Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: Larry on March 08, 2006, 09:17:30 PM

Title: Homing in Mach 3
Post by: Larry on March 08, 2006, 09:17:30 PM

I've been using Mach 2 successfully, well ... that's exagerating since I'm a beginner, but everything seems to work as I expect it on Mach 2.  Anyway, when I switched to Mach 3, the homing function no longer works correctly.  The axes drive to the home switches, stop and reverse as normal, but they do not back off far enough to clear the switches.  Is there a configuration item I've missed?  The axes need to back off just a little farther to clear the switch.  I thought Mach 3 reversed and ran till the switches open -- true?  If that's the case, why isn't mine clearing the switch?  In diagnostics mode, the LEDs stay lit continuously once the axis reaches home.

-Larry

Title: Re: Homing in Mach 3
Post by: Brian Barker on March 09, 2006, 08:08:15 PM

So if I understand what you are saying I think you need to add some debounce... OR the other problem that you may be having is you need to put .1 in the Home Off (Under Config/ Homing and Limits)

That may not do it but it is a good place to start.

Title: Re: Homing in Mach 3
Post by: sshneider on March 10, 2006, 01:12:29 AM

Hey Brian,

What does "debounce" mean and how does one add it?

Title: Re: Homing in Mach 3
Post by: Larry on March 10, 2006, 06:53:59 AM

Thanks -- I didn't see the Home Off parameter you mentioned -- I'll look for it. That's probably my problem.

My switches already have debouce circuitry. They are optical switches and I''ve looked at them with a O-scope and they are very clean.  Their output is a 7400 series digital gate with nice clean transitions.

For sshneider, bounce refers to the rapid variation in the elctrical signal coming off a switch.  Mechanical switches are particularly sucesptible to bouce.  As they open, the electrical signal through the contacts essentially chatters on/off very fast as the switch contacts separate -- then will clean up and go hi or low (depending on how the switch is wired).  If the computer interface is fast enough it will see these fast chattering signals and may react before the switch is fully open which can lead to false readings.  There are several ways to debounce a circuit.  If you need some schematics, let me know and I can email you some info.

-Larry

Title: Re: Homing in Mach 3
Post by: Brian Barker on March 10, 2006, 07:59:58 AM

This is on the Home/Limits page:

Title: Re: Homing in Mach 3
Post by: sshneider on March 10, 2006, 12:04:40 PM

Larry, Thanks for the info.  The more I read & learn, the more I realize how much I have to learn.  I feel like Orville Wright walking into the cockpit of a space shuttle and I'm a bit jealous of most of you dudes who are so friggin' profecient at this stuff.  Anyway... I'd love to see a schematic- can you email to slshneider@hotmail.com please.

Thanks!

Title: Re: Homing in Mach 3
Post by: ger21 on March 10, 2006, 12:22:27 PM

Quote from: sshneider on March 10, 2006, 01:12:29 AM

Hey Brian,

What does "debounce" mean and how does one add it?

It's in either Config>Logic or Config>State

Title: Re: Homing in Mach 3
Post by: Larry on March 10, 2006, 08:45:39 PM

Brian,  Thanks for the info -- I can't believe I missed it!  I put in 0.1 and it works perfectly. :)

sshneider, I'd be happy to send you schematics for debouce but you may not a ned hardware solution.  I didn't know MACH 3 had a software debounce function.  Go to the CONFIG menu item, then to LOGIC and enter a debouce value of ~100 or 200.  See if that solves your problem.  If not, please send me a note at LDB20151@yahoo.com and I'll send the schematics.

Good luck!

Title: Re: Homing in Mach 3
Post by: sshneider on March 10, 2006, 09:33:54 PM

DUDES!!!

That fixed my problem (putting 100 in the debounce box)!  Thanks again (and again and again and again and again!!!)

Sid

Title: Re: Homing in Mach 3
Post by: Brian Barker on March 11, 2006, 09:50:37 AM

Nice got two in one shot!

Title: Re: Homing in Mach 3 (Help please)
Post by: catheic on April 05, 2006, 04:05:08 AM

i can't home my machine too. and my axes are reversed. my z for example, it should start 0 from the top going negative downwards. right now, it's reversed. even if i click "reverse" it doesn't work...and more thing for instance i already reached the lowest my max z can travel, how do i bring it back up?

here are the screen shots of my configs

Title: Re: Homing in Mach 3
Post by: sshneider on April 05, 2006, 08:09:57 AM

Dude,

I am no expert but it sounds like you are on the wrong settings page.  Look under the config menu for the "Homing/limits" section.  Try the Home Negative and reversed check box there.  It probably would be good to also watch the video about homing/limits that is on the Artsoft website IMHO.

Good Luck!
Sid

Title: Re: Homing in Mach 3
Post by: catheic on April 05, 2006, 10:31:49 AM

hi Sid,
thank you for your reply.

i tried that and no luck. i did clicked reversed and home negative. i will try again tomorrow morning. thanks again bud!

 :)

Title: Re: Homing in Mach 3
Post by: Brian Barker on April 05, 2006, 10:31:59 AM

It sound like the Dir pin is not changing... If you jog the Z can you move it up and down?

Title: Re: Homing in Mach 3
Post by: catheic on April 06, 2006, 02:36:20 AM

i am jogging Z using the reference z button. now when i do that it doesnt move at all. it says one or more home switches  are active . please fix then home.
wahhh i am getting frustrated please help. i am using MAXPATH 42.. its a CL.

thanks so much for your help!

Cathei

Title: Re: Homing in Mach 3
Post by: Brian Barker on April 06, 2006, 09:05:35 AM

Is that computer hooked to the internet? I may be able to do some support with MSN messanger