Mach 4 customize

Is there a way to set the default jog and rapid speed settings in Mach four when I first turn on the program ? they are by default set to 600 for rapid and 150 jog. I’d rather have 300 and 300.

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In the Machine.ini file, edit these:

drojograte = 20.000000
drorapidrate = 50.000000

They are the % numbers for the controls in the Mach4 screen. They are a percentage of the max speed in your mach 4 motors configuration. So if your motor’s max velocity is 600ipm, then set the drorapidrate to 50 and you will have 300ipm as the jog rate.

You can also edit those settings in the motor settings in Mach if you don’t want to dive into the Machine.ini file.

Not the percentages. I probably should have explained what those are a little better.

So for anyone interested…

The motor config in Mach4 (below) has the Velocity setting. That is the max velocity Mach 4 will let you jog, feed, or rapid move for that motor. So you set that at least as high as you will ever want to move that motor.

This section of the AVID screen (and many other mach 4 screens) allows you to set/override the rates on the fly.

The feed rate is comanded by the Gcode, and you have an ability to overide that (by the percentage at the top) above and below the commanded rate, as long as it does not exceede the Velocity setting in the motors tab.

The Rapid and Jog Rates are set as a percentage of the Velocity setting.
So I have my motor set to 1001, because I have one thing (fast laser rastering) that I want the X axis to run up to 1000ipm at. However, I don’t want to jog anywhere near that fast, so I keep it set to 20% (200ipm), and 500ipm is plenty fast for my rapid moves, so I leave that at 50%.

If at some time you want to jog at the full Velocity, and not the reduced value from the override, just hold down the shift key while you hit your jog key and it will run at full speed.

Note: there is only one display DRO for the Rapid and Jog Rates. So it will display the value of the rate percentage times the Velocity setting for MOTOR 0 (they had to pick one so they picked 0, which is the X axis on most AVID machines). However, the actual jog and rapid will be different for each motor as the shown percentage times that motors actual Velocity setting.

All 3 of those percentages will set back to their defaults when you restart Mach 4. The feed will just go back to 100%, but the jog and rapid numbers get set back to the below values from the machine.ini file. I presume this is to avoid you setting something for one session, and then having it be sticky to the next session and you not noticing that your next job is running 200% faster because you forgot to change your overrde back to 100%.

So you edit those if you want mach4 to startup with a different default.

drojograte = 20.000000
drorapidrate = 50.000000

This is a much more nuanced and better answer. Thanks @jjneeb

Thanks again for the quick responses I messed with that ini file and it looks like it does what I want it to do. The main reason I’m looking for this is I use my cnc daily but I shut down computer and stepper controller at night. Do you think that s nessary ? Or do you guys just leave them on?

I don’t think its necessary to shut down, but its also not a bad idea. I don’t use mine every day, so I shut it down. Steppers draw a decent amount of current when stationary to hold themselves in position, so they are not really ever “idle”. Your fans will wear out sooner as will all of your electronics.

Where do I find the rapidrate?
I only see the drojograte :confused:

Ah, I forgot I had modified my screenset to save off the rapidrate DRO as well.

I can’t remember what that used to do with the stock AVID screen, I think it probably resets the rapid rate adjustment to 100% everytime you load mach4?

Its pretty easy to change if you done a little screen editing before. Let me know if you want help, or a copy of my screen so you can copy the code from there.


Yes mine is 100% which I dont need and always set it 50%.
In the .ini file I cannot it…if I can do it in the ini that will be great… if not how to do this in the screenset…I have your screenset as well.


Ah, if you are using my screenset, just add the extra line for the DRO in the .ini file like this: