Messages

7511

General Mach Discussion / Re: use laser cut on mach3

« on: June 29, 2009, 10:07:26 AM »

As far as safety is concerned there are two points to be observed.
1) Safety goggles with an OD rating for the wavelength of the laser in use must be worn by you and anyone else that may be present.
2) As many materials give off toxic fumes when burned the work area must be well ventilated.

I have not yet figured out how to control the burn marks produced on the surface of the work. Speed of cut has a lot to do with it I think. Possibly reverse one axis to produce a mirror image and then cut from the back of the work ?.

My laser came from Virtual Village, China but I understand that they no longer supply the 150 mW version.

Power supply is a 0 - 30 Volt 2 Amp benchtop PSU with current limiting.

Laser is controlled with Mach3 and I am using vector toolpaths converted to GCode - Z axis is disabled and Z axis DRO scale factor is used to set the dwell time. To turn the laser on and off (between cuts) I am using a shutter controlled by the Z axis direction signal.
This link may be of interest to you:-   http://www.cooperman.talktalk.net/index_files/Page4549.htm

The ebay laser looks good but you may need to add a focusing lens. perhaps you should try and get more details from the supplier.

Nice machine you have there.

Tweakie.

7512

General Mach Discussion / Re: use laser cut on mach3

« on: June 29, 2009, 08:39:25 AM »

You may find some of the information you are seeking in these threads:-

http://www.machsupport.com/forum/index.php/topic,11396.0.html

http://www.machsupport.com/forum/index.php/topic,11732.0.html

Tweakie.

7513

Show"N"Tell ( Your Machines) / Re: BladeRunner

« on: June 28, 2009, 12:42:30 PM »

Like your Flow TX as well.

Tweakie.

7514

Show"N"Tell ( What you have made with your CNC machine.) / Re: My first attempts at laser engraving.

« on: June 28, 2009, 07:06:59 AM »

Hi Chris,

The secondary cable on your laser controller board is for the TTL modulation input, if you choose to use it. The white wire is connected to ground and the blue wire is for the TTL signal (<0.5 Volt=closed and >2 Volt=open) this already incorporates a 'pull up' resistor so pulling the blue wire to ground turns the laser off and open circuit turns the laser on. The spec for the modulation input is TTL levels at a frequency no greater than 15 kHz.

Tweakie.

7515

Show"N"Tell ( What you have made with your CNC machine.) / Re: My first attempts at laser engraving.

« on: June 28, 2009, 05:20:46 AM »

Looks good prices John - are you going to buy a kit of parts then ?.

For me, CNC stuff is not so much about 'spending money on experiments' it's all about acquiring practical knowledge and practical experience. The theory can easily be obtained for free.

Tweakie.

7516

Show"N"Tell ( What you have made with your CNC machine.) / Re: My first attempts at laser engraving.

« on: June 28, 2009, 05:01:54 AM »

Hi Chris,

If, like me, you need to wear spectacles for close up work then the goggle variety of protective eye ware are preferable as you can still wear your spectacles and wear the goggles at the same time.

Tweakie.

7517

Show"N"Tell ( Your Machines) / Re: BladeRunner

« on: June 27, 2009, 09:12:19 AM »

Excellent work. 

Tweakie.

7518

General Mach Discussion / Re: Serial connecting all 6 home and limit switches

« on: June 27, 2009, 04:37:15 AM »

Hi Adam,

There is no reason that this should not be OK but make sure you use screened cable to avoid picking up noise and getting false triggers with the long cable runs you will be making.
Funny thing about energy chains is that you can always squeeze in one more cable but never two. 

Tweakie.

7519

General Mach Discussion / Re: Intermittant pulse frequency. An old school gamer fix that worked for me.

« on: June 27, 2009, 04:29:11 AM »

Hi Eric,

Brilliant solution - thanks for the tip (and download link).

Tweakie.

7520

Show"N"Tell ( What you have made with your CNC machine.) / Re: My first attempts at laser engraving.

« on: June 27, 2009, 04:23:41 AM »

Hi Chris,

You really need to get goggles that have an optical density rated for the wavelength of the laser you are using. Welding goggles may protect your eyes but they are too dark to be of any real practical use.

Tweakie.