Laser Monitoring

Hi all, I’d like to propose a project, but I’ll need help with it :slight_smile:

These are just some initial thoughts.

For the new laser cutter, there are a bunch of safety and general-interest things I’d like to monitor, and log over time.


  • Physical display of the main parameters
  • Data-logged to some web-accessible place
  • Certain parameters tied in to the safety cut-out

Parameters To Monitor

  1. Temperature of the coolant water in the reservoir
  2. Flow rate of the water in the coolant system
  3. Flow rate of the air out of the case
  4. Pressure of the air in the air-assist (maybe?)
  5. Temperature of the air inside the main case
  6. Current going to the laser
  7. Switch-position sensor for Board power
  8. Switch-position sensor for Water power,
  9. Switch-position sensor for Air power and
  10. Switch-position sensor for Laser power

Critical Values

From the above list, if Laser Power is on (10):

  • 7 must be ‘on’
  • 8 must be ‘on’
  • 9 must be ‘on’
  • 1 should be below some set value, otherwise treat as E-Stop.
  • 2 should be above some set value, otherwise treat as E-Stop.
  • 3 should be above some sett value, otherwise treat as E-Stop.
  • 4 is probably not a sky-is-falling problem, but should probably alert if <ambient.
  • 5 should be below some set value, otherwise treat as E-Stop and ring all the bells.
  • 6 should be below some set value, otherwise treat as E-Stop.

Number 6 will be useful because that will basically say when the system is being used, how much and how long for.

Some possibly relevant links: rLab Laser Monitoring

In the meantime, I will attempt to add the critical bits first using whatever comes to hand.

For example an ammeter like this

Hmm you didn’t include any type of metering regarding usage, this will be useful for mileage counting (aging of critical parts) and also potentially charging for usage of the laser cutter and or consumables?

Yep, I ended with:

I’m loving the retro current meter !

I’d be happy to offer some help with this, we can have a chat about it on Friday.

The only tweak I’d make to your suggestion is to have two thresholds on some of the values. So there’e one for “Don’t start a job at this value”, and one which triggers “Halt current job”.

1 Like