Setting Pulses per Revolution

[clover]

Setting my Masso up, my question is: I am using a Gecko G540 driver which is hardwired to 10 microsteps.

What do I set the pulses per revolution up to -

1) Native resolution of the steppers, eg 200.

2) The stepper resolution times the microsteps eg 2000

The latter I hope else I will be struggling for resolution! Many thanks.

 

[masso-support]

Yes, that would 200 * 10 = 2000 pulses per rev into the MASSO settings.

 

[clover]

That's a relief, thank you.

Just curious, so how does the Masso know that the G540 does 10 microsteps as distinct from say 4 or 8 or whatever from a different driver? Do I need to input that info anywhere?

 

[masso-support]

That is why in MASSO settings you put in the value after calculating the micro stepping settings, this way its the total number of pulses after micro stepping and also after knowing the motor step angle because this can also be different in some motors.

 

[clover]

Yes, that's makes sense - thank you.

Taking it a bit further, attached is a screen grab of one of the axis settings windows I get when I plug in my numbers. I have a question about the Axis resolution.

The 0.0200 mm figure is obvious (40mm/2000). The max pulse rate is stated as 0.8kHz (800 Hz). Does this mean that my Maximum Feedrate is: 0.02 x 800 = 16mm/sec (0.63 ins/sec)?

Thank you for answering my dumb questions, I guess the trade-off is that it may later help another Masso beginner struggling to understand.

 

[masso-support]

You can simply see the feedrate in the feedrate field you have entered 1000 mm/min, the calculation displayed in blue colour is based on all the values including feedrate that you enter and will change if you increase the feedrate, hope this explains your question.

 

[pluggs]

Hi this post did help a newby as I had my pulse rate to drive my g540 set to only 200, anyway from the above screen grab what should you set the acceleration to ?

 

[masso-support]

Hi pluggs

Acceleration is a a hard one to guess because it is specific to your machine. It is dependent on motor torque, the mass of your gantry, frictional losses and is something you will find by trial and error.

On my machine I use 400mm/sec (16 in/sec) and that is for my setup which runs at 15000mm/min (600in/min). If you set this too high you will loose steps or stall the axis and if you set it too low it will take longer to get your gantry up to your maximum speed, but you are better off too low than too high. Remember that the value is per second squared so a low value will still get you up to speed very quickly and in my case it reaches maximum speed in less than a second.

Mine is about 1/35th of the maximum speed so than might be a good starting point and see how it goes for you.

Cheers

Peter

 

[pluggs]

Thanks Pete, so good to know there is no hard or fast rules on this one, initially playing around with the settings I had the acceleration set low and the speed high which resulted in the machine overrunning the proximity sensors and crashing into the hard stops as it wasn't breaking in time, I learnt quickly to have the stepper do more work breaking, I will keep playing with this number once I have my machine fully functioning, I think I have my nema34 set at 500mm/sec at the moment. Thanks again.