Ermagherd, another K40 newbie!


Okay, first up - thanks to everyone in this community, notably @keen for gathering a lot of info together in one place to make it easy for someone who decided to take the plunge, and for @mcdanlj for putting it in an easy to find spot. (And preemptively to those who chime in with advice for me in the coming days/weeks/months…)

Anyways. After doing my research, I have currently on the way to me an analog “old style” K40, set to arrive next week. Initially I BRIEFLY thought about something like a Glowforge, but seems by all accounts to be equivalent to the K40, albeit with a better warranty and works out of the box) and for the sheer silly money of having a sleek little Glowforge, I could get a K40 and with a bit of effort turn it into something that’ll do everything I need for half the price.

Thanks to the aforementioned info, I’m planning on spending a day going over the thing with a fine toothed comb, paying special attention to the grounding points and the “accessory” outlets (which I plan on replacing with GROUNDED three pin outlets I already have from another project) as well as interlocks.

I will be immediately installing an air assist solution, although I go back and forth on whether to use a 3d printed nozzle with crosshair/diode, or get the Lightobject shiny blue one, and whether to supply air via the aquarium pump method, or via my shop compressor (with inline moisture/particulate filter installed along the way). Opinions on that are welcome.

I also plan on replacing the bed with a spring loaded one, found on Youtube.

Also, the control panel leaves a lot to be desired. To that end, I stumbled on a Youtube vid that others might find interesting. It incorporates a flow meter and water temp sensor, which I like, a better potentiometer, and… well, I’m a sucker for illuminated buttons!

But regarding that - I’m planning on replacing the control board, since I primarily use a Mac (I do have access to the wife’s windows laptop in a pinch, but not an ideal solution) so plan on using a combination of Adobe Illustrator and Lightburn. I’ve narrowed the choice to a Cohesion3d or Super Gerbil. Since I don’t plan on futzing with a Y axis (but a rotary is… interesting) I immediately leaned towards the Super Gerbil (especially since its half the price) but have heard a few stories about it taking an age to arrive, and it having… er, less than stellar track record and support, so now leaning Cohesion3D. I see it has a fairly familiar LCD/rotary encoder option (similar to my Prusa 3D printer) so wondering if I went that route, is the modified control panel now redundant?

Power supply - by all accounts isn’t great? Is it smart/intelligent to just replace it right off the bat with something like the Mean Well RT-85D which will provide a more stable solution, as well as handling 12v LED lights? (And would 2A of 24V be enough to power the K40 and the Cohesion3D?) At least would get me rewiring everything, which means everything would get verified in the process.

Phew. Looking forward to getting started with it! (All this because Ponoko jacked their prices!)

I’d suggest second 24V supply — better off driving the stepper motors at 24V. You can get 24V LED strips, or use a $2 buck converter to down-convert the 24V to 12V for LEDs.

My perspective on your questions, lots of experiences and options in this forum… all are correct :slight_smile:

I use the light object assist because it was easy to implement. My laser pointer is separate but I really don’t use it anymore. I line up the object and test fire to an alignment target positioning with Lightburn.

I used both an aquarium pump and an airbrush pump, hated them both. The shop air is too noisy and I did not like running hoses.
I have been very happy with it has plenty of capacity easy to adjust and pretty quiet. I also added this flow meter which @Nedman recommended and is also using:

The spring-loaded bed is a good starting point, in fact I designed one. However, I ended up with the LO bed as it gave me more options for holding thicker and varied shapes. Much easier to control but requires some more electronics… can you have to much electronics??

If you go with the C3D make space for the LCD panel. The flow meter is interesting but it does not avoid a disaster. Add a flow sensor switch into the LPS interlocks so when you forget to look at the flowmeter your tube doesn’t blow up.

Of course, add interlocks to the covers or this forum will hate you :).

so now leaning Cohesion3D. I see it has a fairly familiar LCD/rotary encoder option (similar to my Prusa 3D printer) so wondering if I went that route, is the modified control panel now redundant?

I am running a smoothie 5 and have been happy with it combined with Lightburn.C3D was not avail at the time but if it was I would have gotten it. The smoothie 5 is just an overkill but good technology. Keep in mind with smoothie compatible controllers you get an open-source LCD panel if you want to implement it.
The K40 control panel functions are independent of the control panel so I do not see any redundancy???

I would use the existing LPS until it dies. There are better supplies but they are also a lot more expensive. The only reason I would replace the LPS is if I changed the laser power.

I would recommend a small 12V supply for accessories and a beefy 24V supply. The difference in cost between 5-10Amp 24VDC switchers is not worth the worry of underpowering the unit.

A lot more or my history with K40 is here:

Enjoy and welcome to the addiction!

Are you planning to do primarily cutting or engraving?