Messages

7501

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.

7502

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.

7503

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.

7504

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

« on: June 27, 2009, 09:12:19 AM »

Excellent work. 

Tweakie.

7505

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.

7506

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.

7507

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.

7508

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

« on: June 26, 2009, 08:53:11 AM »

Chris,

You need to be wearing protective goggles. Do not look at the reflected beam without them.
If you use a benchtop PSU then providing 2 to 3 volts to the laser control board the laser will emit a LED beam (without lasing) which is easy to focus. Then turn up the wick to 5 Volts. (a DC power source would be better).

Tweakie.

7509

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

« on: June 26, 2009, 07:37:48 AM »

Just a word of consolation - my laser won't melt butter either.
However if somebody ever produced black butter the laser would surely cut it !.

Tweakie.

btw. These low power lasers have to be focussed to a dot the size of a pin point to have any affect on anything - do you have a good lens ?.

7510

Share Your GCode / Re: CNC "rackmount" pizza box server plans for MiniITX mobo, PSU and dual 3.5" H

« on: June 26, 2009, 07:22:31 AM »

Wow !

Tweakie.