Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Speed tolerance based on present speed instead of top speed #12

Open
Meliusja opened this issue Aug 29, 2022 · 1 comment
Open

Speed tolerance based on present speed instead of top speed #12

Meliusja opened this issue Aug 29, 2022 · 1 comment

Comments

@Meliusja
Copy link

    if(settings.spindle.at_speed_tolerance > 0.0f) {
        spindle_data.rpm_low_limit = rpm / (1.0f + settings.spindle.at_speed_tolerance);
        spindle_data.rpm_high_limit = rpm * (1.0f + settings.spindle.at_speed_tolerance);
    }

This code from huanyang.c applies speed tolerance percentage to the present speed setpoint which implies that speed accuracy of VFDs improve as the speed decreases. For example a 10000 RPM motor with a 1% speed tolerance would be +/- 100 RPM at 10000RPM but +/- 10 RPM at 1000RPM. The physics governing speed accuracy on VFDs cause the the speed accuracy to be the same or worse as the speed decreases. I believe the speed tolerance should always be based on percentage of top speed.
Thanks,
Jeff

@terjeio
Copy link
Contributor

terjeio commented Sep 4, 2022

I believe the speed tolerance should always be based on percentage of top speed.

I do not believe so - but maybe there is a case for making it configurable?

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment
Labels
None yet
Projects
None yet
Development

No branches or pull requests

2 participants