Re: EMC ini file questions.

[Robin Szemeti <lists-at-redpoint.org.uk>]

On Tuesday 29 April 2003 19:20, Jon Elson wrote:

> > MAX_VELOCITY = 1.2 ??????????????
>
> If you have defined the user units to be 0.03937xxxxx, your "user units"
> are inches.  If you've set them to be 1.00000, then your user unit is mm.
> MAX_VELOCITY is that many user units per **SECOND**.  So, if
> your units are inhes, the above setting is 1.2 IPS, or 72 IPM (a more
> familiar unit for machinists.)

This is something that has been bugging me with EMC for a while. 

That setting in my opinion shuold always be 1 ... 1 user unit .... then you 
should be able to specify some ALTERNATE mulipliers for the dispaly/control 
section ... but the machine itself is still working in its 'units' whatever 
they may be.

Say I want the machine to work in metres [1] .. can I set the units to be 1? 
after all its just 1 user unit (could be mm, cm, etc etc who cares, its just 
1 'user unit' ) why cant I use inches and set it as 1 ? after all so long as 
it goes from 0 to 1 when I ask it to, the machine has no way of knowing 
whether that 1mm or 1 inch in the real world ...  then the max veleocity is 
in metres per second, accelleration is in metres per second etc, 

It would make things a lot simpler if that setting was done away with and 
replaced by 

ALTERNATE_1 = 1000 (ie mm)
ALTERNATE_2= 100 (ie cm) etc
ALTERNATE_3 = 39.6 (ie inches) 

then I could set my machine up in metres (or whatever) and choose between 
some alternate display/command formats as required 

I'm lost as to why I would set the core units to be anyting other than '1' 
...  you see my problems arise when I started to build a large plasma cutter 
.. the number of steps per mm is 2 (roughly) .. when you get into this sort 
of territory it makes much more sense to use metres as your core unit (after 
all thats what the cutting speeds are quoted in) and just select an alternate 
display muliplier ... very strange things seem to happen in EMC when you 
start asking for machines with tiny steps/mm ( the accel/decel seems to start 
to go a bit lumpy) .. so for me at any rate working with mm as my base unit 
is not an option ... 

-- 
Robin Szemeti

Redpoint Consulting Limited
Real Solutions For A Virtual World