Messages

6891

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

« on: December 16, 2010, 06:08:17 AM »

Thanks Guys.

As a matter of interest, perhaps, the minimum achievable laser spot size is a function of the lens focal length and in my case the minimum spot size is about 0.1mm diameter. However, the photons (or whatever laser particles are called) are more concentrated across the center of this 0.1mm spot in the direction of it's travel (because the centre line of the spot is longer than a chord) and as the burn rate is time related, with a fast scan, a much finer line than 0.1mm can be drawn on an object. In some ways it is a bit like sharpening a pencil except that the faster the laser scan, the finer the burn line that can be achieved (within limits that I have yet to discover).
This is to a certain extent demonstrated in this Aztec calendar as finer detail than 0.1mm can be observed.


Tweakie.

6892

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

« on: December 16, 2010, 05:04:45 AM »

A revisit to the Aztec calendar, as I had some mirror tile left over from another job.

This is laser engraved on the back of the tile and before anybody tells me - yes I know that I forgot to flip the image horizontally so the calendar is backwards 
This was a lot easier to make than it was to photograph - I took about 20 shots before I got one reasonable one. I have only just discovered how hard it is to photograph mirrors. 

Tweakie.

6893

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

« on: December 14, 2010, 01:30:07 PM »

Off hand I would say yes, but I have no experience of using a diode which I don't actually have the manufacturers specification for. It is important to know the maximum current that can be used as it is a very fine line between bright and blown.
Can the maximum current be decided by guesswork ? and if so how ? - these are questions for which I have no answer. If the diode cost nothing then there is nothing to be lost by trying or experimenting but some of these diode on eBay fetch real money and I think that 'trial and error' with these would be just plain daft.

Just my opinion but I am not a gambling man and never have been.

Tweakie.

6894

*****VIDEOS***** / Re: Vector Laser Engraving.

« on: December 14, 2010, 01:16:44 PM »

Thanks.

Daft really, but this was the first thing done with the new laser head (which was some 7 months in the building) so I am really quite proud of that little bit of MDF.

Tweakie.

6895

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

« on: December 14, 2010, 01:07:38 PM »

You are welcome my friend, copy anything you find useful.

I have now learned (took a while) that you never stop building a CNC because it is never ever finished -  it is just an ongoing project. 

Tweakie.

6896

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

« on: December 14, 2010, 11:31:21 AM »

It must be 18 months since I last used the diode laser but from memory it was 10 volts input to the control panel.

Go on get a CO2 tube (ex.MOD), you could do real damage to wood and foam then. 

Tweakie.

6897

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

« on: December 14, 2010, 11:03:20 AM »

Sorry to hear that.

Is the device lasing ?
Are you sure it is not 12 Volt operation ?

100mV is not ideal but you should be able to burn black colored plastic stuff.

Tweakie.

6898

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

« on: December 14, 2010, 06:39:07 AM »

My sympathy's - I have been there, done it and read the book 

Dar303's posting here is also relevant to your project   http://www.machsupport.com/forum/index.php?topic=16760.new;topicseen#new

Tweakie.

6899

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

« on: December 14, 2010, 06:22:17 AM »

Hi Cosha,

I think that using the lithium pack is a brilliant idea, certainly a clean supply (no spikes at switch on etc.).

The laser has to be focused to the tiniest possible dot (size of a pin prick) to be effective but 1mW is just not enough power. You need at least 150mW to be in with a chance but 1 Watt would be even better.

Tweakie.

(I have said this before but please be extremely careful with diode lasers, the beam reflects of almost anything and you must wear protective goggles of the correct wavelength at all times. The wavelength of these devices makes them many many more times dangerous to our eyesight than, for example CO2 lasers.)

6900

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

« on: December 14, 2010, 05:52:03 AM »

Hi Guys,

I am having so much fun with Art's Gearotic Motion that i just had to post another picture of some more laser cut gears.

Tweakie.