with coils and registers and then seeing the "bit" in GetInBit.

TBH there's no particular reason that immediately comes to mind why it SHOULDN'T have been written as a boolean function. But tis what tis.

So I think you are saying that I should never have this:
If GetInBit() Then...

But instead, it should be

If GetInBit()=1 Then...

You got it.

But please remember, this is for NON boolean types. If the type IS boolean - please don't write this sort of nonsense:

if someBooleanExpression = false then...

95

Screen designer tips and tutorials / Re: The .set file format

« on: August 13, 2016, 11:41:29 AM »

Thanks again for the help!

No worries.

Would you be able to share any details about it?  Is it something you've made public or will make public?  Just curious.  I'm writing a screen designer as well; not sure how much overlap or similarities we'll have, but I'd be interested in hearing what you've done.

I never finished it to anywhere near releasable. See this thread http://www.machsupport.com/forum/index.php/topic,25574.0.html

As you can see, there was clearly no interest so I moved on to other things.

96

Screen designer tips and tutorials / Re: The .set file format

« on: August 13, 2016, 07:24:54 AM »

You may well have sorted this by now but if not...

AFAIK there is no later doc than the one you have. However many moons ago I reverse engineered the set file format in order to write my own screen designer.

So here you go. If the macro (or gcode) is less than 255 chars then the length byte indicates the length (as you know)

However if the length of the macro is 255 or greater then the length byte should be set to 255 and the following two bytes set to indicate the length. (hi, lo) IIRC.

97

General Mach Discussion / Re: Normally Open VS Normally Closed

« on: August 13, 2016, 05:49:56 AM »

Re: your "if not bug". see your other thread at http://www.machsupport.com/forum/index.php/topic,32497.msg228208.html#msg228208

98

General Mach Discussion / Re: Haas VF1 Conversion

« on: August 13, 2016, 05:49:49 AM »

There is no "if not" bug.

getInBit() and getUserLED() are INTEGER functions which return 0 or 1.

Contrary to (seemingly popular) belief, the integer values 0 and 1 are not 100% equivalent to false and true. (at least not in BASIC).

To use integer expressions correctly in logical contexts they should either be explicitly cast to booleans or perhaps more normally, explicitly compared to the required values. In the second case of course, the comparison itself yields a boolean result, hence no need for casting.

So why (I hear you ask) does getOEMLED() work just fine with "if not"?

Simply because it is not an integer function, it actually IS a boolean function.

The moral of the story? - don't indulge in type abuse - it'll bite you sooner or later.

99

General Mach Discussion / Re: Physical buttons for plasma

« on: April 30, 2016, 07:30:57 AM »

Re: the cable: You could always stick a jack box at the mid point and plug your coiled cable into that - voila - you'd only need 1.5m.

Or - how about using infrared - no cable needed.

100

General Mach Discussion / Re: Physical buttons for plasma

« on: April 28, 2016, 03:39:00 AM »

Ah OK. Your dust/smoke extraction is going to have to be REALLY good then. Don't risk breathing ANY of that sh1t - it's REALLY bad for your health.

Ian