K40 Laser Conversion

CNCModeller

Hi All,
My K40 lives again!

Just wondering if I'm doing anything dodgy from a safety perspective.

The docs for a Duet2 laser setup calls for a separate level shifter circuit, and use of an expansion header pin. However I'm using a 3-30v opto isolator board driven from the 24v E0 heater closing the fire pins. I'm assuming the e0 heater output is good in terms of controlling fire safety related equipment?

I have door and laser safety switch on the control panel, I'm going to add a coolant flow sensor interlock too. Probably based on a fan speed pwm input, if I can figure out how to do it.

Just been dialling in the skew compensation as my laser alignment isn't great.

A local 12864 control panel is next on the list.

Any constructive feedback would be much appreciated

All the best
Barry M

jay_s_uk

@CNCModeller I've wired the laser fire on mine directly to the bed heater negative
Here's a good resource https://github.com/TeamGloomy/LPC-STM32-RRFUserConfigs/tree/master/K40 CO2 Laser - SKR 2 - ESP - paulg4h

o_lampe

@CNCModeller The biggest issue I see is the ribbon cable for the X-stepper. It might be good enough for the endstops, but if you want to upgrade the X-stepper with a bigger (faster) motor, you're in trouble.

Using the original K40 housing is another thing. Mine is very flexible and mirror adjustment is a new hobby for me.
I'm currently happy with the A4 sized workarea, but one day, I'll build a solid frame from extrusions and panels.

CNCModeller

@o_lampe I'm hoping get the laser functionality up to scratch and then eventually transfer everything over to a larger enclosure, motorized bed, and xy motion platform.

In the short term A4 is big enough for me as I'm only cutting small reinforcement and mounting plates for radio controlled aircraft.

Before I do the swap to a larger setup would it be worth gluing and screwing a sheet of 20mm ply to the outside of the base of printer enclosure to stiffen things up? Or do you think it's more the internal structure that's moving?

All the best
Barry M

o_lampe

@CNCModeller In my case it's definitely the housing. The bottom which holds the whole mechanic has a huge bulge which can jump inwards or outwards.
Some people use extrusion profiles to fix it but thick plywood would also work I guess. Don't close all the vent holes.