Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: rcrabb on January 07, 2007, 09:55:24 PM

Title: Rotational feedrate problem
Post by: rcrabb on January 07, 2007, 09:55:24 PM
I'm having a problem with with my feedrate on my rotational axis. I have .0001 in the rotational Dia DRO. The feed rate seems ok untill a line of Gcode has no Z move. Then the feedrate goes too high and my motors stall. If I enter the actual diameter of the piece in the DRO the feedrate stays constant for a while then ramps up periodicaly. What am I doing wrong here?
Title: Re: Rotational feedrate problem
Post by: Chaoticone on January 07, 2007, 10:08:51 PM
In config, toolpath, do you have your use diameter for feedrate checked?
Title: Re: Rotational feedrate problem
Post by: rcrabb on January 07, 2007, 10:10:27 PM
Yep, its checked
Title: Re: Rotational feedrate problem
Post by: Chaoticone on January 07, 2007, 10:15:46 PM
How about in config, slave axis. Are any axis slaved?
Title: Re: Rotational feedrate problem
Post by: rcrabb on January 07, 2007, 10:18:23 PM
Nothing slaved
Title: Re: Rotational feedrate problem
Post by: Chaoticone on January 07, 2007, 10:21:12 PM
I got to take a nap soon. Can you post your xml and the code with notes of where you are having problems? What version of Mach are you running? Mach 3 version 2.0.0??


Brett
Title: Re: Rotational feedrate problem
Post by: rcrabb on January 07, 2007, 10:31:01 PM
Mach Version 2.0.031.

I enter .0001 in the rotational diamenter DRO and the rotational feedrate is good untill a line code has no Z move.

If I enter a Diameter of 1.25 in the DRO the feedrate ramps up about every 20th line.
Title: Re: Rotational feedrate problem
Post by: Chaoticone on January 07, 2007, 10:55:01 PM
Forgive me, I will have to look closer in the morning. Are you running in single block or doing a feed hold while it is runnig this program? If so, try it running straight through with neither feed hold or single block. They had a few bugs in the past but I think they have been fixed.

Brett
Title: Re: Rotational feedrate problem
Post by: Brian Barker on January 08, 2007, 07:51:36 AM
Could you please post an example of the code that is giving you trouble ?
Thanks
Title: Re: Rotational feedrate problem
Post by: rcrabb on January 08, 2007, 08:18:56 AM
Brian,

Here is an example of the code giving me trouble.
Title: Re: Rotational feedrate problem
Post by: Brian Barker on January 08, 2007, 08:32:42 AM
So is it the A only moves that are the trouble ?
Title: Re: Rotational feedrate problem
Post by: rcrabb on January 08, 2007, 09:26:35 AM
Yes, A only moves. The rotational feedrate goes to high and stalls my motors.
Title: Re: Rotational feedrate problem
Post by: Brian Barker on January 08, 2007, 09:30:34 AM
Cool that will tell me where to look in the code... that is a section of code that had not been worked on in a ver long time...
Title: Re: Rotational feedrate problem
Post by: Chaoticone on January 08, 2007, 09:35:28 AM
Hey Rcrabb,
     I will load it in my machine pc sometime today. Does your a axis rapid jog without missing steps? I'm not seeing it on this PC. The a axis does vary, but from what I can tell, it should because you are using the diam. for feedrate and it seems consistent with a z move.


Brett
Title: Re: Rotational feedrate problem
Post by: rcrabb on January 08, 2007, 09:43:13 AM
Use the second file I posted (rotational test.nc)
Title: Re: Rotational feedrate problem
Post by: Chaoticone on January 08, 2007, 09:54:27 AM
You got it.

Brett
Title: Re: Rotational feedrate problem
Post by: Chaoticone on January 08, 2007, 10:30:22 AM
Hey Rcrabb,
   I have sent you a PM.


Brett
Title: Re: Rotational feedrate problem
Post by: Chaoticone on January 08, 2007, 10:57:19 AM
Hey Ryan,
    Here is a screen shoot of the check box we talked about.


Brett
Title: Re: Rotational feedrate problem
Post by: Brian Barker on January 08, 2007, 01:08:12 PM
I need you to do the following...

In MDI do a G01 Z.1 A 360 F80

then do a

G01 Z1.0 A.1 F80

and last G01 A360 F80

Tell me if you get an over speed on them.

Thanks


Title: Re: Rotational feedrate problem
Post by: rcrabb on January 08, 2007, 02:34:14 PM
I did your test and did not get an overspeed. I attached my XML file and a test file that has the overspeed problem. Watch the feedrate DRO when the code gets to line N400. It jumps from 20000 to about 25000.
Title: Re: Rotational feedrate problem
Post by: rcrabb on January 08, 2007, 11:06:12 PM
I got it working. It seems my A moves were absolute. I had to unselect Rot on 360. Now my code runs SMOOOOOOOTH. But now my A axis DRO doesn't show degrees.
Title: Re: Rotational feedrate problem
Post by: Chaoticone on January 08, 2007, 11:48:04 PM
HOOOOOOORAY!!!!!!
       Now you can rest good tonight. Glad you got it. I have been tied up with a customer tonight.
Have you tried screen designer 4? I think your dro can be set there.

Brett
Title: Re: Rotational feedrate problem
Post by: Brian Barker on January 09, 2007, 06:55:58 AM
Nice! I will still have to have a look at the XML and see if there is a way to get that workign better :)