K40 Mods

Hey all! New to the forums. Just got a k40 and decided to do a complete rebuild. I pretty much gutted the enclosure and am in the process of adding a lot of the recommended safety features, such as interlocks, water flow shutoff, etc. I’m fairly new to this type of stuff (lasers and electrical circuits). I know enough to get by, but otherwise a noob. I understand the voltage of the laser is dangerous and that I should be careful.

I bought the laser used off Marketplace and it has an upgraded Monport board so it is compatible with Lightburn. As a result, there were a lot of unused cables in the enclosure, which I’ve removed. The guy I bought it from said one side effect of the upgraded board was none of the buttons on control panel work, except the on/off switch. It seems like this is expected, and all control is done via Lightburn. I didn’t know if it was possible to wire things up so they’d function in addition to the control via the board, or not. If not, I wondered about removing them. Any tips or suggestions here?


Just wanted to expand the post a bit. Page 4 of the attached manual lists the ports on the board and their use.
GRBL_Controller_User_Manual_62d2cafd-0128-403c-af4b-6e43720b9b8d.pdf (1.1 MB)

Can someone provide a brief, real world example (or point me to a link) of what some of these might be used for? Items 1-13 are fairly obvious, but I’m not sure what 14-26 would be used for. I’m most interested in the PWM output signals and the temp controller signals and what I might use them for.

Sorry if these questions are basic. I’m just trying to learn as I reassemble my k40 and see if there are other modifications I should make.

Yesterday, I discovered my k40 has the plastic washers which I replaced and I had to remove paint from the chassis to ensure a proper ground as noted in the Light and Electricity page.
Thanks again

The manual does seem a bit light on details!

Probably the PWM signals are all controlled from the same pins, and follow spindle or laser control depending on the $32 setting.

20-23 might be connected to the enable signal for those axes if you are using external drivers but it’s not clear to me why. They do have four-pin headers in the middle (not labelled) for external stepper drivers.

I wish Monport had engaged here instead of spamming us so that we could reasonably just ask them.

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Thanks! Appreciate the insight. For now, I think I’m going to add some of the easier safety additions, like interlocks and the water flow sensor and then reassemble.

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