Messages

351

General Mach Discussion / Re: Physical buttons for plasma

« on: January 19, 2016, 10:44:38 AM »

Oh ... Water table... Is the shed heated (thought I saw the word portacabin somewhere...not sure of the chances of freezing in an unheated shed in scotland)... Also if it's not being used much, consider corrosion (add inhibitor) and bacteria (add a biocide), could always design it to take a water table later if your material throughput justifies it.

352

General Mach Discussion / Re: Physical buttons for plasma

« on: January 19, 2016, 07:48:35 AM »

Are you doing stainless?  If so, I thought a water table was beneficial to avoid blackened edges (so is the use of nitrogen I think it is).

Is it a workplace (as classified by hsawa 1974....)... In that case you would need to consider hsg 258... (Search hsg 258 PDF and you can download the guide for free).

A downdraft chute will also work ... But not on stainless edge quality or blackening (think the grade of SS may be an issue)

Not done SS myself, just read titbits

353

General Mach Discussion / Re: Physical buttons for plasma

« on: January 17, 2016, 03:06:28 PM »

Thanks for the update, I for one will be very interested to know how it works on thin and thick stuff (high and low cutting speed)

354

General Mach Discussion / Re: Probably simple but...(G-Code help)

« on: January 11, 2016, 03:49:37 PM »

Thanks, where is the list of #vars??  Can you toggle other things too like OEMbuttons and LED's etc?

Rob

355

General Mach Discussion / Re: Probably simple but...(G-Code help)

« on: January 11, 2016, 03:28:35 PM »

Apart from my little oddity with the G04, I need a little help with control logic - brains etc, here's what it needs...

The variable #15239 / 1239 is set to 1 or 0 by G-code in the probe subroutine, this variable is monitored by a brain which activates/deactivates output2 (extends or retracts the probe)

This works perfectly UNLESS g-code is loading or you do a path re-gen and it runs the code again as it does when loading - this has the effect of slapping the probe up and down multiple times as it reads the subroutine at every call.

So I am looking for a smart way to block operation when its parsing code.

I have tried to use the other output and the variable AND'ed together in the brain, which works BUT not when i do a dry run or drill holes with the torch as output 2 controls my extract fan and that is off when dry running or drilling so that idea fails.

Is there a smart way to do this please???

why do you need to use a brain.... why not an M-code to trigger the output directly?

356

General Mach Discussion / Re: Probably simple but...(G-Code help)

« on: January 11, 2016, 09:08:41 AM »

The problem with plasma cutters and torch height control, is the THCUP and THCDN commands shunt the z up and down at the maximum z axis velocity * THC Correction Speed (%) [DRO25]

The best (neatest) button / LED / DRO guide or table I found is this one:

https://www.google.co.uk/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&cad=rja&uact=8&ved=0ahUKEwiY3Of29aHKAhVH7w4KHQhpCIUQFggdMAA&url=https%3A%2F%2Fwww.machsupport.com%2Fforum%2Findex.php%3Faction%3Ddlattach%3Btopic%3D19482.0%3Battach%3D27839&usg=AFQjCNGJn1E7RpKyfyjY7STvwaxPFsA6ng

(hope the link works).

357

General Mach Discussion / Re: Probably simple but...(G-Code help)

« on: January 11, 2016, 08:10:48 AM »

You are using G28.1  
G28 is slightly different.

G28 I believe goes back to the home position (which are the home offset co-ordinates you enter into the boxes)

G28.1 goes in the direction of the home position and and zero's the axis.  (zero is not quite right as it inputs the offset once tripping the home switch ... but you get the idea).

So... G28 just goes there, (slows down at the "slow zone" and moves at the jog speed) ...
G28.1 finds the home position using the home switches (at the jog speed).


Official definition here:
G28 & G30 Return to Home

A home position is defined (by parameters 5161-5166). The parameter values are in terms of the absolute coordinate system, but are in unspecified length units.

To return to home position by way of the programmed position, program
G28 X~ Y~ Z~ A~ B~ C~ (or use G30). All axis words are optional. The path is made by a traverse move from the current position to the programmed position, followed by a traverse move to the home position. If no axis words are programmed, the intermediate point is the current point, so only one move is made.


G28.1 Reference Axis
Program G28.1 X~ Y~ Z~ A~ B~ C~ to reference the given axes. The axes will move at the current feed rate towards the home switch(es), as defined by the Configuration. When the absolute machine coordinate reaches the value given by an axis word then the feed rate is set to that defined by Configure>Config Referencing. Provided the current absolute position is approximately correct, then this will give a soft stop onto the reference switch(es).

358

General Mach Discussion / Re: Probably simple but...(G-Code help)

« on: January 11, 2016, 07:26:15 AM »

the g28.1 home co-ords are set by the lower highlighted box on the left hand side and the approach speed is done by the boxes on the right hand size main table.

Go >>> config (top line) >>> Homing & Limits

359

General Mach Discussion / Re: Probably simple but...(G-Code help)

« on: January 11, 2016, 05:51:35 AM »

Do you need the double incremental and absolute change?

May not require it.  As the DRO numbers dont change.

With g28.1 why are you setting the DRO with g92?
Curiosity not expert here.
As it will input the numbers shown on the config homing page (do a screenshot tonight, but from memory its the bottom lhd boxes)

You should not need the first g4, and the second g4 probably required more than p0... Like p1

Again I'm new at this and no expert but always learning

360

General Mach Discussion / Re: Probably simple but...(G-Code help)

« on: January 11, 2016, 02:40:43 AM »

Violent implies acceleration is too high as it should accelerate smoothly and quickly up to maximum velocity and back down, over a short distance it should never reach maximum velocity.

Suggestions... Half whatever the present acceleration is and rerun the code with g0 and without the pause, what does it run like (quick check and as your experimenting).

What acceleration and velocity do you have for each axis out of curiosity, plus steps per mm (or inch).