Joe, I'll be following your build since that is something I plan on doing too. If you don't mind, can you also post files of parts that you made yourself, like parts from acrylic. The dxf files will be best.

 

Can you still cut through 3mm ply at the furthest corner? Just curious how size affects cutting power.

 

Hey, cool build!

Just noticing a couple serious safety concerns I feel I should bring to your attention (or others reading this with similar plans):

1. Decoupled dual drive Y motors:
I wrote a lenghtier explanation here: A Few General CO2 Questions but basically you always want a rigid mechanical connection between the two sides, preferably a driveshaft driving two belts. Reason being, that if one motor skips a step, the angle of your X gantry changes - can easily then miss the no3 mirror and shoot out the side. I couldnt find the video, but I had one of a local makerspace where someone knocked the mirror just a little while removing material, and the video included pictures of the burnt down booth next door. Even an unfocussed CO2 beam easily ignites cloth. Really, don't take a chance on this one!

2. Enclosure: You really want to enclose that machine:
2.1 Fumes: You will have a hard time extracting fumes from an open frame: in an enclosure, a little negative pressure extraction, means fumes go where they need to be: not into your lungs kicking off the cancer
2.2: Reflections / stray beams: Don't need to say more self explanatory
2.3: Restricting access to the 22kv supply: More than enough to stop your heart!
2.4: Earth path for Arcs: As your tube ages, and moisture in the air breaks down the HV transformers in the PSU, its just a matter of time until the path of least resistance becomes the open air + frame instead of the tube: Every single one of my laser tubes before replacement, arced to the case. In a enclosure, if its properly designed, the path to earth is an enclosed box, usually isolated from the main chassis, around the HV/Tube/wiring with a direct path to earth, usually through an earth spike. Its also wired to mains earth, and the chassis. If an arc to the case happens (well, not if, when, its inevitable) the farraday effect should allow the discharge voltage to flow through the inside skin of the case to the earth wiring. With a bare alu frame, the faraday effect is no longer on your side. My first laser was built the same (except with proper mild steel panels attached, see https://openbuilds.com/threads/v-slot-co2-laser-60-100w.617) - and i have first hand experience of this. In my case it was just a ruined motherboard, and no injury... But that was more luck: When I did version 2 (https://openbuilds.com/threads/openbuilds-freeburn-2-mini-v-slot-co2-laser-40-50w.1112/) I opted for a full enclosure instead!

 

Joe,

thanks for your info and guidance. I too am building an ACRO based laser cutter I hope. Although my laser is not a CO2 at least to get started. I am starting with a Raspberry Pi with the CNC hat as there are no XPRO available at this time. Great stuff I will be following your work closely.

Yves...

 

Questio here??, Why the 5v in the Drain Pin of the mosfet? Im about to start my conversion today just waiting on UPS to arrive with the k40

 

So are you regulating the k40 tube power with PWM? or just the mosfet as a on off switch?

 

Can you elaborate a bit on the reverse logic powering the tube power supply, what I understand is that 5v is need it to maintain the laser off?

 

Im a airline pilot, so electrical engineering is a bit out of my normal knowledge until a lot of reading and understanding, also in your pics i saw two power supplies plus the tube one, this can be done with 12v or 24 v is need it?

 

This is the model im getting today but you know how china products are, as soon i get the box ill confirm that it is a similar product as yours then we discuss if you dont mind that electronic Logic and thanks for your time.

 

ir is here im impresed with the packaging

 

Really surprise with the package but still the same junk, BTW this thing arrive in two days "free Shipping" from Tennessee, the rail system and belts feels all loose i dont know how this thing can even make perfect circles, ill post the out come later, i need to sleep just came back from a flight and this thing is scary so later tonite ill fire it up.

 

It works can I put it apart now????

 

K40 Whisperer, mirrors came very good align

 

A lot to learn about this dangerous machine i got bite just at 10% of power in my small finger, dam that hurts, but i think is a normal way to learn that this stuff are not toys, power settings speeds etc but impressed how this thing cut a 1/4 inch acrylic like a hot knife thru butter "White Acrylic",, i will experiment a bit more with it before destroying it for this great idea
K40 ACRO Conversion,