Messages

11

General Mach Discussion / Re: Optical Registration Mark Reading With Mach3

« on: January 29, 2014, 10:04:59 AM »

Another question, I'm trying to wrap this around my head...if the distortion is non-linear how would one go about performing the scaling so that the modified toolpaths match the drawing.

Zund iCut and others somehow do this perfectly based on the registration markers alone but I'm having a hard time figuring out how if the distortion is non-linear.

12

General Mach Discussion / Re: Optical Registration Mark Reading With Mach3

« on: January 29, 2014, 08:11:51 AM »

Here is a thread relating to the laser cross hair pointer http://www.machsupport.com/forum/index.php/topic,10841.0.html

Tweakie.

Yea I already read that and it's certainly something I want to add.

A question though, would I absolutely need the laser pointer ?

I'm asking cause if I make a cross mark and zero the tool in the dead middle of it it should be accurate enough, is there a need for the pointer for this talk alone ?

I mean the zund has a dot laser pointed and I don't really need that much either, I can just lower the bit itself into the middle of the cross and that should do it or have I missed something ?

13

General Mach Discussion / Re: Optical Registration Mark Reading With Mach3

« on: January 29, 2014, 07:12:38 AM »

Guess it's time to start learning VB and figure out a way to implement this.

This is not a bad solution for now, in the future doing it with a visual camera system may be possible but for now this will do and is more than enough to keep my busy.

If anyone can point me in the right direction on how I would go about implementing this I would appreciate it.

14

General Mach Discussion / Re: Optical Registration Mark Reading With Mach3

« on: January 29, 2014, 06:10:52 AM »

A visual location method and local system rotate was discussed in a earlier thread http://www.machsupport.com/forum/index.php/topic,22932.0.html
It is not difficult nor expensive to implement.

Tweakie.

Thanks for the quick reply.

I'll explore it.

15

General Mach Discussion / Re: Optical Registration Mark Reading With Mach3

« on: January 29, 2014, 05:57:02 AM »

So I've been thinking.

Optics may be too big a bite for now but how about something like this:

http://www.youtube.com/watch?v=bSPeiQl2k10


One would print 4 (or so) cross-marks at each corner of the print to be cut, manually go to #1 and in the software sort of zero there, then go to #2 and "zero" there as well and doing so for all 4 of them. Now the software has a reference points compared to the original toolpaths and can rotate and scale it accordingly, just like in the Zund example above.

How hard would this be to implement ? It's a bit more tedious to do manually but it's alright.


On a different front I've also found a company in the Netherlands that offers a vision system:

http://cnccamera.nl/src-gen/products.html

I've sent them an email and hopefully their system will be in an acceptable price-range.

16

General Mach Discussion / Re: Replacing electronics on a CNC

« on: January 12, 2014, 11:23:22 AM »

I was hoping that you would make a reply Tweakie.

You are probably right but in this case I'd rather not invest too much money into this machine. We are about to buy a 3050x2050mm machine but would still like to keep this one operational cause it's more convenient for smaller jobs but I don't know how much life the steppers have in them left anyway and if they were to fail I wouldn't go through the trouble of replacing them.

17

General Mach Discussion / Re: Replacing electronics on a CNC

« on: January 12, 2014, 11:04:11 AM »

Dont have enough experience to help you but other members may chime in and help. The only thing I can say is do not buy from ebay the breakout board / drivers because you will need support for the connections and you will get non from China. Find a US vendor who is willing to support with all your questions and you will have lots of them since you are not familiar with electronics. Another item I can add is that the manuals which come with these items are almost useless to people with no experience so you will need tons of support.

Am not from the US and won't be able to get the electronics locally.

I'm used to figuring stuff out myself though, been like that pretty much with every machine I've ever bought including this CNC mill. Even when one gets service locally the people doing it don't have a clue what they're doing so you're on your own most of the time.

Thanks for taking the time to post, much appreciated.

18

General Mach Discussion / Replacing electronics on a CNC

« on: January 12, 2014, 09:57:06 AM »

Hey peeps,

I've done a lot of work on my small 1000x600mm CNC router these last few days and during that last stretch of work it started freaking out. All of a sudden the Y motor starts going into random directions I tell it to go forward and it goes forward, and backwards and backwards and forwards...After a bit of fiddling I take out the breakout board, figure out where that motor is connected and I see that the part where it's screwed in has been burning. Thankfully I got it working and managed to finish the job.

Another thing is, my little router was rated 2000mm/min by the manufacturer but I can only get it to run around 800mm/min consistently. At first it works fine but after a few minutes the motors start stalling. At first I assumed that the motors just couldn't handle it but now I have a new theory...since it is manufacturer rated for 2000mm and it can perform like that for a while before they start stalling AND since I am having electronics problems I am guessing that the electronics are near death. So I guess when I try to get it to run at 2000mm the electronics just can't deliver enough power to the motors consistently cause they're old and worn out.

So I've decided to beef up my CNC by:

- Replacing the breakout board
- Adding limit switches on X, Y, Z
- Adding an estop button
- Adding one of those probes for setting the z zero (toolsetter probes or what)
- Adding a pendant


Right, so what's the problem then ? Why am I opening this thread ?

Well...I don't know a lot about CNC electronics so I thought I'd question a higher authority instead of buying a bunch of stuff and finding it doesn't work.

At first I thought that i would only need to buy a breakout board and plug my CNC motors and the rest of the stuff in, since my current router only has a single board where everything is connected (everything being the motors since it doesn't have limit switches and the spindle is a router that's manually turned on).

But (thankfully) I then did a bit of research and think that I may need a driver for each of the motors. Is that the case ?

My Y and X motors are VEXTA 2 Phase motors, 2A each and the Z motor is 1.2A

I don't know the voltage of the steppers, does it matter ?

The whole premise seems simple enough, and please correct me if I'm wrong but from what I know...plug power from transformer to the new breakout board, plug drivers into breakout board, plug parallel cable into computer. Add the rest of the stuff (estop, probe, limits) into the breakout board and configure all the pins in Mach3. Am I missing something ?

I also haven't figured out where to buy the breakout board, drivers and limit switches. I've looked around ebay and found some stuff but I'm not sure if it's any good or if it will even work together:

http://www.ebay.com/itm/USB-5-Axis-CNC-Breakout-Board-Interface-Adapter-For-Stepper-Motor-Driver-/321133023129?pt=LH_DefaultDomain_0&hash=item4ac5050f99
http://www.ebay.com/itm/CNC-Single-Axis-TB6560-3-5A-Two-Phase-Hybrid-Stepper-Motor-Driver-Controller-/321170671199?pt=LH_DefaultDomain_0&hash=item4ac743865f


Would this work ?


EDIT:

Forgot to include images:

http://imgur.com/a/uJrWj

19

General Mach Discussion / Re: Optical Registration Mark Reading With Mach3

« on: January 12, 2014, 07:03:27 AM »

I don't have a programing background but how hard would it be to make a piece of software that would take a video, look for the registration markers based on the g-code (or dxf or whatever) and then compare their angle to the g-code and align to the g-code to what it saw ?

Because the machine’s camera is unlikely to be able to view the whole job in one frame and it would be a waste of machine hours scanning the total work area just looking for the markers my suggestion would be…

A software program (plugin) to view an on-screen display of the original artwork where pixel size versus steps per unit is known – using the mouse, the registration marker positions are located and stored, their position is then translated to the necessary X-Y co-ordinates for the machine to move the camera / machine head to each selected marker. The camera then centres each registration mark in turn or is used to determine the difference in the pixels position (not sure just how to do this yet but there must be a solution) and the difference between actual position and original image position of each marker is calculated. This data is then used to set the Mach3  X and Y scale factors (if necessary) and ‘local system rotate’.

It would be challenging project to do but, in my opinion, it is entirely possible.

Tweakie.

I'll do some research to see if there is anything similar in the "open" out there but I don't code so the chances of pulling this off at this point are slim.

Besides this isn't something that needs doing right now, we plan on using it on a new machine which we don't even have yet but I thought if I could figure it all out by the time we get the new machine I could have it implemented shortly afterwards and we could start using the system relatively quickly.

At this point I think it would be easier to just create the design with a + shaped reg mark, a decent amount of bleed, do the print and export that reg mark and an outline of the print to a dxf, handle it in the cam software, set the machine zero of the work in the middle of the + mark and then, possibly, use a pair of lasers to perfectly align the substrate so that the X and Y are straight. Then simply set the zeros in Mach3 to the middle of the + mark and that should be precise enough to get it to cut out properly.

The camera setup is certainly something to keep thinking about though, not giving up on it just yet but this is more realistic for now.

20

General Mach Discussion / Re: Optical Registration Mark Reading With Mach3

« on: January 07, 2014, 07:13:19 AM »

First of all thank you both for your replies.

I think that the simplest and fastest solution may be to add a certain amount of bleed to the print so that you have some more wiggle room but even then you don't want to go too deep into the bleed cause you want as little excess color around the print itself.

Anyway I think that having a pair of laser crosshairs on the CNC head would be the fastest solution. In that case I would just export the registration marker and an outline of the work piece to g-code and then when adding the workpiece to the CNC table I could use the laser crosshairs to position the workpiece at an perfect angle then I could just place the bit onto the middle of the registration marker, set that as the zeros and start routing.

Still having a camera system would be easier and faster.


I don't have a programing background but how hard would it be to make a piece of software that would take a video, look for the registration markers based on the g-code (or dxf or whatever) and then compare their angle to the g-code and align to the g-code to what it saw ?