Author Topic: Question about Homing Offset feature in Mach 3  (Read 3085 times)

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Offline edclayton

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Question about Homing Offset feature in Mach 3
« on: October 28, 2015, 02:21:41 PM »
Under the motor home and soft limits menu in Mach 3 there is a place to put in values for homing offsets.
I tried putting in two different values there for my X and Y axis home switches. I used 1.000 and 0.250 on both switches for two different checks. Then I told those axis to go to their homes. I did not see the motors come back way from the switches on those two axis any differently than before I changed them from their default settings of 0.000 and did a Ref Y or a Ref Z to home my gantry in those axis.
Someone I know told me that this feature used to work like that for home but now it does not work anymore. If that is what this setting is for it did not work for me either. Is this a bug or no longer valid or is this setting for some other function?
Cheers,
Ed

Offline Overloaded

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Re: Question about Homing Offset feature in Mach 3
« Reply #1 on: October 28, 2015, 02:48:35 PM »
From Hood in an earlier post:

Home Off , often people think it means the distance the axis will back off the home switch during homing but that is not the case. Home Off is actually short for Home Offset. What that means is when you home the machine coords of Mach will be set to the value you have in the Home Off entry.
Normally you will have 0 in there however if you home to the positive end of the axis then you would enter the distance the home switch is away from normal machine zero, ie fully negative. What would happen in that case is when you home machine coords would be set to the Home Off value and thus Mach knows Machine Coords Zero is at the opposite end of the axis.
Another situation where you would use Home Off is if you have separate home switches and they are inboard a bit from your limit switch, say for example your limits are at the extent of the axis but your home switch is 50mm inboard, you would then set a Home Off value of 50. When you homed the machine coords would be set to 50 and thus Mach would know it has a further 50mm of travel in the negative direction before it reaches the true machine zero (limit switch)

Hood


Regards,
Russ

Offline edclayton

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Re: Question about Homing Offset feature in Mach 3
« Reply #2 on: October 28, 2015, 05:12:38 PM »
Thanks for the clarification about this feature. I was wondering if it might have been for a different use than what I originally was thinking. I will pass this info on to my friend on spiderplasma.com as well. This still might be useful for me because that's the configuration I have, limit switches beyond the home switches on the Y axis anyway. And probably soon to be on my X axis as well.
  8)

Offline RICH

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Re: Question about Homing Offset feature in Mach 3
« Reply #3 on: October 28, 2015, 06:01:09 PM »
Quote
for a different use than what I originally was thinking

That is the problem usually in that a lot of folks have some pre-conceived idea about what things are for, how they work, or how they think it should work.
A manual is only used to get something higher off the desk and is not to be read or studied.

BUT

Sometimes it is a real bear to figure out what's what from the manual without a total read / understanding of it.

I also fall into the " a lot folks" bunch. Guess I am a slow leaner, don't remember stuff, and don't take notes like the smart, wealthy, young, handsome,
well educated, refined, gentleman Russ!  ::)

RICH

Offline BR549

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Re: Question about Homing Offset feature in Mach 3
« Reply #4 on: October 28, 2015, 07:57:20 PM »
DANG I thought you were talking about me right up to the last word,  "RUSS".

 (;-) TP

Offline Overloaded

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Re: Question about Homing Offset feature in Mach 3
« Reply #5 on: October 28, 2015, 07:59:18 PM »
Nice to know there is another Russ runnin' round.
Cause I ain't none of that.

I just copy and paste. :)

(dim, poor, tique-ish, homely, gragiated w/Jethro and the only thing refined here is the liquor) Russ.   ;D

Offline edclayton

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Re: Question about Homing Offset feature in Mach 3
« Reply #6 on: October 28, 2015, 08:55:56 PM »
I confess I have not read the whole manual yet. I started to read it yesterday. So far I made it to page 55 or so. Its tough (for me anyway) trying to learn G code, Mach 3, inkscape and Sheetcam all at the same time. Not to mention all the manuals from CandCNC for the electronics. Its all kind of overwhelming but slowly but surely between all of them and all the kind folks out here on the various forums and the guys at CandCNC I am learning quite a lot pretty quickly. I'm just not as organized about it all as I would like to be. Mainly I just cant wait until I can finally successfully get this system configured at can start cutting out some stuff from some sheets of metal. After all isn't that what its all about.

Offline Overloaded

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Re: Question about Homing Offset feature in Mach 3
« Reply #7 on: October 29, 2015, 08:31:56 AM »
The manuals are good, but an equally powerful resource is the forum search utility.
Just put in "home off" and gads of info is at your fingertips. Including what I pasted in from Hood.

Russ

Offline edclayton

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Re: Question about Homing Offset feature in Mach 3
« Reply #8 on: October 29, 2015, 09:35:34 AM »
The manuals are good, but an equally powerful resource is the forum search utility.
Just put in "home off" and gads of info is at your fingertips. Including what I pasted in from Hood.

Russ

Thanks. I will try that out.
 Russ