Messages

7321

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

« on: May 21, 2009, 03:20:52 AM »

OK Chris, I see the application - brilliant idea. If you use modulation to control the laser (0 to 15kHz say) you will be able to have full command over the amount of radiated power from the laser for any feed rate that you choose. I have not seen modulation units for sale but it would be relatively easy to construct, I think, using a 555 timer or the like to create a variable PRF of a fixed width pulse. I will give this more thought and report back.

Tweakie.

7322

Show"N"Tell ( What you have made with your CNC machine.) / Re: Gertrude Gets Some!

« on: May 20, 2009, 07:08:18 AM »

You have just gotta get more sleep buddy.

Tweakie.

7323

Show"N"Tell ( What you have made with your CNC machine.) / Re: Gertrude Gets Some!

« on: May 19, 2009, 12:38:50 PM »

Thanks Chris - I can tell that it is 2 am. 

Tweakie.

7324

Show"N"Tell ( What you have made with your CNC machine.) / Re: Gertrude Gets Some!

« on: May 19, 2009, 07:50:12 AM »

Chris,

How and where do you now attach the sprue to pour the casting now that the hub has been removed ?.

Tweakie

 

7325

FAQs / Re: Laptop requirements with Mach 3

« on: May 19, 2009, 07:47:13 AM »

This is certainly a good forum with so many people sharing their ideas and solutions to problems.

Tweakie.

7326

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

« on: May 19, 2009, 07:38:27 AM »

Chris - In the process of experimentation I have concluded that a shutter system (to turn the laser on and off) is preferable to using the modulation input (at TTL levels). This enables the laser diode to be operated by a completely isolated constant current source and eliminates any possibility of voltage spikes from the machine or computer causing any damage to the diode. I have detailed what I have done so far on my website and the link is below. I will include the shutter details when I have time. Good luck and I look forward to seeing your results.

                                          http://www.cooperman.talktalk.net/index_files/Page4549.htm

Tweakie.

btw. thanx for the links Martin.

7327

Show"N"Tell ( What you have made with your CNC machine.) / Re: Gertrude Gets Some!

« on: May 17, 2009, 02:36:19 AM »

Right - now it all makes sense. 

Tweakie.

7328

Show"N"Tell ( What you have made with your CNC machine.) / Re: Gertrude Gets Some!

« on: May 17, 2009, 01:35:15 AM »

Just curious Chris, but is Gertrude the name of your machine ?

Tweakie.

7329

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

« on: May 16, 2009, 04:07:29 AM »

Dave reminding me about the magnifying glass as a kid led me to think about an offset parabolic satellite dish on a polar mount with the dish actuator driven by a simple 2 photo diode sun tracking system – assuming the dish was steel it could be chrome plated and polished with a water cooled collimating lens fitted in place of the LNB. This collimating lens would feed into a gas cooled fiber optic cable that was led to the CNC Z axis and in turn a water cooled focusing lens. OK it is straight out of the James Bond film but it is not rocket science and may not be practical here in the UK because of the frequent cloud cover but for some of you guys in North America it could be a practical proposition. It would not produce megawatts of power but I bet it would be more than the 150 mW I am currently using.

What do you think, would it work ?.

Tweakie.

7330

Show"N"Tell ( What you have made with your CNC machine.) / Re: Some new toys for my Taig

« on: May 16, 2009, 04:05:54 AM »

That is just great Dave. You now have the smartest looking mill in the country. 

Tweakie.