Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: kak on May 25, 2009, 06:21:24 PM

Title: feed rate question
Post by: kak on May 25, 2009, 06:21:24 PM
Hello

I´m having problems with feed rate.  I don`t have much experience with cnc, but which program has the final priority when you choose the feedrate?
I can see you can change it in the Cam software, tool options and Mach3.
Right now I use blue foam to learn it, so it is "save" to use.

I loaded a Gcode today, and the feedrate override led was on. Does it mean that the motors will run faster then I wrote in the Motor tuning window? Is it possible?

Adam
Title: Re: feed rate question
Post by: Hood on May 26, 2009, 03:05:21 AM
Unless you are using an old version of Mach then the Feed Override will never exceed the rapid axis speed set in motor tuning. It is your code that will determine the feedrate but of course you can manually override that with the FRO, either up or down. The FRO will always be a % of the commanded speed so for instance if your code calls for a F100 and you have the FRO set to 50% you will get a feed of 50, if however the next line of code has F50 in it then because you still have the FRO at 50% your feed will be 25.

Hood
Title: Re: feed rate question
Post by: Chris.Botha on May 26, 2009, 03:26:25 AM
i cut almost everything at 800mm/min but i path at 400mm/min for one simple reason.. the initial plunge is where i break cutters so normally i would have to manually add some feedrates  into my code to make the plunge at  400 mm/min but after a few passes bring it back up to 800mm/min, but since i now have mach i simply path at 400 and after the cutter is in safely i simply crank FRO up till im happy.. i have to do this manually as my spindle cannot be controlled by mach either at this point in the game apparently.. NSK 2530E


not yet played with my motor tuning to give me 1200mm/min so im stuck at 800 for now.. but soon

so in answer to your question.. no software has priority over your feedrate.. since you control mach, at the end of the day you control your feedrate..  i have noticed however my particular screenset wont allow me to override by more than 300%...
Title: Re: feed rate question
Post by: Chris.Botha on May 26, 2009, 03:27:57 AM
actually on that note.. anyone else use a nsk2530 and have control over on/off and speed?

the controller unit is fully computerised with lots of io ports.. cant imagine it would be a hard thing to do?