Messages

8501

Show"N"Tell ( Your Machines) / Re: motion test on the horizon...

« on: June 04, 2009, 11:11:22 AM »

Very neat Barry - I wish my wiring was that tidy.

Tweakie.

8502

Show"N"Tell ( Your Machines) / Re: My New Router Gantry Build

« on: June 04, 2009, 11:08:41 AM »

Looking good Gary.

Tweakie.

8503

Show"N"Tell ( What you have made with your CNC machine.) / Laser Cut Gaskets using a low power laser.

« on: June 04, 2009, 11:00:55 AM »

My favorite model plane has an aging OS 61 which is now due for new crankshaft bearings and a clean up. The new crankcase gaskets have always been a pain to make (can’t buy them anymore – people don’t still use engines this old) and as I saw a posting recently about laser cut gaskets I decided to give it a try. I scanned the crankcase and got a reasonably good image which I converted to vector and then to GCode. Cutting at only 40 mm/min the 150mW laser made a pretty good job and didn’t set fire to the thin material as I half expected it to.

A couple of pictures of the laser and it’s control box on my Z axis, the finished gaskets and where they fit on the crankcase.

Tweakie.

8504

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

« on: June 02, 2009, 12:26:53 PM »

Yea -  Australia prohibits imports of anything greater than 50 mW.

Never tried green lasers either - please post your results.

Tweakie.

8505

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

« on: May 29, 2009, 04:16:16 AM »

Thanks for the kind words Kent.

One thing about using lasers is that there is no loading on the tool head therefore even converted pen plotters would be good to use. You need to have no worries about MDF with low power lasers - the worst that could happen is a few scorch marks perhaps. 

Tweakie.

8506

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

« on: May 27, 2009, 06:02:25 AM »

Why am I not surprised about the stiff neck ?.

Tweakie.

8507

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

« on: May 27, 2009, 05:16:44 AM »

Beautiful.

Tweakie.

8508

Show"N"Tell ( What you have made with your CNC machine.) / Re: Isolation Routing for PCB's.

« on: May 27, 2009, 03:38:53 AM »

Thanks Chris.

This one is a 'euro card' sized pcb made the same way.

Tweakie.

8509

Show"N"Tell ( What you have made with your CNC machine.) / Re: Isolation Routing for PCB's.

« on: May 27, 2009, 01:52:19 AM »

I am using a 30 degree engraving point and cutting 0.08mm deep.

Tweakie.

8510

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

« on: May 25, 2009, 09:27:34 AM »

Hi Mark,

Thanks for your input on this thread.
 
I have a 'Q Switch' on my YAG laser which does as you say bend the beam but It is too large for this project also it is designed specifically for 1064 nm and not a 655 nm red laser. I will check ebay more often to see if anything comes up.

After much experimentation I have now decided to use a shutter system for beam on/off which is driven by a small 4 position stepper motor (couldn't find a galvo without having to buy a disco light and stripping it for the parts) linked to the Z axis direction signal. It is quite fast in operation, performs like a galvo and seems OK. I am using PRF modulation of a 20nS pulse for control of the diode power output but am still experimenting with different pulse widths and modulation circuits.

To me, probably the most surprising thing about this project is that low power lasers do have useful applications with CNC machines.

Best regards,

Tweakie.