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Author Topic: Having a small problem with mach3  (Read 9118 times)

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Re: Having a small problem with mach3
« Reply #10 on: November 12, 2008, 03:50:27 PM »




Some more, well that explains it. Now i know its not my machine..
Re: Having a small problem with mach3
« Reply #11 on: November 12, 2008, 10:32:35 PM »
anyone :D?
Re: Having a small problem with mach3
« Reply #12 on: November 12, 2008, 10:43:51 PM »
If you make changes to CV settings make sure you close Mach and reopen it. As it seems to have problems saving these settings mid session.
If mach is not staying tight to the tool path you either need to slow down or turn on CV dist tol. The value for this is part dependent. I would guess for your part size about 0.10" would be a good place to start. Again if you make any CV settings changes close and reopen mach.

Offline RICH

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Re: Having a small problem with mach3
« Reply #13 on: November 13, 2008, 07:27:53 AM »
Hmm.....depending on the corner radius, look ahead, and what needs to happen to keep velocity the path may be
automatiicaly changed.....not sure what i said is correct
rich

Offline Hood

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Re: Having a small problem with mach3
« Reply #14 on: November 13, 2008, 07:54:54 AM »
Not read through the rest of the post so if its already been said please forgive :) Ok for a test have a look in the code and see if there are any G64's if there are replace them with G61, also make sure there is a G61 before the first cut. If that cures your rounding then it shows that its a CV problem due to the acell of your particular machine and you will need to try and tune the CV settings to suit.
Hood
Re: Having a small problem with mach3
« Reply #15 on: November 20, 2008, 05:54:20 PM »
Sorry for the delay in followup. I appreciate your help. Anyhow I ran it again using suggested settings of cvangle to 35 and dist tolerance of .01 but still having issues. As you will see below the parts cut perfectly but it was choppy, feeds from 200IPM down to 25IPM at curves it didn't handle it how I would expect other than that it followed the toolpath perfectly.

I guess what I'm getting at is that I'm having a hard time finding a balance between acceptable constant velocity and necessary cv. I want it to go fast because the machine is designed to do so but the software skips the beat because the machine can't make those corners without either slowing down or cutting them. And the strange part of all of this is until now I have never had to play with CV settings, everything I have ever cut has been perfect; mach seems to always have compensated for corners and curves slowing down when necessary. Where am I going wrong with this?  Thanks again!




Offline RICH

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Re: Having a small problem with mach3
« Reply #16 on: November 20, 2008, 07:14:36 PM »
Understand you want to go fast, but I'm a slow poker who prefers accuracy, repeatability and reliability over speed.
So find a speed that gives you that then fool with the settings until cutting is achieved. Now bump the speed gradually
up until you find the max speed for what you are cutting and back off say 20% for that particular material. What you are cutting may require a slower speed. Again, if you were cutting using circular interpolation ( G2 / G3 ) instead of cutting small straight line segments it would not be jerky. Your motors would be singing to you.
RICH

Offline simpson36

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Re: Having a small problem with mach3
« Reply #17 on: November 21, 2008, 02:39:26 PM »
I don't know if this has any relation to your problem, but I've been evaluating Mach3 and I had exactly the same result you got; namely what appeared to be random deviations from the desired path . .

It did not occure in any programs that I wrote but did appear in any wizard programmed code.

Eventually I noticed that there was a pattern to it. The tool was turning WAY early like you do in your car if you were driving REALLY fast, and that led me to check into the feed rate, motor speed and accelleration settings.


I use feed per rev and the wizard put out IPM, so the wizard stuck the feed at say 50 in the code which is 50inches PER REVOLUTION in feed per rev. That's what was causing the tool to go off path in my case. I would not swear to it, but I don't think I got any errors . . . it just ran fine, but with the tool doing exactly what yours is doing.

In messing around trying to figure the problem out, I notuced that (if I am remebering right) that the accelleration set in the motor tuning also can cause the tool to meander is Mach thinks the motors need more time to accell decell than they really do.

So you might check your motor tuning settings and see if something has changed there.

Offline docltf

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Re: Having a small problem with mach3
« Reply #18 on: November 21, 2008, 04:16:34 PM »
try this setting