Hi

Some time ago I asked in this list what would be needed to
accomplish this tandem axis setup with EMC, I was hoping
it is already implemented and I would just need to set it
up correctly. Finally I decided to do it with "some" HAL
component. So far I did not start this task yet, because
there are still other issues with my machine and i did not
have too much time lately.
http://osdir.com/ml/linux.distributions.emc.user/2007-01/msg00180.html

I am a software developer however, and I'd be willing to
do what I can to make this work. Since I don't know EMC
code, I can't decide what is the best way to implement
this thing in EMC2.

The main problems/requirements are:
- Homing, Both axes have to move together to the homing point
  of each axis. An offset has to be introduced (homing point gap).
- Normal mode: both axes show as one axis in the gui. One is
  the master and gives the position feedback, the other follows
  at best effort. 2 independent position loops. (This can probably
  be done in HAL, so only homing is the hot spot)
- After Crash setup - Both axes show as independent axis
  (This can probably be achieved by creating 2 .ini files
  and if the axes have to be moved independent this 2nd
  setup can be opened in emc2)

That's just what I remember for now. Would have to think
about it more thorowly ...

Does anyone know how this homing problem could me implemented
most elegantly?

regards
Marc


Am Samstag, den 05.05.2007, 11:15 -0500 schrieb Jeff Epler:
> On Fri, May 04, 2007 at 11:49:22PM -0500, Jon Elson wrote:
> > Has anyone set up tandem axes in EMC2?  Getting two servo axes 
> > to run in parallel isn't too hard to do in hal, although what 
> > you do with two following errors is something to consider.
> 
> There is a tracker item for this feature request:
> http://sourceforge.net/tracker/index.php?func=detail&aid=1075625&group_id=6744&atid=356744
> 
> I don't think anyone is sure of all the things that need to be done
> before a gantry/tandem machine will work well under emc.
> 
> You mention having two following errors, but I think that's solved by
> gantrykins (because each joint has its own following error)--however,
> feedback position is still a problem (which joint position do you use
> for the cartesian actual position?).   (Also, gantrykins isn't a part of
> emc yet, not even in the cvs version--there's just the code from
> axis.unpy.net)
> 
> Since the homing code I suggest hasn't been implemented yet, it's
> unknown whether it will actually be good enough homing for a gantry
> machine.
> 
> There are the GUI problems for 4-axis, 3-joint machines.
> 
> And then there are the problems we haven't even considered yet...  what
> is really needed is a developer with such a machine and the desire to
> make it work.
> 
> Jeff
> 
> -------------------------------------------------------------------------
> This SF.net email is sponsored by DB2 Express
> Download DB2 Express C - the FREE version of DB2 express and take
> control of your XML. No limits. Just data. Click to get it now.
> http://sourceforge.net/powerbar/db2/
> _______________________________________________
> Emc-users mailing list
> [email protected]
> https://lists.sourceforge.net/lists/listinfo/emc-users


-------------------------------------------------------------------------
This SF.net email is sponsored by DB2 Express
Download DB2 Express C - the FREE version of DB2 express and take
control of your XML. No limits. Just data. Click to get it now.
http://sourceforge.net/powerbar/db2/
_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users

Reply via email to