Buildbotics Forum

I was able to configure my laser using the PWM spindle options outlined in a previous post from Doug. It all worked perfectly until I homed the machine. This is repeatable behavior. Power on machine PWM signal between 0-3.3V works as expected and variations within. However, if I home the machine it no longer sends any signal unless I invert the PWM setting then it will sit solid at 3.3V no matter what M3 S# I send it. All of the limit switches are using shielded cable and work as expected.

Triggering the end stops manually or jogging the machine seem to have no problem so it seems maybe software related?

I just tested the PWM output on my machine. I am running 0.4.14 software. It seems to work fine both before and after homing.

Here are a few things to consider:
1. Many lasers will not work with the 3.3V PWM output. They require a 5Volt PWM signal to work correctly. I even found that the new versions of the Ox Laser that I blogged about a couple of years do not work with PWM outputs. New JTech lasers are now able to work with 3.3 Volt PWM. However, JTech lasers that were made more than about a month ago would not. Your situation is a little strange because it seems to work before homing, but not after. It could be right on the ragged edge. Unless you know for a fact that your laser is compatible with 3.3V PWM signals, I recommend trying a 3.3V to 5 Volt level shifter. Here is a link to one that should work. https://www.sparkfun.com/products/12009 If you choose this one, you will only use one of the four channels.
2. If you have 'dynamic-power' enabled, the laser will not come on unless you are making a cutting move (e.g. G1).
3. If you have 'rapid-auto-off' enabled, the laser will be off during rapid moves.

Hey Doug!

Thanks for your help, as always. I do have a brand new (Arrived directly from them on Wednesday) JTechPhotonics laser. And I confirmed with a multimeter that the controller was not even send a signal after homing. And also the laser works totally fine as long as I don’t home which I think rules out any compatibility issues. Today I’m not having the issue. The only change I’ve made was unchecking the dynamic power setting in the tool settings. Will try to edit back and see if the issue returns but currently running a project.

Hi....the recurrence yield of your VFD and consequently shaft speed, is controlled by a 0-10Volts input. This 0-10Volts is produced by a computerized to simple converter which is important for your C32 BoB. This voltage is thusly gotten from the PWM signal that is delivered by your ESS. The reach and size of this PWM signal is dictated by your Mach4 axle settings and the suitable S#### order which are then shipped off the ESS.

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