Re: new

[Ray Henry <rehenry-at-up.net>]

AJ

Welcome

Will you need a line follower like you have with the existing table or can 
your shapes all be done with cad or hand written g-code?  

I have the rough makings of a shape selection Tcl/Tk script for EMC.  It 
works a bit like the Linde systems that are popular around the US.  Select 
a shape, enter dimensions, orient, repeat and it creates the g-code to 
produce the parts.  Burn through can easily be handled with a dwell.   

There is a user that built one of these tables that needed instant on for 
his cutting device.  The EMC code was hacked to provide this signal through 
the parallel port.  If you do not need instant on, you can easily use the 
spindle on signal or one of the coolant signals.

Hope this helps

Ray   


On Sunday 14 April 2002 11:48 am, you wrote:
> Hi AJ Hettema
>
> A couple of links to get you going :-
> http://www.ktmarketing.com/faq.html
> http://206.19.206.56/
>
> Most certainly EMC can be used with encoder feedback with both servo and
> stepper drives. The resolution is only limited by the encoders fitted -
> If you used some of the high end linear scales, sub-micron resolution is
> possible. It is unlikely that your machine tool would be able to position
> to this sort of accuracy, and for a plasma cutter, it is not necessary.
> Standard 20 micron scales will give you 0.005mm, and using cheap rotary
> encoders on the end of the feed screws will still give you better than
> 0.1mm accuracy.
>
> There are a few papers on the usdigital.com web site that lightly cover
> the principals of encoder technology.
>
> Regards, Paul.
>
> On Sunday 14 April 2002 16:30, AJ Hettema wrote:
> > I think we can manage it to build such a machine with the documents we
> > have on cnc, and the EMC-software (ofcourse we need to feed it with
> > nc-code, but that's not such a big problem). What we would like to know
> > is, is it possible to build a EMC-machine that's controlling
> > servomotors and has something like feedback from the X and Y axis about
> > posistion. Or are servomotors accurate enough to reach a 0.1 mm
> > accuracy??? We couldn't find a document which describe's the use of
> > encoders to give the exact position of the X or Y axis.