Messages

5391

General Mach Discussion / Re: laser software

« on: December 12, 2012, 02:03:38 AM »

As far a photographic images are concerned different materials will almost certainly require different techniques in order to achieve the best results.

For example to reproduce a photographic image on wood it could be processed as an 8 bit image producing (in theory) 256 shades of grey. It may take a bit of practice to get it just right but the results can be truly stunning.
Plastic, on the other hand, will not accept shades of grey so photographic images are usually pre-processed into a 1 bit image using a ‘Dot Dithering’ (or similar) technique to produce the illusion of shades. Again it is a technique that requires some practice.

You will need to collect a number of different softwares in order to explore these various techniques so there is not really a simple answer to your first question.

May I suggest that you browse through this thread. http://www.machsupport.com/forum/index.php/topic,12444.80.html
It has become far too long to read everything so just scan trough, looking at the pictures and when you see something similar to what you want to produce, read the post which should explain how it was done and what software was used.

Tweakie.

5392

General Mach Discussion / Re: laser software

« on: December 11, 2012, 12:18:02 PM »

What is the material you will be using ??

Tweakie.

5393

General Mach Discussion / Re: laser software

« on: December 11, 2012, 06:13:14 AM »

Something like Vectric VCarvePro would take care of all your cutting and text engraving requirements.

It depends on what type of images you want to laser produce but the Mach3 Impact / Laser plugin works well for me.

Tweakie.

5394

Show"N"Tell ( Your Machines) / Re: Mach3 controlling CO2 Laser - progress and some tips on alignment

« on: December 10, 2012, 09:07:30 AM »

Hi Steve,

Excellent work with the laser building and beam alignment / setup video etc.

If  I may be so bold as to make a suggestion, there is just one additional test that you perhaps may want to add to your alignment video – that the laser beam exits the nozzle at 90 degrees to the work table in both planes.

This, to a large extent, is determined by the position at which the beam hits the final mirror and it is easily checked by placing a piece of acrylic on it’s side on the work table in line with the X axis and firing the laser into it then checking that the resultant cut / hole is in fact square (and repeated again for the Y axis plane).

If this aspect is not set correctly then any thicker parts cut will not have vertical sides so IMO it is an important part of the alignment process.

Keep up the laser work and I look forward to seeing some more pictures / postings of the things that you make with it.

Tweakie.

5395

Show"N"Tell ( What you have made with your CNC machine.) / Re: My latest longer term project

« on: December 10, 2012, 07:29:29 AM »

Excellent. 

What is the project that you are building Chris ??

Tweakie.

5396

Mach4 General Discussion / Re: New people welcome !! Come in here and introduce your self!

« on: December 10, 2012, 01:47:06 AM »

Hi Richard,

Welcome to the forum, nice to see another member from the UK.

Don't forget to post some pictures of the work you do with your new CNC machine.

Tweakie.

5397

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

« on: December 10, 2012, 01:42:58 AM »

Thanks Guys.

Tweaks does this assume that the 2 points are inline with the axis when referenced back to the drawing ?  IF not you have to account for that offset as well.  

Just a thought, (;-) TP

Hi Terry,

Yes indeed sir, you are quite correct.

If the Datum and Reference are vertically in-line (the angle is zero) then work re-positioning only takes the one referencing operation.

If the Datum and Reference are not in-line then the angle has to be referenced / calculated at the time of manufacture and stored.
Work repositioning can then be carried out by calculating the new angle, retrieving the original angle, subtracting one from the other then using the result for the Local System Rotate.

Tweakie.

5398

General Mach Discussion / Re: Backlash strangeness

« on: December 09, 2012, 10:46:31 AM »

Hi Ansen,

I am pleased that you have got it all sorted.

Now I am looking forward to seeing some pictures of your multi-layer acrylic works. 

Tweakie.

5399

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

« on: December 09, 2012, 03:35:13 AM »

After some experimentation, this is what I have finally ended up with…

The camera can be used for X - Y tool positioning as follows;

By adding two new VB buttons to the Mach3 screen labeled Camera and Home;
Clicking the Camera button opens the video window, sets a slow jog rate and prompts for the Datum to be located.
Clicking the Home button closes the video window, resets the slow jog rate and moves both the X and Y axis (applying the offset) so that the spindle / tool is centered at the datum point.

The VB (Cypress Enable) scripts I have used to achieve this are as follows;

Camera button script;
 
Call SetUserLed(1102,1) 'open Klaus's video window
Call SetOemDRO(3,1) 'set slow jog rate to 1%
Code "(Locate Datum then click HOME)" 'message for status bar

Home button script;
 
SetUserLED(1103,1) 'close Klause’s video window
Call SetOemDRO(3,80) 'reset jog rate to 80%
Xs=GetOemDRO(59) 'read Xscale DRO
Ys=GetOemDRO(60) 'read Yscale DRO
Xmove = 70.850 * 1/Xs 'enter your camera offset here
Ymove = 1.070 * 1/Ys 'enter your camera offset here
Code "G91 G0 X" &Xmove & "Y" &Ymove 'make incremental move
While IsMoving () 'wait while that happens
Wend
Code "G90" 'go back to absolute moves
DoOEMButton (1008) 'zero X axis DRO
DoOEMButton (1009) 'zero Y axis DRO
Code "(Homing to Datum Complete)" 'message for status bar


To take advantage of the Local System Rotate function I have added 3 new VB buttons labeled A, B & C.

Button A opens the video window, sets a slow jog rate and prompts for the Datum to be located.
Button B resets the X an Y axis DRO’s to zero and prompts for the reference to be located.
Button C closes the video window, resets the slow jog rate, performs the calculations and moves the X an Y axis so the spindle / tool position is centered on the Datum location then sets the Local System Rotated DRO to the calculated value. The scripts I have used are as follows;

Button A script;
 
Call SetUserLed(1102,1) 'open Klaus's video window
Call SetOemDRO(118,0) 'reset system rotate DRO
Code "(Locate Datum then click Button B)" 'message for status bar
Call SetOemDRO(3,1) 'set slow jog rate to 1%

Button B script;
 
DoOEMButton (1008) 'zero X axis DRO
DoOEMButton (1009) 'zero Y axis DRO
Code "(Locate Reference then click Button C)" 'message for status bar

Button C script;
 
Sub Main()
Call SetUserLed(1103,1) 'close Klaus's video window
X1pos = GetOemDRO(800) 'read x axis DRO
Y1pos = GetOemDRO(801) 'read y axis DRO
If (Y1pos=0) Then GoTo Label1 'avoid divide by zero error
b = Atn(X1pos/Y1pos)*(180/(4*Atn(1))) 'calculate angle
b = b - (b*2) 'change sign (+/-)
Code "G0 X0 Y0" 'move to datum
While IsMoving () ‘wait for task to be completed
Wend
Xmove = 70.850 'enter your camera offset here
Ymove = 1.070 'enter your camera offset here
Code "G91 G0 X" &Xmove & "Y" &Ymove 'make incremental move
While IsMoving () ‘wait while that happens
Wend
Code "G90" 'go back to absolute moves
Call SetOemDRO(118,b) 'set system rotate DRO
Label1:
DoOEMButton (1008) 'zero X axis DRO
DoOEMButton (1009) 'zero Y axis DRO
Call SetOemDRO(3,80) 'reset jog rate to 80%
Code "(Process complete)" 'message for status bar
End Sub

(With both the Home button and the C button scripts my camera offset should be changed to suit your particular machine).

Obviously, everything is ‘work in progress’ and there will always be room for improvement so please feel free to change these scripts, as necessary, to suit your own particular application. My solution is presented here just as a guide for future development.

One further thought…
 
If, for example, a round circuit board was made and a datum and a reference had been established and the angle calculated (as mentioned above). This angle (angle1) could be stored as a VAR. If the round circuit board was removed from the work table then replaced (at a different angle) then by locating the same datum and reference and again calculating the angle (angle2) by subtracting one from the other the resultant angle when entered into the Local System Rotated DRO would be correct for work to be re-commenced on the circuit board as if it had never been removed and replaced.
 
It would perhaps be quite complicated to perform all the necessary math’s using a calculator but by using a VB script it could not be made more easy.

Tweakie.

5400

Show"N"Tell ( Your Machines) / Re: New Built - Beginning Stages

« on: December 08, 2012, 09:05:44 AM »

Hi Zig,

Ideally, of course, it would be best to use the purpose made (fully supported) linear slides but unfortunately they come at a price. However, there are many that have successfully used the draw slides for their CNC build but be aware that they can have their disadvantage…

I use some miniature (high cost, professional) versions, for laser optics positioning (which work on the same principal) and although they are smooth and very low friction sooner or later the cage, containing the balls, gets out of step with the slide - then they become ‘high friction’ when the balls have to 'skid' in order for the slide to reach it’s end stop and reset the cage positioning. 

Please keep posting details, pictures or video links of you build – we all like to see pictures. 

Tweakie.