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Machine running in slow motion
« on: February 21, 2014, 08:49:51 AM »
I have my velocity set to 400 ipm, When I jog all axis move  very fast. But when I run the Heart program it runs in slow motion. It takes a half hour to complete. I am definitely a Newbie and quite possibly a Idiot. Any help would be appreciated. Thanks Art

Offline Hood

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Re: Machine running in slow motion
« Reply #1 on: February 21, 2014, 10:43:35 AM »
If you attach both your code and your xml I will have a look.
Hood
Re: Machine running in slow motion
« Reply #2 on: February 21, 2014, 11:31:17 AM »
I increased my acceleration from 50 to 62 and machine now runs the Heart quickly. I have to search the forum to see how to find xml . But it is the heart program in the Mach 3 gcode file folder. I guess I don't understand the relationship between Velocity and Acceleration. Thank you very much Art

Offline RICH

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Re: Machine running in slow motion
« Reply #3 on: February 21, 2014, 09:45:38 PM »
Quote
I guess I don't understand the relationship between Velocity and Acceleration
Velocity is a constant rate of speed in time with motion in a direction.
The velocity you input in motor tuning is the max velocity you can use reliably with your machine.

Acceleration is a change in velocity with repsect to time.
See pic

RICH

Offline Fastest1

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Re: Machine running in slow motion
« Reply #4 on: February 21, 2014, 10:39:09 PM »
In laymans terms.

Velocity is the max speed an axis can obtain.
Accel is the amount of time it takes to reach that speed.

I am still trying to understand what Rich said. He probably said it correctly though ;-) If Lupe parked the car on the 50 yard line and..... nvm

Do you have your feed rate on 100% on the program page of Mach? that could explain the difference between the jogging and machining speeds.

Dont worry about being a noob. We all were once. BTW I r an idiot 2.
« Last Edit: February 21, 2014, 10:41:00 PM by Fastest1 »
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)

Offline RICH

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Re: Machine running in slow motion
« Reply #5 on: February 22, 2014, 05:35:48 AM »
Quote
I am still trying to understand what Rich said
.

- cruise control - 60 mph on the turnpike....constant speed and no direction
--        "                    "                         going north  velocity  / motion in a direction ( velocity is a vector quantity)

- sitting at the light with the car, revving her up, pop the clutch, 0 to 60 in 4 seconds - zero velocity to 60 mph in 4 sec ........ acceleration
-- 60 mph on the turnpike going north......floor the gas peddle ..60 to 80 mph in 3 sec - change in velocity in a time frame

-------------------------------------------------------------------------

Acceleration and velocity are related and frankly it gets complex quickly since what we are realy talking about is the ability of the
motor to make the axes move. Mach controls how the motor is going to spin but the machine and machining  limits the motor
movement. 

So in general you have the following:

In practical applications one defines an acceleration desired and finds what is required to achieve it ….or ….. accepts the value based on some other parameters. One could say that they are either designing a system to achieve the task or they accept their system
“ as is “ and the acceleration is defined by what they have.

RICH ;)

Offline nobby

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Re: Machine running in slow motion
« Reply #6 on: February 22, 2014, 10:13:00 AM »
hello
did you unplug the controller knob from the break out board
as it maybe set to feedrate control as standard
I just did this myself and was scratching my head for a while, as it overides the feedrate on screen if its set that way -  but unplugged.
« Last Edit: February 22, 2014, 10:14:57 AM by nobby »

Offline Fastest1

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Machine running in slow motion
« Reply #7 on: February 22, 2014, 11:07:58 AM »
What is a controller knob?
I want to die in my sleep like my grandfather, not like the passengers in the car! :-)

Offline nobby

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Re: Machine running in slow motion
« Reply #8 on: February 22, 2014, 02:14:21 PM »
What is a controller knob?

he may have the plug in thing for the bob set to feed rate - over ridsing the onscreen settings
when its unplugged it defaults to 1? as the feed-rate instead of 100?
so his half hour job should have been 100 times faster on full feed rate?

-I only guess this as I just did this today whilst changing my 64 imperial steps per at 26500 to metric 50 at 20000, I unplugged the control knob doofer, then run the exact same 100 by 50mm box and it slowed right down

after I switched back to 64 imperial then backl again, then again and one more for luck, after changing the 20000 steps per to 200000, did I then think to retrace my steps and plug back in the controller knob doofer, and it came back. wasting a few hours that I should have been doing the limit switches.
Re: Machine running in slow motion
« Reply #9 on: February 23, 2014, 08:46:08 AM »
Thanks for all the help.  Art