Messages

4341

Show"N"Tell ( Your Machines) / Re: The Laser Project.

« on: August 24, 2012, 07:30:04 AM »

Eventually my laser has started to show some erratic behaviour by failing to trigger properly at low current settings and it is now evident that it is time to replace the tube.
The original has done some sterling service over the last few years (imported from the USA in March 2007) but they don’t last forever and must always be regarded as expendable components.

Also as always, nothing is ever simple and I have not been able to easily obtain a ‘size for size’ replacement so some modifications are going to be required to accommodate a longer length of tube.

The standard 30/40 Watt Chinese laser tube is approx. 700mm overall length and offering one up to the existing enclosure shows that I will need to construct bit of an extension to enclose the high voltage end.

Something I learnt a few years back – no CNC project is ever finished it always remains an ongoing adventure.  

Tweakie.

4342

General Mach Discussion / Re: quilting or embroidery machine

« on: August 22, 2012, 12:36:49 PM »

Hi Larry,

I am pleased this has created inspiration - now I am looking forward to reading about your new developments. 

Tweakie.

4343

General Mach Discussion / Re: quilting or embroidery machine

« on: August 22, 2012, 10:40:03 AM »

Hi John,

If connecting PC to machine via the Parallel Port there are only 5 available inputs per port so a second parallel card would be required or perhaps an external motion controller may be a better proposition.
Mach3 is intended to be fully customizable and I see no major problems with implementing most of the functions from buttons but I think you would also need a tracker ball (similar function to mouse) for some of the operations.
Ideally you would use a ‘touch screen’ display - creating positioning and labeling any new buttons as required using one of the various Screen Designer programs freely available. (Many of the button functions you mention are already on the screen, they would just need resizing with new captions etc.).
I am not certain about running the program backwards as I have never used the Reverse Run feature but it may be easier to scroll the program back then use Run From Here.

Tweakie.
 

4344

General Mach Discussion / Re: quilting or embroidery machine

« on: August 22, 2012, 07:21:05 AM »

Hi John,

Once Feed-Hold has been evoked and the machine stops you can jog the axis anywhere you wish. The position is recorded by the DRO's.

When 'Run From Here' is evoked it will return to the position where it left off or the position shown in the current GCode line you have selected. (Jogging the axis will not loose position).

Tweakie.

4345

General Mach Discussion / Re: quilting or embroidery machine

« on: August 22, 2012, 02:08:28 AM »

As long as position is not lost (the interrupt is a Feed-Hold) then the GCode can be scrolled back to any previous point then the 'Run From Here' feature used (setting a suitable Rapid Height clearance) making the necessary Preperational Move and then the program re-commenced using Cycle Start.

Tweakie.

4346

General Mach Discussion / Re: Decimal precision.

« on: August 22, 2012, 01:31:49 AM »

 

Tweakie.

4347

General Mach Discussion / Re: Decimal precision.

« on: August 21, 2012, 12:15:55 PM »

Ah woods nae hae tauld ye anyway. 

Tweakie the sassenach.

4348

General Mach Discussion / Decimal precision.

« on: August 21, 2012, 07:38:47 AM »

Does anyone have any ideas on how I can convert an existing GCode file which has 4 places of decimal precision to a similar file with just 3 places of precision please ??

It doesn't have to do anything fancy such as rounding, I would be happy to just loose the 4th decimal place.

Don't ask why 

Tweakie.

4349

General Mach Discussion / Re: Touch Off Macro Half Works

« on: August 21, 2012, 03:04:25 AM »

Hi Greg,

Sorry to say this but it sounds to me like your problems are a lot more deeply routed than just the operation of this probing script.

As there is nothing in the probing script which could possibly command any X Axis movement you should perhaps look at your machine setup in general as it is exhibiting signs of being extremely unstable.

It could possibly be with your Mach installation, your PC, the motion controller or even electrical noise pickup on your wiring but you would be wise to investigate and resolve this issue first.

Tweakie.

4350

General Mach Discussion / Re: quilting or embroidery machine

« on: August 21, 2012, 02:27:13 AM »

Hi Larry,

A very theoretical answer…..

Assuming you could find (or create) a point where the thread is under (more or less) constant tension then it would be possible to sense a break using an optical switch. The output of the optical switch (normally open or normally closed, depending on type or how it’s output is biased) could then be fed into a Mach Input (via your 4 port board) and trigger an event in a similar way that a limit switch halts motion.

Yes, you would have to include some form of safety stop feature before hands were placed within the danger zone but you don’t want to loose position so this has to be carefully thought out. A ‘Feed-Hold’ followed by ‘Stop’ will enable position to be maintained but the only real ‘safe condition’ disconnects all power to the machine (loosing any current stepper motor micro-steps on restoration of power). It all depends on the level of safety you consider is required after fully assessing the potential risk to your well being. 

Tweakie.