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Auto stop on spindle overload.
« on: January 09, 2017, 04:59:55 PM »
Sometimes on my lathe I get a little over aggressive on my cuts and overload the spindle in which case the board trips and the spindle stops.  When that does happen a light bulb is lit and I have to manually flip the spindle direction off and on.  All good except that Mach doesn't know that the spindle stopped and continues to go merrily on its way with the rest of the GCode.  Ouch!

Query, I'm sure that I can wire to capture when that light is lit and use it as a signal to EStop Mach.  I assume that is the correct way to stop movement as quickly as possible.  But, since I have a tach, I was wondering though if I could use a brain that checked if the spindle was supposed to be turning and if wasn't, issue an EStop?  Thoughts?  Other ideas?

TIA

RT

Offline RICH

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Re: Auto stop on spindle overload.
« Reply #1 on: January 10, 2017, 06:51:58 AM »
It would be much better to know what you can and can't do with your lathe than creating something to address bad programing.
A few minutes of hobby time to do something when using CNC is nothing!

Just a thought,

RICH
Re: Auto stop on spindle overload.
« Reply #2 on: January 10, 2017, 07:02:19 AM »
So Rich...what you're saying is that limit switches are unnecessary?  ;^)

Just kidding.  All I do is hobby stuff,so point well taken.  Always trying to push the limits. Just the way my mind works.

Offline RICH

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Re: Auto stop on spindle overload.
« Reply #3 on: January 10, 2017, 07:33:19 AM »
Who needs limit switches? I don't have  one machine that uses them.  ???

RICH

Offline Davek0974

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Re: Auto stop on spindle overload.
« Reply #4 on: January 10, 2017, 09:37:31 AM »
I'm always of the school of thought that "if it can go wrong, it will" so i'm with the OP here and would certainly link a stop in to Mach somehow to stop ploughing the tool into a non-moving workpiece. No matter how good the users knowledge is, safety-nets to me are just basic machine design and should be fitted.

Just my 2p ;)
Re: Auto stop on spindle overload.
« Reply #5 on: October 23, 2017, 02:12:54 AM »
« Last Edit: October 23, 2017, 02:14:46 AM by zmajmr »

Offline Davek0974

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Re: Auto stop on spindle overload.
« Reply #6 on: October 23, 2017, 04:52:03 AM »
Nicely done I think.
Re: Auto stop on spindle overload.
« Reply #7 on: October 23, 2017, 05:29:38 AM »
Nicely done I think.


Hi, thx, need to upload part 2 and 3 where I show more detail what is inside of brains, I tested it and it works pretty good and for sure I know it will be useful at least to me :)

Offline RICH

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Re: Auto stop on spindle overload.
« Reply #8 on: October 23, 2017, 07:17:45 AM »
FWIW,

I believe one needs  to ask and then define what they are trying to protect.
There are many scenerios to consider. You can add all the protection, indications, whatever
and still trash the work, cause damage, or even personal injury.

The first step to safety is to invision it. The next step is to address the concern and provide protection
if even possible. Even redundantcy is not 100 %.

One way, is to avoid the problem in the first place. One can calulate HP requirements and
know before hand approx capabilites of a machine. Lots of research has been done in this area
over the years and most manufactures use the same basis for calculating stuff.

In industry evaluation is done from many different viewpoints. BUT........................
In industry it's all in terms of money / cost vrs investment ..............and that my friend is a fact!
Even loss of life is in terms of dollars in evaluations.

RICH

Offline Davek0974

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Re: Auto stop on spindle overload.
« Reply #9 on: October 23, 2017, 08:21:21 AM »
My main bugbear is when Mach starts running code but omits to start the spindle - i have asked about this and it seems its a known issue but rare and hard to replicate. Its great for busting milling tools though :(

I was think of looking at my spindle power and stopping the code if that reads zero and its about to issue a move.

Its something to do with the compiler, it throws a "complier error in M03" error message but just carries on going.