Low cost laser

This forum is for users to post tips and tricks they have found useful while working with VCarve Pro
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pedio
Posts: 21
Joined: Wed Dec 23, 2015 8:56 pm
Model of CNC Machine: Routermaster running Mach4

Low cost laser

Post by pedio »

I was asked some questions about where I got my laser and what it took to add to the CNC machine. The forum does not let me private message so here is my response.

I purchased the L-Cheapo laser 3.5W version 3.0 at http://3dsupplysource.com/L-CheapoV3

My laser is driven by a PWM control (this is another $5 and you need to contact the manufacturer if you want a laser with PWM. PWM allows you to control the power of the laser instead of just turning it on and off.

I used a spindle control on my CNC to provide the PWM signal. The only real problem was the PWM signal and the power share a common ground. This means you need 12V and the PWM on the same ground.

The mount for the laser needs to be very stiff. If there is any movement the laser will give very interesting patterns. I mounted the laser to the front of the spindle that was already on the machine.

I set up the laser in the CNC software to have a spindle speed 1-100 (100 is max power). I use different tools in V-carve to change the spindle speed (really don't use this much - it is easier to just move the laser faster or slower)

I use V-carve Pro to control the laser. You need to set up a sample file for your laser. Since I am using plunge and retract to turn on the laser the plunge rate needs to be high and the distance needs to be short. The laser comes on when it first sees the signal and was causing little dots at the beginning / end of the lines. The post processor I made took out all of the Z movement so the machine does not change the distance to the table.

The engrave toolpath seems to work well for most lettering. It fills the area in with black quite nicely.

The laser has a focal length of around 2.8" and you need to focus it when you first put it on the machine. I made a couple of dowels that show the distance to the work piece. I have one for normal, ultra thin, and thick. For art work I have found a thicker line is better.

I added a button to my CNC control software that turned on the laser at a speed of 1 (lowest). This allows me to center it on the piece without burning a little hole. This is why you really need PWM.

I wrote the following post processor for V-carve / Mach 3

+================================================
+
+ Mach2/3 - Vectric machine output configuration file
+
+================================================
+
+ History
+
+ Who When What
+ ======== ========== ===========================
+ Tony 15/11/2005 Written
+ Tony 06/01/2006 Added ATC option
+ Tony 14/05/2006 Fixed G20 inch in header
+ Tony 24/07/2006 Added G2 & G3 Arc support + removed (( ))
+ Tony 18/06/2007 Replaced the Tool comment
+ Mark 14/08/2008 Added G1 to Feed moves, added New_Segment
+ Removed 2nd G20 in header.
+ Mark 28/08/2009 Added G91.1 to force use of incremental arcs
+ Added Substitution, File & Toolpath Notes.
+ Mark 30/11/2009 Added TOOLPATHS_OUTPUT.
+ Brian 15/12/2009 Remove M05 from NEW_SEGMENT
+ Mark 18/01/2014 Added Dwell
+Peter 2/1/16 Converted to Laser
+Peter 2/3/16 Used plunge and retract commands instead of spindle start on each move to avoid jerkey moves
+================================================

POST_NAME = "Mach Laser Arcs (inch) (*.txt)"

FILE_EXTENSION = "txt"

UNITS = "inches"

DIRECT_OUTPUT = "Mach|Mach4.Document"

SUBSTITUTE = "({)}"

+------------------------------------------------
+ Line terminating characters
+------------------------------------------------

LINE_ENDING = "[13][10]"

+------------------------------------------------
+ Block numbering
+------------------------------------------------

LINE_NUMBER_START = 0
LINE_NUMBER_INCREMENT = 10
LINE_NUMBER_MAXIMUM = 999999

+================================================
+
+ Formating for variables
+
+================================================

VAR LINE_NUMBER = [N|A|N|1.0]
VAR SPINDLE_SPEED = [S|A|S|1.0]
VAR FEED_RATE = [F|C|F|1.1]
VAR X_POSITION = [X|A|X|1.4]
VAR Y_POSITION = [Y|A|Y|1.4]
VAR Z_POSITION = [Z|A|Z|1.4]
VAR ARC_CENTRE_I_INC_POSITION = [I|A|I|1.4]
VAR ARC_CENTRE_J_INC_POSITION = [J|A|J|1.4]
VAR X_HOME_POSITION = [XH|A|X|1.4]
VAR Y_HOME_POSITION = [YH|A|Y|1.4]
VAR Z_HOME_POSITION = [ZH|A|Z|1.4]
VAR SAFE_Z_HEIGHT = [SAFEZ|A|Z|1.4]
VAR DWELL_TIME = [DWELL|A|P|1.2]
+================================================
+
+ Block definitions for toolpath output
+
+================================================

+---------------------------------------------------
+ Commands output at the start of the file
+---------------------------------------------------

begin HEADER
"( [TP_FILENAME] )"
"( File created: [DATE] - [TIME])"
"( for Mach 2,3,& 4)"
"( Material Size)"
"( X= [XLENGTH], Y= [YLENGTH], Z= [ZLENGTH])"
"([FILE_NOTES])"
"(Toolpaths used in this file:)"
"([TOOLPATHS_OUTPUT])"
"(Tools used in this file: )"
"([TOOLS_USED])"
"[N]M05"
"[N]G00G20G17G90G40G49G80"
"[N]G70G91.1"
"[N] (Tool: [TOOLNAME])"
"[N](Toolpath:- [TOOLPATH_NAME])"
"[N]([TOOLPATH_NOTES])"
"[N]G94"
"[N][XH][YH][F]"

+---------------------------------------------------
+ Commands output for rapid moves
+---------------------------------------------------

begin RAPID_MOVE

"[N]M05"
"[N]G00[X][Y]"


+---------------------------------------------------
+ Commands output for the first feed rate move
+---------------------------------------------------

begin FIRST_FEED_MOVE

"[N]G1[X][Y][F]"


+---------------------------------------------------
+ Commands output for feed rate moves
+---------------------------------------------------

begin FEED_MOVE

"[N]G1[X][Y]"

+---------------------------------------------------
+ Commands output for the first clockwise arc move
+---------------------------------------------------

begin FIRST_CW_ARC_MOVE

"[N]G2[X][Y][J][F]"

+---------------------------------------------------
+ Commands output for clockwise arc move
+---------------------------------------------------

begin CW_ARC_MOVE

"[N]G2[X][Y][J]"

+---------------------------------------------------
+ Commands output for the first counterclockwise arc move
+---------------------------------------------------

begin FIRST_CCW_ARC_MOVE

"[N]G3[X][Y][J][F]"

+---------------------------------------------------
+ Commands output for counterclockwise arc move
+---------------------------------------------------

begin CCW_ARC_MOVE

"[N]G3[X][Y][J]"


+---------------------------------------------------
+ Commands output for a new segment - toolpath
+ with same toolnumber but maybe different feedrates
+---------------------------------------------------

begin NEW_SEGMENT

"([TOOLPATH_NAME])"
"([TOOLPATH_NOTES])"

+ ---------------------------------------------------
+ Commands output for Retract Moves
+ ---------------------------------------------------
begin PLUNGE_MOVE

"[N][S]M03"

+ ---------------------------------------------------
+ Commands output for Retract Moves
+ ---------------------------------------------------
begin RETRACT_MOVE

"[N]M05"

+---------------------------------------------
+ Commands output for a dwell move
+---------------------------------------------

begin DWELL_MOVE

"[N]G04 [DWELL]"

+---------------------------------------------------
+ Commands output at the end of the file
+---------------------------------------------------

begin FOOTER

"[N]M05"
"[N]G00[XH][YH]"
"[N]M09"
"[N]M30"
%

Frunple

Re: Low cost laser

Post by Frunple »

Nice post. Thanks!

If you ever figure out the PM problem, let me know. I can't send them either. I get email saying I received a PM, just can't get to it.

pedio
Posts: 21
Joined: Wed Dec 23, 2015 8:56 pm
Model of CNC Machine: Routermaster running Mach4

Re: Low cost laser

Post by pedio »

When I first got my laser it used the wrong board. The board version number is between the resistors on the back. It needs to be at least v2.7. Once I got the right laser it worked fine. The previous one would not see the change of state fast enough in some cases; e.g., line segments would be missing or wrong power level.

The Version 3 laser is actually pretty powerful. Not enough to mark metal but more than enough for wood and to cut gasket material. I want to try it on some decal material and sandblast mask. I have been burning logos into everything since I got this working.

GeneMpls
Vectric Craftsman
Posts: 193
Joined: Sun Nov 04, 2012 4:27 pm
Model of CNC Machine: PRS Buddy48alpha ,4x6' 130w laser, Wazer

Re: Low cost laser

Post by GeneMpls »

To mark metal there is a liquid or tape that is applied first- then the metal will be permanently marked. Cermark (I think)

pedio
Posts: 21
Joined: Wed Dec 23, 2015 8:56 pm
Model of CNC Machine: Routermaster running Mach4

Re: Low cost laser

Post by pedio »

I think you need a much more powerful laser to use the marking tape or fluid. Not sure but they talk about CO2 lasers. Mine does a good job burning wood or leather.

User avatar
ChrisInEstes
Vectric Wizard
Posts: 841
Joined: Fri Jul 17, 2009 8:00 pm
Model of CNC Machine: Vytek 4' X 8' - Perske Spindle - Mach3
Location: Estes Park, Colorado, USA

Re: Low cost laser

Post by ChrisInEstes »

pedio wrote:When I first got my laser it used the wrong board. The board version number is between the resistors on the back. It needs to be at least v2.7. Once I got the right laser it worked fine. The previous one would not see the change of state fast enough in some cases; e.g., line segments would be missing or wrong power level.

The Version 3 laser is actually pretty powerful. Not enough to mark metal but more than enough for wood and to cut gasket material. I want to try it on some decal material and sandblast mask. I have been burning logos into everything since I got this working.
I sent a PM to you again. I'll send some sandblast mask to you if you like.

Hopefully you can send a receive PMs by now. If not, maybe somebody at Vectric can step in and allow your message privileges.

Chris
Aspire 9.5 - FlexiEXPERT 11 - Vytek Rebel 4' x 8' - 5HP Perske Spindle

pedio
Posts: 21
Joined: Wed Dec 23, 2015 8:56 pm
Model of CNC Machine: Routermaster running Mach4

Re: Low cost laser

Post by pedio »

Do you have a link where I can buy sand blast gasket? I will try a little. The laser cuts stuff pretty well.

User avatar
ChrisInEstes
Vectric Wizard
Posts: 841
Joined: Fri Jul 17, 2009 8:00 pm
Model of CNC Machine: Vytek 4' X 8' - Perske Spindle - Mach3
Location: Estes Park, Colorado, USA

Re: Low cost laser

Post by ChrisInEstes »

I buy mine by the roll from my wholesale sign supply co., Midwest Sign Supply.

---> http://www.midwestsign.com/

It's pricey... Around $20 per yard for the 15" wide stuff.

There is also Hartco brand, which is vinyl. It's been 15+ years since I've used anything from Hartco.

With the textures that Vectric software can create, I may not need to use it again.

Chris
Aspire 9.5 - FlexiEXPERT 11 - Vytek Rebel 4' x 8' - 5HP Perske Spindle

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