we have a gantry machine that we setup with 2 switches hooked in series 
for each axis.  One is on the linear slide - one runs off the timing 
pully.  When we home - the machine runs until it closes the switch on 
the linear slide -  then because the switch are hooked in series - the 
switch that is activated by a tab on the timing pully is what emc sees 
as the home switch.  pretty darn accurate.

sam

On 11/24/2010 2:41 PM, Edward Bernard wrote:
> So the flag could be a something like a single hall sensor and magnet as 
> opposed
> to a quadrature encoder?
>
>
>
> ----- Original Message ----
> From: Kirk Wallace<[email protected]>
> To: Enhanced Machine Controller (EMC)<[email protected]>
> Sent: Wed, November 24, 2010 1:43:23 PM
> Subject: Re: [Emc-users] Index Basics, OT: leaving stepppers
>
> On Wed, 2010-11-24 at 10:46 -0800, Edward Bernard wrote:
>> What is a "screw flag". An encoder?
> An encoder index or a flag that allows one to reproduce the same
> position within .0005", or whatever the application calls for. I would
> not trust most home switch configurations by themselves. They should be
> ANDed with a sensor with a mechanical advantage, such as on the lead
> screw or axis motor shaft. The home switch gets you within one turn of
> the flag or index, sensing the flag gets you home.
>
> Currently, on my mill, I have markers on each axis. I jog each axis to
> line up the makers, then watch the hand wheels and jog to line up "0" on
> each dial, then I press home for each axis in AXIS. Using a home switch
> could replace the markers. Using a flag or index, could replace the
> dials, and allow EMC2 to automate the home sequence. When you know where
> your home is, you know where your fixtures and soft limits are.

------------------------------------------------------------------------------
Increase Visibility of Your 3D Game App & Earn a Chance To Win $500!
Tap into the largest installed PC base & get more eyes on your game by
optimizing for Intel(R) Graphics Technology. Get started today with the
Intel(R) Software Partner Program. Five $500 cash prizes are up for grabs.
http://p.sf.net/sfu/intelisp-dev2dev
_______________________________________________
Emc-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/emc-users

Reply via email to