# I want to understand the low level details please

**URL:** <https://forums.maslowcnc.com/t/i-want-to-understand-the-low-level-details-please/25110>\
**Category:** Ground Control\
**Tags:** groundcontrol\
**Created:** [October 26, 2025, 10:19pm UTC](https://forums.maslowcnc.com/t/i-want-to-understand-the-low-level-details-please/25110 "2025-10-26T22:19:15Z")\
**Posts on this page:** 5\
**Page:** 2

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**Author:** ![dlang](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/dlang/32/859_2.png) [@dlang](https://forums.maslowcnc.com/u/dlang)\
**Post date:** [December 7, 2025, 8:51pm UTC](https://forums.maslowcnc.com/t/i-want-to-understand-the-low-level-details-please/25110/21 "2025-12-07T20:51:52Z")

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Dave Covert wrote:

> 1. When the belt length sanity check fails, don¢t leave the unit in the apply  
> tension state, unable to be recovered until a firmware reboot. Maybe put it  
> into the Unknown state (which is accurate I think?) so that tension can be  
> released.

good point, whenever the maslow decides it doesn’t know where it is, it should  
switch to unknown

David Lang

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**Author:** ![bar](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/bar/32/10_2.png) [@bar](https://forums.maslowcnc.com/u/bar)\
**Post date:** [December 8, 2025, 6:56pm UTC](https://forums.maslowcnc.com/t/i-want-to-understand-the-low-level-details-please/25110/22 "2025-12-08T18:56:17Z")

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> [@Dave\_Covert](#):
>
> When the belt length sanity check fails, don’t leave the unit in the apply tension state, unable to be recovered until a firmware reboot. Maybe put it into the Unknown state (which is accurate I think?) so that tension can be released.

This is a great point. I would expect it to go back to the Extended Out state. I will look into that.

> [@Dave\_Covert](#):
>
> Thinking about future commercialization and customer support issue reduction, some users are going to do the same thing I have done; equating running a g-code file with running calibration and thinking that apply tension is appropriate before either. Perhaps set some value(s) in the yaml file to indicate that calibration is needed and disable the Apply Tension button until calibration has been completed successfully. Perhaps even set the values to require calibration when the issue above (failed sanity check) happens.

Unfortunately we don’t know if calibration is needed until apply tension is run. It should be a functional flow to do Extend → Apply Tension → Fails because calibration is needed → Run Calibration (without needing to retract or anything)

I’ll check that that is working right.

There certainly seems to be something in the flow which is confusing.

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<div class="post-metadata">

**Author:** ![dlang](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/dlang/32/859_2.png) [@dlang](https://forums.maslowcnc.com/u/dlang)\
**Post date:** [December 8, 2025, 8:52pm UTC](https://forums.maslowcnc.com/t/i-want-to-understand-the-low-level-details-please/25110/23 "2025-12-08T20:52:51Z")

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Bar wrote:

> > [@Dave\_Covert](#):
> >
> > When the belt length sanity check fails, don¢t leave the unit in the apply tension state, unable to be recovered until a firmware reboot. Maybe put it into the Unknown state (which is accurate I think?) so that tension can be released.
> 
> This is a great point. I would expect it to go back to the Extended Out state. I will look into that.

If it gets into the state where it says the belt lengths do not compute to a  
valid location, I think unknown is more accurate than extended out. When you are  
in extended out you should just need to apply tension, but when you have applied  
tension and the belts are tight, extended out doesn’t make sense.

> > [@Dave\_Covert](#):
> >
> > Thinking about future commercialization and customer support issue reduction, some users are going to do the same thing I have done; equating running a g-code file with running calibration and thinking that apply tension is appropriate before either. Perhaps set some value(s) in the yaml file to indicate that calibration is needed and disable the Apply Tension button until calibration has been completed successfully. Perhaps even set the values to require calibration when the issue above (failed sanity check) happens.
> 
> Unfortunately we don’t know if calibration is needed until apply tension is  
> run. It should be a functional flow to do Extend → Apply Tension → Fails  
> because calibration is needed → Run Calibration (without needing to retract  
> or anything)

should you be able to run calibration from state unknown?

or do we need a new state where the belt lengths are known, but do not compute  
with a valid frame size?

extended out only partially matches this.

David Lang

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**Author:** ![bar](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/bar/32/10_2.png) [@bar](https://forums.maslowcnc.com/u/bar)\
**Post date:** [December 8, 2025, 9:00pm UTC](https://forums.maslowcnc.com/t/i-want-to-understand-the-low-level-details-please/25110/24 "2025-12-08T21:00:35Z")

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> [@dlang](#):
>
> or do we need a new state where the belt lengths are known, but do not compute  
> with a valid frame size?

I think that this is exactly what Extended Out means. Extended Out just means that we know how far out the belts are extended.

I’ve had a case where I extended them out and pressed “Apply Tension” only to realize that one of the belts was stuck on something. After clearing it I could just press “Apply Tension” again and it would be ready to cut.

You can also find anchor point locations after pressing apply tension.

Applying tension shouldn’t change the state if it fails, the belts are still extended and we still know how long they are

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**Author:** ![dlang](https://yyz1.discourse-cdn.com/flex031/user_avatar/forums.maslowcnc.com/dlang/32/859_2.png) [@dlang](https://forums.maslowcnc.com/u/dlang)\
**Post date:** [December 8, 2025, 9:21pm UTC](https://forums.maslowcnc.com/t/i-want-to-understand-the-low-level-details-please/25110/25 "2025-12-08T21:21:12Z")

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Bar wrote:

> I think that this is exactly what Extended Out means. Extended Out just means  
> that we know how far out the belts are extended.

except if we don’t.

take the case of having a valid frame stored, you relax tension, shut down, and  
start up, but the encoders have moved enough that your belt lengths are invalid.  
apply tension, you are in a state where your belt lengths don’t match your  
anchor locations.

you don’t know if your belt lengths are wrong, your anchor points are wrong, or  
a belt got snagged on something and didn’t fully retract (as you used in your  
example)

David Lang

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