Messages

1

General Mach Discussion / Limit tripped but nowhere near switch?

« on: September 13, 2019, 01:41:41 AM »

I was machining some mild steel yesterday and the limit kept tripping however I was in the center of the table with no switch anywhere close.

Does mach3 or perhaps the control board have a builtin feature where the limit will trip if the tool encounters too much resistance? Maybe as a feature to prevent damage to the machine when you crash the tool into something you cant cut?

I assumed this was the case because the machine works great everywhere else except when I was trying to use the side of the mill to cut with, and there and only there did the limit keep tripping.

fyi I have a C10 breakout board.

If this is a feature what is it called?

THanks!

2

General Mach Discussion / Re: How to make limit only trigger in one direction?

« on: February 13, 2019, 09:00:59 PM »

Then why does mach have the ability to put both switches on different pins if it doesnt know or care which way it was going before triggering?

Why not just have one pin for (+/-) and one for home?

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General Mach Discussion / Re: How to make limit only trigger in one direction?

« on: February 12, 2019, 10:09:54 AM »

Thank you for the detailed answer!

It is a C10 controller card - https://cnc4pc.com/c10-bi-directional-parallel-port-interface-card.html, perhaps this is the culprit?

So why then, if I only have *one* limit switch set up (either z++ or z--) does the machine halt when I depress the switch regardless of what direction it is traveling? If the head is jogging (--) and I hit the switch it stops; if the head is jogging (++) and I hit the switch it stops. Why does it do that?

4

General Mach Discussion / Why are x++ and x-- separate?

« on: February 11, 2019, 05:07:00 PM »

Even if you have a separate limit switch set to both x++ and x--, triggering either one will prevent you from moving again in the opposite direction from the direction that was triggered.

Shouldn't there be a way that mach knows which direction it was moving when it triggered the limit, and then allow you to move in the opposite direction without triggering again? otherwise whats the point for having the option to have both inputs?

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General Mach Discussion / Re: How to make limit only trigger in one direction?

« on: February 11, 2019, 04:59:18 PM »

Fine, everyone please ignore the first "reply", that was actually supposed to be a separate post. Ill re-post that one.

Regarding the original question that MN300 replied to- so youre telling me that it is normal for every time a limit triggers that you must hit reset twice, as the limit is supposed to trigger again while the physical switch contacts are opening?

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General Mach Discussion / Re: How to make limit only trigger in one direction?

« on: February 11, 2019, 04:14:16 PM »

I specifically made two separate posts on purpose because they are different questions. Merging them for me just makes it so much more confusing. Asking multiple questions in a forum post is always a bad idea, and usually resulting in only one being answered. And of course thats exactly what happened and now the last question didnt even get addressed.

Anyway- why does mach have a separate line for z++ and z-- if they both do the same thing then?

7

General Mach Discussion / Limit triggering twice? & Mach not knowing which direction triggered limit?

« on: February 09, 2019, 06:35:33 AM »

So when I trigger the limit I have the auto limit override set so all I have to do is hit reset, but then as I try to move off the switch the limit will trigger again because the button is still technically depressed. I must reset a second time before I can move off the switch.

I'm sure there is a way to fix this, since this seems like it would be a very common issue. If someone could enlighten me I would greatly appreciate it.

But also... shouldn't there be a way that mach knows which direction it was moving when it triggered the limit, and then allow you to move in the opposite direction without triggering again, since most people have both directions wired to the same switch?

Thanks!

8

General Mach Discussion / How to make limit only trigger in one direction?

« on: February 09, 2019, 06:28:27 AM »

I have the z-- limit set to pin 13 and the z++ limit is NOT set to that pin; the switch on pin 13 will trigger when moving in the negative direction as it should, but then after I hit reset and try to move the opposite way the limit will trigger once more as the switch is opening.

So how do I make the z-- limit switch only work when the Z axis is moving in the negative direction?

Thanks!