[SScnc]

I posted this in the CNC router section about a week ago and no one had an answer. I should have posted here to begin with...


The vid explains it, slow zone works on the Z axis perfect but the X and Y slow zones do not work at all. Anyone know what's causing this ?

Thanks!



[nomedia="http://www.youtube.com/watch?v=fuY-NEJqsik"]YouTube- noslo6.mpg[/nomedia]

I don't know why the youtube player screen won't work here on the Zone tonight ???

[jalessi]

SScnc,

Are you sure the Soft Max is set correctly,they may be set to long.

If it is wrong Mach3 never reaches the "Slow Zone" position.

Jeff...

[SScnc]

Hi Jeff, Yes, I think they are correct. Both axis will move to the 43 and 33 positions and of course to zero. And they don't even slow down for zero positions. And the axis do slam to a full stop at those positions.

Thanks,

Steve

[jalessi]

Steve,

Have you tried reducing the speed setting?

[SScnc]

I did reduce the speed from original settings and I think they are now at X= 20% and Y=50%. I'll try reducing it some more.

And thanks for the graphic too,

Steve

[jalessi]

Steve,

50% is extremely high , especially since your machine has very high rapid acceleration.

Jeff...

[ger21]

Also try increasing the length of the slow zone, just to see if it helps.

[SScnc]

Also try increasing the length of the slow zone, just to see if it helps.

Hi Ger, I had done that but I went back and tried various settings from 50 to 500K and nothing changed. I did make a mistake in my post, the slow zones work on the Z and the Y, it's just the X that it's not working properly on. The X is the only belt driven axis I have at this point, I did change the velocity of the X in motor tuning from 801 to 25 and then the slow zone worked. But 25 is way too slow for this machine.

So I'm guessing it must have something to do with my steps per inch, my Z is 25000 spi, the Y is set at 20000 spi and the X is 518.6721992 spi. But I really have no idea how to make it work.

Jeff, the 50% is of course for homing and the X (y and z too) home perfectly so I don't see that as a problem regarding the slow zone unless I'm missing something. Oh and just to clarify, in the video when the X suddenly stops at the soft limits, it's not hitting any physical stops, that's just the soft limits suddenly stopping it.

Any ideas ?

Thanks,

Steve

[jalessi]

Steve,

The speed setting is a function of the slow zone, try reducing it to 5% on the X axis.

Jeff...

[SScnc]

Steve,

The speed setting is a function of the slow zone, try reducing it to 5% on the X axis.

Jeff...

Oh okay, I did drop it to 10% this morning and no difference, I'll go out to the shop and try 5% and report back.

Thanks

[jalessi]

Steve,


After you change the speed setting make sure you click the "Save Settings" button otherwise the change you made may not take effect.

Jeff...

[SScnc]

Hi Jeff, I changed to 5% on the X in homing and limits and settings are saved. Still no slow zone on X. I also turned the feed rate on my pendant down to 15 IPM for the X and no slow zone at all. Just for the heck of it I made the slow zone at 1000000, no change. I know other guys have belt driven axis and I assume their slow zones work so I must have something wrong.

Thanks for the help so far,

Steve

[ger21]

Since it's a percentage of the 800ipm, I'd try 2-3%. But I think the problem is you don't have enough room to decelerate when you get to the slow zone.
Increase the distance to 6, and use 2%. If it works, fine tune the numbers to get something that works good for you.

What's the acceleration set to, btw?

[SScnc]

Okay ger, I set zone to 6 and 2% and no difference. The accel is at 17 for the X. Maybe I just need to find a compromise on the velocity (?)

Thanks,

Steve

EDIT: Well I'm completely out of ideas now, the only way I can get it to work at all is to slow the velocity down to barely a crawl and up the accel to a point that it's too high. I've changed every setting I can find except the steps per inch. I guess I'll have to live without the slow zone on the X for now unless you guys have any other ideas.

Thanks again for trying to help !

[kada]

I had he same problem. Due to the large inertia of axes, they can not just slow down and run into the frame of the machine. After I increased the Slow zone, the problem is solved.

[piccyman]

have you calibrated the steps/inch on each axis?