Newbie- Need Help With Setup

[compmedic]

I have a Zenbot Router with xylotex controller.
I need help setting up my table i think. My table Dimensions are 6x-8y-3z.
When i try to run the example emc2 file it says that it exceeds my travel.
I think my table is big enough to run the engraving.
I got the table set-up as follows:

start: end:
0.0 12.0 x
0.0 16.0y
0.0 4.0z


Thanks for any help.

Darren

[chester88]

I would bet it is the Z axis that is the problem. it should be a negative number
I can use a lathe as an example :
usually the end of the part that is FARTHEST from the chuck is Z zero and gets more negative the closer to the chuck you go.

I think the mil is similar Z zero would be when the table and head are the FARTHEST apart then Z goes negative as you they get closer to each other.

try setting z at -4 and 0

Someone else will come along a confirm this I'm sure.

[chester88]

Ok I thought about this more.

The machine limits are based on where your home 0 position is.

say home 0 for the X axis is in the middle of the travel.
you say your X is 12" long - then the correct number would be -6 and 6

So it's the signed (+ or -) distance on either side of home zero position.

[compmedic]

my x axis is only 6 inches
my y axis is 8 inches
my z axis is only 3 inches
I set it up like would in mach3 cuz i dont know how emc2 is set
So i set:
0 - 12
0 - 16
0 - 4
4 just to be safe

[vlmarshall]

Are you setting your limits for more travel than your machine has?
Where does your machine table home, at the extreme positive, or negative end of travel?

[compmedic]

Ummi dont believe so.
umm maybe i should of mentioned i dont have any home or limit switches.
So i use 0.0 as soft home u could say. Not for sure.
Should they be set to like:
-6 and 6
-8 and 8
-3 and 3

[cyclestart]

Even on a machine without switches you must establish a HOME zero position . The [dot]ini file (likely mymill.ini) decides where these are positioned. On my machine I chose to locate these at the extreme ends of the travel, I just find it less confusing that way. You would prefer HOME to be the center of travel ? That can also be done.

BUT you have given the machine a larger work envelope than it has in reality. I think the real problem is you are misunderstanding the relationship between machine zero position and workpiece zero position. If not, you are misunderstanding how to establish a HOME in .ini. There is also part program zero to be considered. The emc text program is lower left 0,0,0 iirc.

It's possible to tell emc the machine has a thousand inches of travel and still get an "exceeds travel" error. Emc has good manuals. Sorry if that comes across as "rtfm " but it's time well spent. This wiki entry might also help.
http://wiki.linuxcnc.org/cgi-bin/emc...rdinateSystems

edit/ Is it safe to assume you setup the machine using stepconf ? Whatever you called the machine (mymill is default), There will be a file called 'thatname'.ini in your emc2 directory. Open that text file and paste the information under [Axis 0] [Axis 1] and [Axis 2] in your next post.

[compmedic]

I have been trying to tell emc the home postion is zero.
All the way forward and all the way left.
I have been reading the manual but i will try to go through it again.
Just hope i set my table travel right.

Thanks.

[Triggerdog]

Hello,
I just started using Emc2 and I really like it. I am using the Ubuntu 8.04 install. I had similar "problems" but I didn't have the machine setup correctly in the "EMC2 Stepconf Wizard". Even correctly set up it will give a warning if you over travel which is great because it doesn't allow you to crash your machine. Also be aware that you might have a tool path that "undertravels" below 0. If you have your z axis travel set from 0 to 6 inches for example and try to run the z to -.05 it will give a warning and not run. I am running the Axis 2.2.8 an it comes up the the EMC2 Axis gcode engraving. You should see a red line box that shows the work area, if your toolpaths are outside that then it will error. I hope that helps, I have a sherline mill with xylotex drives and it works well with EMC2 so far.

[vlmarshall]

Originally Posted by Triggerdog I have a sherline mill with xylotex drives and it works well with EMC2 so far.

I have the same setup, I just installed EMC2 a few weeks ago, and I'm really enjoying it.

[chester88]

Ok the other related possible problem is you are trying to run the program while using the 'Machine coordinate system'
Meaning after you start your machine and home it (either with switches are by pushing the home button) you have established 'Machine coordinates'- these can not be changed. (on a side note G53 calls use this coordinate system eg. G53 GX 0Y 0Z 0 puts you at the 'Machine coordinate' zero points for X Y Z -probably where you homed at regardless of any other coordinate system being used)
What you need to do then is establish a coordinate system based from the part to be machined - The part origin needs to be established.
EMC has eight g codes that keep track of part origins (or work offsets as EMC calls them) G54 55 56 57 58 59 59.1 59.2

In AXIS "touch-off" is used to set the origin.
One way is to physically move the cutter to where the part program is expecting X Y Z 0 is and then "touch_off" entering 0 for each axis (X Y Z).
After that when you are using G54 coordinates system and you enter G0 X0 Y0 Z0 the machine will move to that spot.

I skipped some details here (I haven't actually programmed a CNC mill...) but that will get you thinking - keep looking at the manual too and ask some more questions.

[compmedic]

Is there a way to take screenshots in EMC2?
If there is then i will take one and show what im seeing.
If my X axis is 6" of table travel then my settings should be set-up as -3 and 3, right?
Im still using the manuals but they dont always tell ya what u need to know.