Messages

6351

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

« on: October 27, 2010, 05:40:29 AM »

Something lasers are pretty good at is ablating inks and dyes which is why they are often used for tattoo removals. They are also pretty good at removing the dye layer from anodized alluminium and here is an example.
It's only a scrap piece of material which I had kept to be used on another project but I thought I would give this a try and as it happens it turned out reasonably well, I think.

Tweakie.

6352

General Mach Discussion / Re: Pulling Pins High

« on: October 26, 2010, 12:57:25 PM »

I think Brian has his problem sorted now but for those that follow pulling pins high to +5Volts, with a high value resistor 10K or so helps the following logic (and Mach) see the transition, from high to low, when the pin is taken low by a probe or other device – this arrangement is configured within Mach as ‘active low’. Pins could quite equally be pulled low (10K or so to GND) and this arrangement would then be configured within Mach as ‘active high’.
Once upon a time the output from all logic gates was either high or low and a transition was always obvious but then along came tri-state logic which could be either high, low or high impedance (open circuit) which enabled the inputs and outputs of many devices to be physically connected to the same bus and with the use of enable signals communicate to each other without loading those that were just waiting their turn.
Generally the manufacturers of the controllers, breakout boards etc. fit the necessary resistors to the inputs as standard and some even provide the option for pulling high or low as required. As always, their recommendations / instructions should be followed in preference to anything I have mentioned here.

Tweakie.

6353

General Mach Discussion / Re: CD Rom Stepper motor settings or recommendations?

« on: October 26, 2010, 11:32:52 AM »

Has anyone had success driving the 4 wire motors using Mach3?

Hi Mike,

Welcome to the forum.

I think all my steppers are the 4 wire bipolar type (but not out of CD Roms  ).

Tweakie.

6354

General Mach Discussion / Re: Using Mach 3 Pulsing Engine

« on: October 26, 2010, 06:42:12 AM »

I suppose the question is why and for what purpose do you want to use it ?

Tweakie.

6355

FAQs / Re: Losing steps or something?

« on: October 26, 2010, 05:10:21 AM »

I removed the temporary earth strap, but there is still continuity from the Cap to chassis.  I don't know where. 

Just an observation but I think you should pursue this.

Tweakie.

6356

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

« on: October 25, 2010, 07:29:47 AM »

Thanks Jeff, good call. 

Tweakie.

6357

Promote and discuss your product / Re: Mach3 as 3d printer software

« on: October 25, 2010, 03:30:05 AM »

Mach needs most of your computer resource to provide the correct timing etc.
Just a thought, but...... Using an external timing device such as the "Smooth Stepper" may free-up sufficient Mach resource to allow your RS232 communication.

Tweakie.

6358

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

« on: October 24, 2010, 11:50:31 AM »

Thanks, but I think I am a few years behind 

I wondered if the color of the paint used would make any difference to the way the laser performed - answer no.
Surface mount is definitely preferable for this process - now where did I put that etching tank ?.

Tweakie.

6359

General Mach Discussion / Re: Axis Drivers shows error on movement of cursor

« on: October 23, 2010, 11:08:59 AM »

Sidhi,

I think we are going to need a bit more information here about your problem.

What drivers are you using ?
Was it working correctly before this ?

Tweakie.

6360

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

« on: October 22, 2010, 12:39:48 PM »

A few people have asked me if my laser could be used to make printed circuit boards and my answer has always been no. The problem is that copper is such a good reflector at the CO2 wavelength of 10600nm that possibly a kilowatt or more of power (certainly more than I have) would be necessary to vaporize the copper and then it would almost certainly vaporize the glass board underneath as well.
Like all things there is always more than one way of doing everything so as an alternative approach, and being a slack day, I tried this;

The copper clad glass board was sprayed with a rattle can car spray paint then, when dry, the required pattern was laser etched (paint removed) using the Mach3 Impact/Laser plugin. I didn’t quite get this one aligned correctly horizontally but it proves the point that as a system it will work. The car spray paint is resistant to the ferric chloride pcb etchant so all I need to do now is chemically etch away the unwanted copper, drill the holes and clean off the remaining paint. It only took a few minutes to produce this, certainly less time than it will take to etch.

I think this system would be more suited to surface mount rather than through hole because there is no X – Y GCode a drilling file cannot be easily produced and drilling by hand is a real pain when you have a CNC machine sitting idle.

I doubt that this application had been envisaged when the Mach3 Impact/Laser plugin was written. 

Tweakie.