Messages

6321

Show"N"Tell ( What you have made with your CNC machine.) / Re: Using Biodiesel as a machining fliud - Video

« on: August 17, 2011, 09:26:17 AM »

You need an agent, ingnition source, and oxygen. There is a low and high level of ignition and also the enviroment condition comes into play.
Pop just didn't have the right condition. Didn't mom ever tell you that if you play with matches you'll get burnt! 

RICH

 

Tweakie.

6322

Show"N"Tell ( What you have made with your CNC machine.) / Re: Using Biodiesel as a machining fliud - Video

« on: August 17, 2011, 01:55:15 AM »

I always use a fan in my workshop to blow the smoke away from me when cutting.  I used to use expensive Rocol cutting oil for heavy cuts in my manual lathe and it gives off  similar amounts of very obnoxious smoke.

That is just about the worst thing you could do - stir up the air, mixing in any toxic particles from the diesel (which are seldom visible) 
A better solution may be an extractor system.

Tweakie.

6323

General Mach Discussion / Re: Has anyone used a program called "Image to gcode"?

« on: August 16, 2011, 04:48:58 AM »

Hi Mike,

I tried it a while back and thought it was pretty good.
It has a 30 day trial period so you can 'try before you buy' - you can't beat that.     http://imagetogcode.com/Download.htm

Tweakie.

6324

Show"N"Tell ( What you have made with your CNC machine.) / Re: Using Biodiesel as a machining fliud - Video

« on: August 16, 2011, 04:08:23 AM »

Hi Chris,

Take care inhaling that smoke.  

Research has shown that the particulates produced from biodiesel are indeed less harmful to health than from diesel fuel but the research did not cover any long term exposure and as you are mixing it 3:1 with diesel anyway, well...........

There is an engineering shop near me and at break time many of the employees stand outside smoking cigarettes and breathing in the fumes from the passing traffic  

Tweakie.

6325

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

« on: August 16, 2011, 01:26:23 AM »

Hey naPS,

That's brilliant, looks like you are really getting the hang of it. Thanks for posting the pictures (we all love pictures).

(with deep engraving of wood / plastic I use paper transfer tape [used for vinyl sign application] - this prevents the surface smoke discolouration and is easily removed after the work is completed  ).

Tweakie.

6326

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

« on: August 15, 2011, 12:01:10 PM »

Hi John,

Sounds as though you have the 'Ports and Pins' set up correctly and that the problem may be feedrate related.

The plugin's output on the digital trigger is dependant on the Kernel speed, the image pixel value and the axis feedrate - currently, the Kernel speed should be 25000Hz  and the axis feedrate set in motor tuning somewhere between 4,000 and 20,000 mm/min with the plugin feedrate set somewhere above 300 mm/min.
If your laser diode has good response then you are in with a chance but it is pretty much 'trial and error' here.

As an example, my true X Axis feedrate is 4,500 mm/min and I set the plugin feedrate to 15,000 mm/min and this just squeaks in at the bottom end of the requirements for a CO2 tube which has really poor response at the lower end of the power scale.

Experiment with the feedrates and let me know if this resolves the problem.

Tweakie.

6327

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

« on: August 15, 2011, 04:19:20 AM »

Hi Amir,

I use 5mm pitch ballscrews and my maximum, 100% reliable, G0 and laser feedrate is 4,500mm/min.

I doubt belt drive would improve my machine speed because of the mass of my combined X and Z axis but a purpose built machine could perhaps exceed 20,000mm/min without too much effort.

Tweakie.

6328

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

« on: August 15, 2011, 02:49:45 AM »

Thanks Dave. 

Hi Amir,

The image size is 90mm x 90mm with 0.15mm stepover. I don't remember the exact times but the laser took minutes (at 4500mm/min) and the magnet took hours (at 300mm/min).

I certainly like the idea of an air operated solenoid, particularly if it could be operated faster than a magnet.
Because the moment of impact lags behind the trigger event and the plugin operates in bidirectional mode, currently, any increase in feedrate beyond 300mm/min results in noticeably staggered verticals.
It's a challenge, but even a small increase in impact speed could reduce process time considerably.

Tweakie.

6329

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

« on: August 14, 2011, 08:30:44 AM »

Have you tried it yet ??

Tweakie.

6330

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

« on: August 14, 2011, 08:23:30 AM »

Hi Dave,

Andrea pioneered the magnet design which is driven from the Mach digital trigger by one phase of a bipolar stepper motor driver. The impact tip is, I think, tungsten carbide and it is ground to a very sharp point but what is perhaps most interesting is that it impacts the work on the return stroke so it is the spring pressure x travel distance (Z height) that determines the impact force and therefore the depth.

This Impact engraving is not something that will necessarily work 'straight out of the box' because my first attempts were just terrible but with the right setup the results are, I think, quite stunning.

Tweakie.