Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: sn96 on January 24, 2011, 07:59:42 PM

Title: Softlimit settings
Post by: sn96 on January 24, 2011, 07:59:42 PM
Hello guys,

I have been playing with Mach3 trying to familiarize myself with the various menus and settings. There's a lot of settings! Anyway, In the motor home/soft limits dialog window it says "entries are in setup units". My units are set to inches but it appears that it is asking for mm values? It has to be mm because 100.00" would be over 8 feet long! that’s one huge milling table!
Title: Re: Softlimit settings
Post by: ger21 on January 24, 2011, 08:53:04 PM
or an average sized router.
Title: Re: Softlimit settings
Post by: Overloaded on January 24, 2011, 09:14:46 PM
Dont let the big default numbers confuse you Mike. Units are units, just set them to the extents of your machine.
Imagine a 10 foot router ... setup in MM. That would be 3048 !
Title: Re: Softlimit settings
Post by: sn96 on January 24, 2011, 10:37:31 PM
Ok I'm confused with the Z max settings. I keep getting softlimit errors that says "safe-z ignored, Z already higher than safe Z setting." When I try to start the program anyway, I get a pop-up that says "Soft limit warning.. continue? Yes /No" If I click yes, I get this error again "safe-z ignored, Z already higher than safe Z setting."

Here is a screen shot of my settings:

(http://i627.photobucket.com/albums/tt358/botwire/softlimits.png)

I have tried everything I tried swapping values clicking on reversed, home negative, larger values etc..

I tired the following:

MAX     MIN
5.00     0
0          5.00
5.00     -5.00
-5.00    0

Now I am completely confused. None of these settings seem to work. My Z has about a 5" travel.
 



Title: Re: Softlimit settings
Post by: Hood on January 25, 2011, 02:14:09 AM
Try with a  Z Max of 0 and Z Min of -5

Hood
Title: Re: Softlimit settings
Post by: angel tech on January 25, 2011, 05:40:17 AM
don't worry about the "100" setting, that's just a default figure. Are you homing before you set the soft limits.
Title: Re: Softlimit settings
Post by: angel tech on January 25, 2011, 05:41:52 AM
also your home speed is a bit high at 100%, i would normally not go above 30%
Title: Re: Softlimit settings
Post by: sn96 on January 25, 2011, 09:54:47 AM
Try with a  Z Max of 0 and Z Min of -5

Hood

I think I tried this but I will try it again to see.
Title: Re: Softlimit settings
Post by: Hood on January 25, 2011, 10:05:12 AM
Make sure its that way round, ie the Max is the Zero and Min is a negative value equal to your travel.
Hood
Title: Re: Softlimit settings
Post by: sn96 on January 25, 2011, 11:31:36 AM
Make sure its that way round, ie the Max is the Zero and Min is a negative value equal to your travel.
Hood

Thanks for your help I really appreciate it.

I think I never tried those values to be honest. I did seem to have partial success when I set the Z limits to max 5.00 min -5.00, at least the soft limit errors went away, so it makes sense that max 0.00  min -5.00 would work. The problem I had with max 5.00 and min -5.00 was the zeroing. I wanted it to zero at 0 and not any other value.

I'm at work so I won't be able to try this until tonight. Bummer!
Title: Re: Softlimit settings
Post by: sn96 on January 25, 2011, 08:36:45 PM
Well I tired setting Max Z @ 0 and Min Z @ -5.00 with no luck. I was not able to turn on softlimits without errors and I was not able to run the program. The spindle line shows it going through the part in fact. The only thing that seems to work half way are these values:

Z Max 5.00 and Z Min 0

I still get soft limit errors but I can at least run the program, jog etc. I just keep getting an annoying Bleep! telling me there is a soft limit error. Its hard to know whats going on without it connected to any motors. Perhaps when I get my steppers connected I can get a better idea of what's going on. If I could find someone who has a Sherline mill, I would like to see what values they have as well as if they have reversed checked or not.

Safe Z is another confusing factor. It seems as though I can jog regardless the height of my spindle.
Title: Re: Softlimit settings
Post by: ger21 on January 25, 2011, 08:53:50 PM
To use Softlimits correctly, you really need to home the machine first, to get a reference position for the softlimits. If you home to the top of the Z axis, which is typical, then Z max=0, an Z min= some value less than 0.

Since you aren't actually running a machine, if you want to play with softlimits, you need to pay particular attention to the axis DRO's, and make sure that the position the"machine" is in would be valid. Sounds like you are jogging outside of what the actual limits should be.

Safe Z doesn't restrict movement. It's a feature to lift the spindle to a safe height to prevent the tool from hitting clamps or other things.
Title: Re: Softlimit settings
Post by: RICH on January 26, 2011, 06:02:51 AM
May be of value.
http://www.machsupport.com/forum/index.php/topic,11409.msg72346.html#msg72346

RICH
Title: Re: Softlimit settings
Post by: sn96 on January 26, 2011, 12:42:04 PM
Thanks guys, I really appreciate all the help.

Rich, I downloaded and printed out the PDF file and it has really helped me to make sense of it all. It really is quite simple, but after thoroughly confusing myself messing around with so many things, I really need to stop and think about what I'm doing.

Part of my problem was not zeroing the machine, so things were getting out of wack combined with improper values, and in some cases I had the motors reversed only to add to the chaos.  ;D Your directions should get me back on track.

Thanks!
Title: Re: Softlimit settings
Post by: sn96 on January 26, 2011, 07:22:23 PM
Success! The settings Rich provided did the trick. Mach now behaves as expected. I have a new question however. When I click Cycle Stop, the Z goes to zero as it should, but when I click Cycle Start again according to the DRO, Z remains on Zero instead of going back down to resume cutting at the desired depth. Do you have to manually set the Z depth before hitting cycle start again?
Title: Re: Softlimit settings
Post by: ger21 on January 26, 2011, 07:34:25 PM
First, if you plan on resuming, you should only use Stop after the using Feedhold and waiting until movement stops. If you click Stop while the machine is moving, it will lose position.

If you want to resume, it will do exactly what the current line of gcode tells it to. Mach3 has no memory of what it was doing.

A better option may be to use Run From Here.