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Messages - maxem

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OpenLase Discussion / Re: LaserShark / Openlase / Raspberry Pi ?
« on: March 04, 2015, 07:58:26 PM »
Sorry for the long delays between posts, been busy with multiple projects.

I know this is way off topic, not sure if I should start a new thread about this...
I have been thinking about using the lasershark to help with alignment of material and hold down supports on a cnc machine. 
This year I will be building a large cnc machine from scratch for simple cutting out of sheet goods with a spindle and also a tangential razor blade for cutting veneers.  I need to make this machine idiot proof because I will not be the only one running it. 

I think lasershark would help an operator see where the toolpaths are going to go before hitting the Start button so that crashes with hold down screws/fixturing does not happen.  Also it would help with alignment of veneers and odd shaped materials.  Or to tweak placement to avoid knots in wood etc.

I don't know how much experience you have with cnc machines but I have been thinking maybe its possible to use a CAM program to output the lasershark program.  Normally in CNC operations you create your G-code in a CAM program that has a post processor that matches your machine or you make your own custom post processor to work how you want it.  Maybe its possible to make a post processor that will output the format that the lasershark wants to see for X & Y movements and then the Z axis height output is used to vary the intensity of the laser.  Where the lowest Z height equals the highest laser intensity and the highest Z height equals the lowest laser intensity.  So that transfer moves, where the cutter picks up out of the material and moves to a new location and continues cutting, would either be of lower intensity or not appear visible at all.

This way you could output the toolpaths for the machine to cut with one CAM post processor and then switch to a lasershark post processor and output the lasershark file.

One problem with this is when using a cnc machine you usually have two different positions for home or X0,Y0,Z0  One is the machine coordinates that the machine homes or zeros itself to and then there are work offset coordinates that the operator sets to where the material is placed on the machine bed and the gcode is run from there (typically a G54,G55,G56 etc.).
  The problem with running the lasershark is that it would essentially always be aligned to the machine coordinates and getting it to change on the fly when the work coordinates that are changed by the operator would put the displayed pattern off of alignment from the cut.

It makes me think that the best way to go about this is to build a plugin to Mach4 that after you have loaded/opened the toolpath gcode file for the cnc machine, you could press a button to display the toolpath via the lasershark and the plugin would look at the machine gcode and subtract the current work offset coordinate from the machine coordinate and then output a file to the lasershark by saving it in a network folder for display for the lasershark.  And have the Rasp Pi or whatever always watching that folder and display that file automatically.  Every time you press the display via LaserShark button in Mach4 it would overwrite the file that the lasershark is looking for.

I still use Mach3 for one of my cnc machines and WinCNC for another.  The new machine I will build will be run by the new Mach4 controller.  I know writing a plugin for a CNC controller program might seem a little crazy but Mach has a huge diy cnc user base and just came out with the long awaited Mach4: http://www.machsupport.com/

I would like to explore this more when the new machine is built.  I really don't know anything about programming at all, I've built several arduino projects and understand that code but I know that's total beginner stuff. I'm really just a cnc guy that's good at 3D modeling. 


***OK this is embarrassing I just rechecked your youtube video before posting this and see you have your own cnc milling machine.  Where's that emote? oh yeah :-[  :-[  :-[

Please ignore the cnc explanation stuff I'm sure you know it all already, I could rewrite this post but maybe it will give someone else an idea or something.  Also it looks like you use linuxCNC so would you would not be interested in a Mach plugin, ugh.  Anyway the lasershark would be for a flatbed machine like this one I currently own (a video from 2 years ago:http://youtu.be/jeUpjhqeiHE ) but with an even larger bed for cutting thin sheet materials.
I know it wouldn't be useful on a milling machine like yours but on cnc routers like mine where the material is usually a 4'x8' sheet of plywood it could be useful because the easy way to hold down a plywood is to screw it down to your table in strategic places but avoiding hitting the screws is crucial and I think the lasershark could help a noob operator avoid hold downs and feel confident running the machine.
Sorry for the epic post.

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OpenLase Discussion / Re: LaserShark / Openlase / Raspberry Pi ?
« on: February 25, 2015, 08:50:06 AM »
Thank you  for the quick reply.  I have been looking into this more and see that I can even control the Rasp Pi from a windows computer through something like Tight VNC.  The cnc machine is controlled by a windows pc and would be great to control both laser projector and machine from one computer screen. 

From what I understand about the sample code format  x,y,a,b,c,intl_a

X and Y are positions
A and B are only used if you have a laser that is power controlled via analogue
C is only used if you have a ttl power controlled laser
and  intl_a  is like a  safety thing that is either on or off ?

If its really this simple I would imagine that I can take my CAD files and output them as a CSV file and convert the XY data into this format for the laser shark with the proper header and footer added to the file.

Even if the laser would be constantly on causing connecting lines between the different shapes I think it would still be very easy to discern the boundaries of shapes.

This is very interesting, even though I know nothing about coding I think this could be done in a way that makes it worth while to help speed up machine loading times.   I just have to find the fastest/least effort way to make it worth while.  The alternative is using a home theater projector and setting up a fixed camera view in the modeling program I use 3D Studio Max and projecting the camera view rendered image. But of course ambient light and focus are a problem.

  Perhaps a Script can be written in 3DS Max that can take the selected objects and create the lasershark file directly. 
That would be amazing.  I will be looking into this some more...
Thanks for all your help!
-Max


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OpenLase Discussion / Re: LaserShark / Openlase / Raspberry Pi ?
« on: February 20, 2015, 04:08:20 AM »
Hi, I am interested in what the simplest form of a Linux computer you could use to run the LaserShark.  I know nothing about linux so I was hoping the Rasp Pi 2 would be powerful enough cause there is so much Rasp Pi documentation on setup and stuff.

You say for "bulk transfers" the Rasp Pi should be good enough.  I have a bit of an odd use for the LaserShark I would like to use it to help with part/material alignment on a cnc machine. Like this:
http://www.carterproducts.com/technology/z-laser-model-lp-hfd-pattern-generator

Basically I would have all the cnc files ready to cut for the day with the matching patterns for the LaserShark galvo scanner to help with material loading/placement.  I would just call up each pattern for each part, nothing fancy changing live just a still pattern projection.  Would this work with a simple Rasp Pi and say the files loaded on a usb or memory card? 

I would maybe use something like the frame creation tool near the bottom of this page:
http://elm-chan.org/works/vlp/report_e.html

I only need to make one pattern frame per cnc program to load the material properly. 

I know this is kinda a weird question/request but any input would be appreciated.  The price on those professional laser pattern projectors is way out of my league and also I don't need it to be as precise.
Thanks,
-Max

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