Messages

4901

General Mach Discussion / Re: How to zero "machine coordinates" of cnc with no switches of any kind using Mach

« on: February 16, 2013, 04:17:35 AM »

Hi Bugatti,

Welcome to the forum.

If I understand your question correctly (and I often get this part wrong) I think you need to set the Origin (X & Y zero) within ArtCam at the bottom left hand corner of your stock.
Then, when the stock is placed on your machine table, jog your axes until the cutter is positioned to the bottom left hand corner of the stock (Origin) then Zero the X and Y axes DRO’s. Presumably your Z axis zero is the top surface of the stock so you need to jog your Z axis until the cutter touches the surface of the stock then Zero your Z axis DRO. Now jog the Z axis until the cutter is clear of the stock surface and you should now be ready to Run.
However, it is always worth checking the Program Limits in the Toolpath screen to make sure that the X, Y & Z ranges are within the dimensions of your stock before you begin.

I don’t know if this helps but this is the way I work, totally ignoring machine coordinates, homing routines, etc.

Tweakie.

4902

G-Code, CAD, and CAM discussions / Re: Mach3 adding extra loops in a string of arcs

« on: February 16, 2013, 03:58:41 AM »

Hi Guys,

I am sorry to be an absolute pain but obviously I am missing something here. 

I ran the posted ‘fender jaguar.txt’ file last week and could not see any problems – could you please enlighten me on just what the problem is ?

Tweakie.   

4903

Tangent Corner / A Microscopic view.

« on: February 16, 2013, 03:06:36 AM »

An interesting video showing what happens when we machine metals (and presumably other materials)   http://www.youtube.com/watch?v=mRuSYQ5Npek&feature=player_embedded#!

Tweakie.

4904

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

« on: February 16, 2013, 02:24:33 AM »

Hi Richard,

Thank you for the information, it is most useful to know what causes and cures problems as this will inevitably be of help to others that follow.

That damn Watchdog - I suppose it is of use to somebody 

Tweakie.

4905

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

« on: February 15, 2013, 04:08:59 AM »

I have been following recent work (done on another forum) with low power lasers producing images using printer Toner.

I had to give it a try using my 40W CO2 laser and this was my first successful test run on a scrap piece of Oak.

IMPORTANT - It should be noted that it is unwise to experiment with fine powders in a confined space so for any that follow please observe the necessary safety precautions and always have a suitable fire extinguisher standing by.

Tweakie.

4906

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

« on: February 15, 2013, 04:04:40 AM »

Hi Yanxin,

I am looking forward to seeing some pictures of your work.

(You are quite correct about the Impact / Laser plugin - it uses a fixed time interval (PWM) of 40uS and a variable repetition frequency (PRF) of between 0 and 12.5 kHz and, of course, fires the laser whilst the axis is moving).

Tweakie.

4907

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

« on: February 14, 2013, 12:44:11 PM »

Hi Yanxin,

DotG has been designed for reproducing a one bit, ‘dot-dithered’ image (one with a varying density of equal sized dots to create the illusion of shade) and when set in ‘dot’ mode the laser is only fired when the X and Y axes are stationary.

To fire the laser I am using the M11P1/M10P1 command set together with an imaginary B axis and my Post Processor (see posting #641) essentially creates this code for each dot in the image:-

B0

M11P1 B1
M10P1 B0

B0 is at the start of the code and makes sure the imaginary B axis is in position 0.

M11P1 turns on Output #1 (as soon as the B axis starts to move). Output #1 is mapped to an LPT (parallel port) output pin which is in turn connected to my laser TTL(L) trigger.
Because the imaginary B axis takes time to move from position 0 to position 1, I have adjusted (by trial and error) the steps per unit, Velocity and Acceleration of this axis to produce the required time delay (laser on time).

M10P1 turns off Output #1 and thus the laser trigger as soon as the B axis starts to move back to position 0.

I hope this answers your questions.

Tweakie.

4908

*****VIDEOS***** / Re: Laser Cut Frame CNC Router New build

« on: February 14, 2013, 05:51:43 AM »

Hi John,

I have never been an advocate of belt traverse but I obviously need to do a re-think as you certainly have shown that a high degree of positional accuracy can be obtained with your (hive mind) design.

What sort of things are you planning on making with the new machine ?

Tweakie.

4909

Show"N"Tell ( Your Machines) / Re: 4 axis bedmill retrofit

« on: February 14, 2013, 05:39:50 AM »

Hello Machine Head

Autolisp?

I have an Acad license. If it is not your personal IP I would be very interested in trying it.

Cheers
John McNamara 

Autolisp details are here http://www.jefferypsanders.com/autolisp.html

Tweakie.

4910

General Mach Discussion / Re: New PlugIn just about done..

« on: February 14, 2013, 05:22:11 AM »

If it's of any interest...

Something very similar regarding axis creep after jogging came up here http://www.machsupport.com/forum/index.php/topic,23460.0.html

As far as I know, it was not resolved.

Tweakie.