Hello Guest it is July 07, 2020, 12:14:22 AM

Author Topic: Feed Rates Not Same as Gcode  (Read 2442 times)

0 Members and 1 Guest are viewing this topic.

Offline MattJ

*
  •  22 22
    • View Profile
Feed Rates Not Same as Gcode
« on: May 26, 2011, 05:29:24 PM »
Hello Anybody/Everybody,
My name is Matt and I have a problem, and no, an ointment won't cure it!
I am running a job and the feeds are considerably less than programmed.
I know it is something I am not doing right and I have tried to look for a solution.
Background...I import a DXF into Dolphin Cam which worked great.
Used a Mach 3 Inc post processor, that works fine.
My feed rate is programmed at 100ip. I bring the job into Mach 3 and it looks fine
tool paths are OK. I then cycle the job and the feed rates are about 1/3.
I did a test with a circle wizard and that worked fine.
I'll try to attach my xml if I can figure out how to.
Thanks in advance! I type about 3 words per minute, so if I left out anything,
let me know!

Offline RICH

*
  • *
  •  7,410 7,410
    • View Profile
Re: Feed Rates Not Same as Gcode
« Reply #1 on: May 26, 2011, 05:44:29 PM »
Your Z axis has a max velocity of 30 IPM, thus if there is a combination move the slower axis defines the feed rate.
RICH

Offline MattJ

*
  •  22 22
    • View Profile
Re: Feed Rates Not Same as Gcode
« Reply #2 on: May 26, 2011, 06:54:31 PM »
Rich, Thank You!
I just got home. I will make that adjustment right now.
Again, Thanks!

Offline MattJ

*
  •  22 22
    • View Profile
Re: Feed Rates Not Same as Gcode
« Reply #3 on: May 26, 2011, 07:51:42 PM »
I should have figured it would not be that easy.
Now I get a notice telling me that the PWM has been set to minimum.
I still get much slower feedrates than programed.

Offline BR549

*
  •  6,932 6,932
    • View Profile
Re: Feed Rates Not Same as Gcode
« Reply #4 on: May 26, 2011, 08:41:40 PM »
Try doing a simple test. Can each of your axis do the max vel as set in config?

Next try a long move in 3 axis at the same time   something like X10 Y10 Z5  do you reach programmed velocity.

It may be your gcode has too many short segments and the machine never gets a chance to reach max velocity.  Low accellaration values can cause this as well

Maybe your kernal speed is too low to reach max velocity?

Just a some thoughts, (;-) TP

Offline MattJ

*
  •  22 22
    • View Profile
Re: Feed Rates Not Same as Gcode
« Reply #5 on: May 26, 2011, 09:43:37 PM »
BR549, Thank You
I adjusted my accellaration higher and it did increase my feedrates!
They almost doubled, which is a big help.
I do believe you are correct about the short segment issue.
Obviously I am a newbie, maybe in ten or twenty years I might get a hang of this!
Thanks