Messages

8271

Tangent Corner / Re: CNC fire hazzard.

« on: July 07, 2009, 01:38:41 AM »

Hi Daniel,

It wasn't my machine, fortunately.
It appears that it was a mechanical fault when the leadscrew nut broke free from it's mounting and allowed the Z axis to drop.

Tweakie.

8272

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

« on: July 07, 2009, 01:33:08 AM »

Brilliant.

Tweakie.

8273

Tangent Corner / CNC fire hazzard.

« on: July 06, 2009, 09:15:21 AM »

Just look and see what happened when this Z axis failed and plunged the plastic bodied spindle into the work and stalled the spindle.
Perhaps the lesson is to make sure the correctly rated fuse or circuit trip is always used for the spindle when machines are left operating unattended.

http://www.flickr.com/photos/29506322@N08/sets/72157620853267251/

Tweakie.

8274

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

« on: July 06, 2009, 02:34:30 AM »

Hi Bill,

Initially I did edit out the Z moves but have now found that there is advantage to leaving the code 'as is'. I now disable the Z axis movement and make use of the Z code, by altering the Z Axis DRO scale factor to set the required dwell time.

Guy is, of course, quite right - If you want to do serious work then you need a serious laser and as we already know, nothing in the world of CNC comes cheap.

Tweakie.

8275

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

« on: July 05, 2009, 10:46:12 AM »

Hi Bill,

As far as I can remember the feedrate was set at 30 mm/minute so total time would have been around 15 minutes per gasket. OK it is very slow but then I have all the time that God has decided to allow me.

Tweakie.

8276

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

« on: July 05, 2009, 08:38:41 AM »

Hi everybody,

More for information only, as I have already posted the picture on another thread, but these little gaskets were cut with a 150 mW diode laser.
The crankcase was scanned (on my printer/scanner) and the image converted to vector and then to GCode. The gaskets produced are a perfect fit and probably a good example of what can be achieved.

Tweakie.

8277

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

« on: July 05, 2009, 03:53:49 AM »

Hi Bill,

I will try to answer your questions as best I can. Please note that this is not definitive but just my opinions based on my experiences so far.

A. I have no working knowledge of these Turkish lasers as no one has yet reported back on their use. Provided the supplied lens will actually focus the beam to a spot the size of a pin point (within the available space on your machine) then the 1 Watt of laser power looks good.

B. Additionaly you will, I think, need to cool the diode casing with a larger heatsink and perhaps CPU type fan.

C. I have no recommendations.

D. Using a laser which is only 1/7 the power of this one - I have not had too much trouble with engraving different types of wood however the surface reflectivity of the wood is the controlling factor and a finely sanded surface seems to be better. Surface burn marks adjacent to the cuts are a problem to control however.

E. I suggest just laying the work onto a sacrificial board such as plywood would be OK.

Good luck with your project Bill - Please report back to the forum with your results.

Tweakie

8278

Show"N"Tell ( Your Machines) / Re: emco pc5 lathe

« on: July 02, 2009, 12:54:58 PM »

Extremely neat work.

Tweakie.

8279

Show"N"Tell ( What you have made with your CNC machine.) / Re: Plaque of Neptune for above my stairwell. :)

« on: June 30, 2009, 02:53:03 AM »

Nice one Sam, looks really good.

Tweakie.

8280

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.